Golf Analytics

How Golfers Win

Monthly Archives: October 2014

Research on Pyschological Impacts on Performance

I have written a lot on the consistency of performance and using past performance to predict future performance. Once you have the data, those studies are straightforward to conduct and produce intuitive results. I’ve neglected much discussion of the mental side of the game because, on the whole, there isn’t any data out there that directly measures whether a player is confident, nervous, distracted, overwhelmed, able to cope with pressure, etc. I’ve just read two papers – Confidence Enhanced Performance by Rosenqvist & Skans and The Impact of Pressure on Performance by Hickman & Metz – that attempt to measure the psychological impacts on performance inherent in golf using performance data.

Confidence Enhanced Performance:

Rosenqvist & Skans use European Tour data from the past decade to measure the impact of confidence on performance. Because of the existence of the cut in most tournaments and the natural division of the field into successes and failures by the cut, it’s possible to look at how making or missing the cut affects performance in the subsequent tournament. Players who make or miss the cut are separated by very small differences in performance (as little as a single stroke for those directly on either side of the cut line) and are also nearly identical in terms of long-term talent. That means we should expect their performances to be similar in subsequent weeks – assuming that there isn’t any impact from prior weeks.

What Rosenqvist & Skans find is that there is a difference in performance between those who barely made the cut and those who barely missed the cut (they create these groups using players within six strokes of the cut in either direction, though they also compared smaller ranges). Players who just made the cut in the treatment tournament are ~3% more likely to make it in the outcome tournament. Players who make the cut also play ~0.125 strokes better per round in the first two rounds of the following tournament. The authors explain this outcome as a product of enhanced or diminished confidence effecting the players’s performance.

I’ve found similar impacts on performance in my own work. Players who exceed their normal or expected performance one week retain a small portion of that over-performance the following week; that is, they continue to perform slightly better the following week. The same is true for those who play worse than expected. It’s very difficult to say precisely why this occurs.

The authors say it’s because the player in question is more or less confident than normal. They designed their study to directly compare players with similar performance who were clearly separated into successes and failures. However, the difference in strokes between making and missing the cut is still large – even comparing only those players on either side of the cut line. In their study, the smallest range they examined was those players within four strokes to either side of the cut line. There is still a substantial difference in performance between the two groups; the missed cut group on average played one stroke per round worse than the cut line and the made cut group on average played one stroke per round better than the cut line. That shows a two stroke difference between the two groups of players. The authors showed that both groups were comprised of fairly similar players, so the made cut group slightly overachieved by roughly one stroke per round and the missed cut group slightly underachieved by roughly one stroke per round.

So the authors were not comparing players who were separated only into a successful and an unsuccessful group. They were comparing players who were successful/had overachieved versus a group who were unsuccessful/had underachieved. It’s impossible, with this data, to state that the observed differences in making or missing the next cut can be explained by confidence versus other factors. The slightly higher probability of making the cut in subsequent tournaments can be just as easily explained by saying the player’s swing was slightly better than normal or that his mind/body were in better physical condition. Teasing apart the impact of psychological vs. physical is difficult – perhaps impossible without administering a psychological evaluation and analyzing Trackman launch monitor data.

The authors’s finding of a small carry-over in performance is the important discovery, though. They show that players who perform well the previous week perform slightly better the following week than those who did not perform well the previous week – by around 0.125 strokes per round. However, this impact is extremely small and is surely overstated by those writing about and discussing golf. Good play the previous week only barely increases the probability that you will play well the following week. This reinforces the importance of looking at long-term performance when attempting to predict future performance.

The Impact of Pressure on Performance:

Hickman & Metz use Shot Link data to examine the probability of making a putt on the last hole of a tournament, considering the amount of money riding on the putt, the distance of the putt, the experience of the player, the amount of money the player won in the previous season, and the putting performance of the player so far in the tournament. They find that for every ~$30,000 that is riding on a putt (ie, if someone makes they win $100,000 and if they miss they win $70,000) the probability of making the putt drops by 1% all else being equal. They also find that this most impacts short putts of between 3 to 12 feet.

I don’t have much to say about this study except that I wish the authors had included a better control for putting ability. They controlled for ability using Total Putts Gained (basically Strokes Gained Putting throughout the tournament). Unfortunately, putting performance in small samples like one tournament is essentially noise. If you know how well a player putts in general, how well they are putting in a tournament isn’t predictive at all. In their study you’ll see that TPG is a significant factor in predicting the probability of making a putt, but if you look at the coefficients you can see that for every Total Putt Gained in the tournament (or for every 0.25 TPG in each round) the probability of making a putt increases by 0.9%. Over 18 holes this would translate to 0.16 putts gained. So players who putt well, in general, will tend to putt well in a tournament, so they’ll tend to make slightly more putts on the 18th hole. I don’t think this effects their results, but I do wish they’d controlled for ability in a better way. It’s possible that good putters block out the pressure better, or that bad putters are less affected by pressure.

Edit: It’s also unclear whether they take putts gained on the final hole out of their TPG measure.

However, the effect they’ve found is significant in terms of examining the impact of pressure. It indicates that for putts with very large differences in prize money (for example the Bubba Watson example they quoted on page 9 where $300,000 was on the line) the difference in probability of making the putt compared to a non-pressure situation could be up to 10%.

The Impact of Tournament Position on Performance:

I’ve dug into my database of results for the last half decade and examined the impact on performance of starting position in terms of strokes behind the leader. I’ve found two interesting results: 1. players who begin the second and fourth rounds a large number of strokes behind the leader perform worse than expected (I have compared all performance to my expected z-score performance) and 2. players who begin the fourth round in the lead or one stroke back perform worse than those who begin the round near the leader, but further back. For #1, it’s possible that these players are out-of-form (whether because of injury, swing, fatigue, etc.) or that they’re “giving-up” – focusing less because there’s less on the line for them. For #2, I suggest that players near the lead “choke” or play slightly worse than normal because of pressure.

It’s the nature of a golf tournament that after the second round a cut is taken that eliminates the worse half of the field. After the fourth round, prize money is awarded based on finish –  with those at the top earning as much as 17% of the purse and most of those near the bottom earning prizes of around 0.5-1% of the purse. In other words, players who begin the second round far behind the leaders normally will not be able to make the cut, while those who begin the fourth round far behind the leaders are normally locked into a very small prize. This means that players who are near the bottom beginning the second and fourth rounds aren’t playing for much; the first group is likely to miss the cut and earn nothing while the second group is largely locked into a small prize. I’ve found the negative impact on performance to be as much as a quarter to half a stroke for those near the bottom of a leaderboard (the green and blue lines on the below graph). It’s impossible, with this data, to attribute this effect to “giving-up” or to physical factors – out-of-form swing, injury, fatigue, etc.

impact of starting position

Similarly, if you focus on the fourth round results in blue, you can see that players in positions zero and one strokes behind the leader performed approximately 0.1 strokes worse than expected while those in positions two to seven strokes behind the leader performed approximately 0.06 strokes better than expected. All of these players had a reason to remain fully engaged mentally with the tournament. Those finishing in the positions they started the round in stand to earn the large prizes. This shows that players who begin the round in or near the lead typically play slightly worse than would be expected by their prior performance, and more importantly that the same is not true for players who begin the round in close positions, but not in or right behind the leader. This reinforces the idea that pressure exerts a negative effect on those in the lead.

I also should address the red line for the third round. Players in the third round begin in opposite order of performance so far, meaning those furthest back of the leader tee of early, while those closest to the leader tee off late. PGA Tour courses play more difficult, in general, in the afternoon than the morning. Steven Rachesky found a difference of roughly 0.15 strokes between early and late tee-times – similar to the results I’ve observed from my data. That is the major reason why the data for the third round looks drastically different.


McGladrey Classic Preview

The PGA Tour returns to Sea Island for the fifth McGladrey Classic this week. The par 70 Seaside Course winds through tidal flats, marshes, and dunes to create a fairly unique course among the venues visited by the PGA Tour. Most fairways are exposed to the wind, like on many coastal courses, but hazards also threaten on about half the tee shots – often left and right. This places a premium on controlling ball-flight and hitting fairways. Players hit fewer drivers here than on almost any other course the Tour plays just for that reason. The course is relatively short, even for a par 70, and doesn’t require many long carries with an iron.

The field isn’t particularly strong – though no worse than the past two weeks – and has some star power at the top with three Ryder Cuppers, Chris Kirk, and Bill Haas. The attention this week will be on the rookies – particularly the long hitting Tony Finau, who is working off a T12 and T7 to start the season. Seaside is a course that harshly punishes bad misses off the tee; learning where you can miss while still playing a proactive, birdie-seeking game is important for the rookies. Interestingly, the rough is very benign compared to normal. A player who misses fairways, but doesn’t find the hazards will do fine this week.

Course Fit:

Recognizing that the course history here is only four years and ~500 players, I looked into what types of players succeed here. I controlled for putting performance, meaning I’m looking at performance relative to the field ignoring any shots on the green. I’m interested in how a player’s tee to green style affects their performance at Seaside. I also controlled for player ability as represented by my z-score ratings; unsurprisingly these proved to be the most important piece of the predictive puzzle. However, I also looked at measured driving distance (ie, how far can you hit tee-shots), driving accuracy, and greens in regulation.

The results showed that players who hit more fairways on average (and this can be a result of cautious play off the tee and/or greater accuracy off the tee) perform better than normal at Seaside. Each extra fairway hit above PGA Tour average is worth about 0.4 strokes better performance than at an average PGA Tour event. In comparison, ability to hit for distance off the tee showed no correlation with success here. That’s likely because of how few drivers are hit off the tee here; the long hitters have few opportunities to shine here. Hitting greens isn’t much of a separator either because they’re large and easy to hit.

The ideal player here is one who builds their success off their mid-irons – Webb Simpson and Chad Campbell come to mind. Most players can get around this course by staying out of trouble off the tee and hitting the greens. To actually win you can’t be suckered into that survival game because there are birdies available for good iron players.

Tee-shot Strategy:

Overall, I estimate players hit driver on only 59% of their par 4/5 tee-shots last season – substantially fewer than the around 70% Tour average. Lay-ups are most common on #1, #2, #4, #8, #10, #13, and #14; players hit driver less than half the time on those holes last year. I don’t have enough data to map out trends in successful strategies.

At #1, the fairway is very wide up until around 265 yards off the tee, before it tapers quickly and two bunkers lurk to the right. Playing a lay-up results in a 160+ yard second shot, but allows for a straight-forward shot from the fairway.

At #2, there’s water/marsh in play on both left and right misses and the tee-shot is completely exposed to a left-right wind. The play here for most was the lay-up into the 250-280 yard range where the fairway is inviting and the worst miss is left into a fairway bunker.

#4 is the signature hole on the course for me. It’s an extreme dog leg left with the marsh in play off the left side and a bunker long to capture anyone playing aggressively down the right side. Most laid-up to the fat part of the fairway leaving ~170 to the pin.

#8 only offers trouble long. The green falls just short of drivable from the back tees. A shot of < 260 yards onto the extremely wide fairway is safe; anything beyond must avoid a waste area left, two bunkers guarding either side at 260-280 yards, and a bunker in front of the greens, as well as hit a fairway that’s as narrow as 16 yards. Any miss right aiming towards the green is swallowed by the trees short left.

#10 has water left off the tee and a large bunker right. The safe zone for longer hitters hitting driver is less than 45 yards between the water and bunker, making driver off the tee an extremely dangerous shot. Anything short of 280 yards is likely fine absent an extremely wide miss to the left.

#13 has bunkers long and right and a marshy channel right. In the limited sample of data I have driver was the better option for longer hitters; there’s not a ton of risk with the water far to the left.

#14 is the last lay-up hole before almost everyone takes out driver down the stretch. This hole offers a completely exposed tee-shot next to the water, aiming at a tiny safe landing area between trees right and marsh/native area left. The cautious play is anything between 260 and 280 – avoiding the bunker/tree right. That does leave almost 190 yards for the second shot.

Tee-shot Strategy at Las Vegas

This post applies my method explained in last week’s Open post to evaluate club selection using a mathematical model. Club selection is not noted in the play-by-play, requiring it to be estimated using a number of criteria to evaluate tee-shot strategy.

Applying the Model at TPC Summerlin:

Impact of Lie/Angle:

The results of tee-shots must be adjusted based on the resulting lie and angle off-line from center that they come to rest. A drive six degrees off-line into the rough will roll a shorter distance than one that is hit down the middle of the fairway. Sometimes a driver hit into the rough or bunker will travel a shorter distance than a 3 wood hit into the fairway, just because it doesn’t roll 20-25 yards after landing. I adjust for angle/lie for each round through a linear process which shows the amount of yards that should be added or subtracted to the shot distance. The approximate equations used to derive these values are (where x = degrees off-line from center and y = adjustment value in yards):

Rough: y = -3x + 5
Intermediate: y = -4x + 9
Bunker: y = -6x + 19
Fairway: y = -0.3x + 3
Other (Desert, Out of bounds, Water, etc.): y = -13
Green-side Bunker: y = 5

Impact of Conditions:

Las Vegas is one of the highest altitudes (~2500 ft.) visited by the Tour during the year which increases the carry of drives by around 5%. My estimates say that driving distances were between 12-15 yards longer than at a normal Tour event, largely due to the elevation. I’ve also adjusted for the elevation (uphill or downhill shots) on individual holes. This amount varies between the extremes of the 2nd hole (downhill, adding 11 yards of distance) and the 3rd and 16th holes (uphill, subtracting 6 yards of distance).

Model Results for TPC Summerlin:

The chart below summarizes some basic results. I estimate players hit driver on between 68% and 71% of holes over the four rounds, roughly in line with normal expectations. They regularly hit something less than driver on six holes (1, 2, 6, 7, 10, and 15).

TEESHOTlasvegasNegative numbers indicate lower scores

Evaluating Decision Making Hole by Hole:

1st Hole – 408 yard Par 4:

Players hit driver here about 56% of the time. The fairway is narrow, with trees on both sides of the normal landing area. There’s only one fairway bunker to fear at around 295 yards to the right. This hole had the largest gap between the percentage of drivers hit by long hitters and short hitters with long hitters hitting driver only 40% of the time vs. 74% for shorter hitters. Long hitters performed roughly similarly with 3 wood or driver, while shorter hitters saw slightly better results from hitting driver.

2nd Hole – 469 yard Par 4:

This is a long downhill tee-shot over desert to a wide fairway. Two bunkers catch long shots while the desert can capture shots hit too far right. About 67% of players hit driver here, split as normal for a par 4, with longer hitters hitting driver around 60% of the time and shorter ones around 80% of the time. The results showed longer hitters performed roughly equal with 3 wood or driver, while shorter hitters performed slightly better with driver.

6th Hole – 430 yard Par 4:

Players hit driver around 62% of the time. This hole requires a slightly uphill tee-shot to a sinuous, narrow fairway with desert in play on both sides. Long hitters were cautious here, pulling driver only 40% of the time vs. 70% for shorter hitters. Long hitters performed slightly worse with driver, while shorter hitters performed equally well with either club.

7th Hole – 382 yard Par 4:

This hole requires either a lay-up to a narrow fairway (leaving ~125 yard approach) or a longer shot to a landing area surrounded by bunkers (leaving ~80 yard approach). Few long hitters took on the risky shot (8%), though players who hit driver performed no worse than those who hit hybrids/5 woods/irons. Driver was the worse play for shorter hitters (25%). Overall driver was hit around 14% of the time.

10th Hole – 420 yard Par 4:

There’s a bunker at around 295 yards on the left right where the fairway narrows from 33 yards to 18 yards. Players hit driver here half the time, with the long hitters hitting driver only 28% of the time vs. 59% for shorter players. Long players were best when they hit a lay-up with an iron/hybrid/5 wood, while 3 wood was the best option for shorter players.

15th Hole – Drivable Par 4:

Club selection here is solely based on what you need to drive the green because everyone chooses that option. At this altitude that means 3 wood for long hitters and driver for shorter hitters.

Player Decision Making:

In general over full-seasons, golfers who hit driver shorter distances hit driver more often than those who hit for longer distance. The longest players hit driver around 55% vs. around 85% for the shortest players. Keep that in mind when evaluating players below. Often times it would be a bad strategic decision for a very long hitter to hit driver, while a shorter hitter can comfortably hit driver on the same hole.

More Drivers Hit:

I estimate Nick Taylor, Colt Knost, and Troy Merritt all hit driver on almost every possible hole (87%+ drivers). None of those guys are long hitters at all, indicating that they were likely very aggressive off the tee. Runner-up Kevin Streelman also hit a lot of drivers (79%). He’s about average in terms of driving distance ability, though he’s one of the most aggressive players in hitting driver normally. When you drive it well for a week that pays off; Streelman gained 0.7 strokes/round on the field driving in his win at the Travelers and 0.5 strokes/round on the field this week.

Fewer Drivers Hit:

After playing very aggressive off the tee at the Frys last week, Brooks Koepka reined it in this week. He was one of the most cautious off the tee last year and was fairly cautious again this week. Hudson Swafford was a lay-up machine again; that fits what he did last week and his strategy from last year. Among the rookies, Tony Finau has impressed me the most with his tee-shot/approach shot game. He’s has the potential to bomb it off the tee, but has held back – like most long hitters – through the first two events.


Tee-shot Strategy at the Open

Choosing which club to hit on par 4/5 tee-shots is one of the major strategic decisions a pro faces on a hole. Hitting driver is regularly worth an extra 30 yards of distance, but shots hit with driver are on average hit further off-target than shorter clubs. This introduces larger risk of hitting into the rough, fairway bunkers, or OOB, and the larger carry of the driver takes moderate misses and compounds the damage. On most holes there isn’t much risk of a catastrophic miss (water or OOB) and the value of the extra distance with driver easily makes up for the slightly larger chance of ending up in the rough or a fairway bunker. However, on certain holes the safe zone (width between water/OOB/trees on one side and water/OOB/trees on the other side is more narrow, increasing the likelihood of a catastrophic miss. On other holes the fairway narrows dramatically in driver range and it becomes much more likely that a player will hit into the rough or a fairway bunker with driver – negating the extra distance. In both cases players regularly hit 3 wood, 5 wood, hybrids, or long irons off the tee.

To properly evaluate club selection strategy you have to know how golfers performed in general on each hole depending on whether they chose driver or a lay-up. However, no one tracks club selection and even collecting that data from broadcasts is an impossible task (were one even inclined to manually charting) because broadcasters show par 4/5 tee-shots less than any other type of shot. To address this I developed a model that estimates the probability that a player hit driver, 3 wood, or a shorter club based on 1) the distance of the shot (300+ yards almost always means driver; <250 yards means a lay-up), 2) location of the shot after tee-shot (the fairway adds a few yards, rough/bunkers subtract a few yards), 3) angle off-line the shot is hit (larger misses travel shorter than shots down the middle), 4) golf course conditions (general altitude of the course, specific elevation of the hole, firmness of fairways, atmospheric considerations, etc.), and 5) player driving distance ability (represented by their driving distance stats).

Applying the Model to the Open:

Impact of Lie/Angle:

The graph below shows a general model to adjust distance based on lie. This is important because tee-shots that are flown into fairway bunkers/rough generally roll shorter distances than tee-shots that might roll along the fairway before settling into the rough or a fairway bunker. In general, the roll portion of a tee-shot represents about 20-25 yards of distance. This evaluates the distance gained/lost relative to others on that hole based on the lie (rough/intermediate/bunker/fairway) and the degrees off-line from the center of the fairway. The graph is specific to the 1st Round at the Frys.


Impact of Conditions:

Silverado CC is located near sea level which eliminates any impact due to altitude. Certain holes are slightly uphill or downhill, so I’ve adjusted those holes to add or subtract distance. The impact is largest on the 3rd hole (uphill tee-shot subtracts roughly 6 yards of distance) and the 9th hole (downhill tee-shot adds roughly 10 yards of distance). The course conditions varied throughout the week. I estimate the first three rounds were played in conditions slightly drier than average (adding roughly 1-2 yards per tee-shot) while the conditions in the final round were much drier (adding roughly 5 yards per tee-shot).

Player Ability:

The most important factor is how far each player can hit driver. That’s estimated fairly well for regular Tour players through their measured driving distance. I used that for both returning PGA Tour and for returning players (with an adjustment to correct for longer courses played). For the few players without that data I used PGA Tour average driving distance of 289 yards. I estimated that each player hits 3 wood approximately 30 yards shorter than driver – which is consistent with player estimates and Trackman data. Obviously not all players carry a 3 wood, but it works as a general approximation.

Model Results for Open:

The chart below summarizes the basic results. Players hit driver between 63% and 71% of the holes and regularly chose something shorter than driver on five holes. This is slightly less than PGA Tour average where driver is hit around 70% of holes.

Click to Enlarge

Evaluating Decision Making Hole by Hole:

I evaluate the decision to hit driver or a shorter club based on the position after the approach shot. This method considers the distance from the pin and lie after the 2nd shot on a par 4 and par 5 in terms of average strokes remaining to hole out from that position.

4th Hole (407 yard par 4):

Players roughly split for the week between driver and a shorter club. Many were wary of the fairway bunker down the right side between 270-300 yards, choosing to hit 3 wood instead. The fairway also narrows from around 38 yards to around 28 yards after 270 yards. The advantage to hitting driver was consistently around 0.1 strokes better performance in all four rounds.

8th Hole (366 yard par 4):

Few players hit driver on this hole, maxing out at 25% in Round 4. This is a short par 4 where the fairway narrows considerably at driver length. Overall, those hitting driver here played about 0.06 strokes better across all four rounds, though all of that over-performance relative to shorter clubs was in the 2nd round. I’m still unsure to what level driver vs. shorter club performance is repeatable between rounds.

12th Hole (391 yard par 4):

Around 40% of players hit driver on this hole, consistent throughout all four rounds. There are two fairway bunkers here – one ending at 250 yards and one beginning around 280 yards. The fairway narrows from 38 yards to 28 yards at the second bunker, and to the right is out of bounds. Players hitting driver were slightly advantaged by 0.08 strokes throughout all four rounds.

14th Hole (422 yard par 4):

Around 40% of players hit driver here, also consistent throughout all four rounds. The concern here is a fairway bunker right at around 265-290 yards off the tee. Players who hit driver were slightly advantaged here to the tune of 0.06 strokes over four rounds.

17th Hole (375 yard par 4):

This hole played as a drivable (~300 yard) hole in Round 3. 33% of players hit driver over the four rounds – 42% in the 3rd Round. The landing area for a driver is dominated by a fairway bunker left. A bad miss left ends up in the bunker or trees, while a bad miss right could end up behind a tree. The pin positions in the 1st & 2nd Rounds also required an accurate approach to miss the pot bunker just short of the green.The 3rd Round was the only round where there was an advantage to using driver (0.17 strokes), which makes sense because the benefit of hitting the green off the tee on a par 4 is an almost assured birdie. The other rounds showed an advantage to laying-up with 3 wood or shorter.

Estimating Player Decision-making:

I haven’t evaluated the player by player results against reality, so these are absolutely estimates. In general, shorter players hit driver more often. This is because 1) they need to hit driver to keep up with the field, 2) because when they hit driver they can avoid many of the bunkers/narrowed fairways that are set-up to capture longer shots, and 3) because their bad side-to-side misses will travel shorter and into less dangerous positions. You can see this based on the difference between a player’s measured driving distance and driving distance on all shots. Shorter players have less of a gap, indicating fewer non-driver shots.

More Drivers Hit:

Jerry Kelly, Tim Clark, and Jon Curran (all very short off the tee) were the three leaders in % of drivers hit at above 85%. Matt Kuchar (slightly shorter than average) also was aggressive off the tee hitting driver an estimated 84% of the time. This fits prior data; Kuchar is normally quite aggressive off the tee, which compensates for his shorter overall driving ability. Last year, Brooks Koepka had one of the largest gaps between measured and actual driving distance (17 yards), indicating he laid-up off often off the tee despite being one of the longest hitters on Tour. He was extremely aggressive this week – 9th in % drivers hit at 79%. The winner, Sang-Moon Bae, finished 14th in % of drivers hit at 75%.

Fewer Drivers Hit:

Tyrone van Aswegen finished last in % of drivers hit with only 44%. Of notable players, Marc Leishman, Graham DeLaet, Jimmy Walker, and Hideki Matsuyama were all in the bottom 15 of players that made the cut (less than 55% drivers). DeLaet opted against driver more often than most last year. Jason Kokrak was the most likely of the very long hitters last season to lay-up (56% approximately) and he hit driver only 56% of the time this week.


Predicting Putting Performance by Distance

Mark Broadie’s research of the Shot Link data established a clear relationship between putt distance and % of putts made. PGA Tour pros make a very high percentage of their close putts, but only about half of their putts around 10 feet and only around one in six around 20 feet. Pros hole very few (~5%) of their longest efforts from 25 feet and beyond. That data on % of putts made for each distance now forms the backbone of the PGA Tour’s Strokes Gained Putting statistic where players are credited and debited for making or missing every putt from every distance. Over a single season Strokes Gained Putting is often an unreliable indicator of putting performance, particularly at the extremes and also for players who have putted much worse or much better than in previous seasons.

Putting performance is polluted by randomness; Tour players just don’t attempt enough putts over the course of the season to get an accurate picture of their underlying putting ability. However, to make accurate projections of putting ability, you need to know whether Graeme McDowell’s 0.9 putts gained this season represents more talent or more luck. I’ve broken down putting performance into four different distance buckets from the PGA Tour data: putts inside 5 feet, 5-15 footers, 15-25 footers, and putts outside 25 feet. The results show that putting performance is far more predictable and consistent at the short distances. Long putting is so noisy that it’s difficult to say anyone gains much of an advantage from their long putting over the long-term.

Inside 5 Feet:

These putts are almost always converted (average 96%). The spread in performance between 2011-14 was 93% to 99%. The spread in expected performance derived from weighting the previous four seasons is 94.3% to 97.8%. This indicates that we should expect every regular Tour player’s true talent from inside 5 feet to fall somewhere inside that 3.5% range. Based on an average of over 900 putts attempted inside 5 feet over a season, we should expect every regular Tour player’s talent in terms of putts gained or lost to fall between +0.2/round and -0.3/round.

The graph below shows the correlation between a three year average (2011-13) and 2014 performance for all players with qualifying rounds in all four seasons. The correlation (R=0.56) between prior performance and 2014 performance is strongest in this distance range.


5-15 foot Putts:

This length is either short birdie putts or par putts after a scrambling shot that are converted approximately half the time. The spread in performance between 2011-14 was 36% to 54%. The spread in expected performance derived from weighting the previous four seasons is 40% to 52%. Based on around 450 putts attempted from 5-15 feet over a season, we should expect every regular Tour player’s talent in terms of putts gained or lost to fall between +0.4/round and and -0.5/round. Compare that to the best putters on Tour gaining about 0.75 putts/round.

The correlation between three year average and 2014 performance is below. The correlation (R=0.53) is similar to that for the short <5 foot putts.

5-15 footers

15-25 foot Putts:

These length are normally longer birdies putts and are converted about 16% of the time. The spread in performance between 2011-14 was 8% to 26%. The spread in expected performance derived from weighting the previous four seasons is 12% to 20%. Based on around 225 putts attempted from 15-25 feet over a season, we should expect every regular Tour player’s talent in terms of putts gained or lost to fall between +0.15/round and and -0.15/round. There’s much less at stake from this range than the previous two, just because so few putts are attempted from 15-25 feet.

The correlation between three year average and 2014 performance is below. There’s not much of a relationship (R=0.28), showing that putting performance from this range is much more affected by random chance over a full season than the shorter length putts.

15-25 footers

Putts outside 25 feet:

These length are the longest birdie putts, often really lag putts just to get it close for par. The spread in performance between 2011-14 was 2% to 13%. The spread in expected performance derived from weighting the previous four seasons is 4% to 9%. Based on around 300 putts attempted from beyond 25 feet over a season, we should expect every regular Tour player’s talent in terms of putts gained or lost to fall between +0.1/round and and -0.1/round. Again, there’s very little difference in expected performance from this distance. Even the very best long putter on Tour will gain little from these putts – over the long term.

The correlation between three year average and 2014 performance is below. There’s almost no relationship (R=0.10), which means it’s almost impossible to predict how well a player will putt on these long putts. The top ten long putters from 2011-13 average hitting 7.6% of their putts (versus 5.5% average). They only hit 6.7% of their putts in 2014 – a regression of almost 50% to the mean.


The Big Picture:

This graph shows performance in all four ranges. The longer putts show little relationship to future performance, while the shorter putts do show a more consistent relationship. This means that players who gained a lot of putts last season based off their longer putts will start making putts at a lower rate, while those who gained a lot of putts based on shorter putts are better bets to retain that putting ability.


Most Improved Putters from 5-15 feet in 2014:

1. Graeme McDowell

2. Charley Hoffman

3. Billy Horschel

4. Justin Leonard

5. Michael Thompson

These guys have a better chance of retaining their putting performance into 2015.

Most Improved Putters from > 25 feet in 2014:

1. Rory McIlroy

2. Y.E. Yang

3. David Toms

4. Brendan Steele

5. Brian Gay

These guys look likely to regress in terms of putting performance, especially McIlroy who performed to career average on all other putts, but hit 8% more of his long putts – gaining almost a third of a putt per round over his career average.

Top Twenty Golfers for 2015

This three week break between seasons doesn’t provide for a lot of time to digest the 2013-14 PGA Tour season and preview the 2014-15 season. I’m still digging through the data from last year, trying to highlight which players took genuine steps forward, who’s stats are throwing up red flags, etc. However, these are my top twenty golfers for next season. The criteria is a bit murky, but it’s basically the twenty guys who will make the largest on-course impact on Tour – whether it’s cashing checks, winning tournaments, or even winning majors. Most of these guys are obvious (it’s no secret that Rory is a beast), but maybe a few won’t be so intuitive.

Honorable Mentions:

Luke Donald’s fall from grace this season was unexpected, but he both regressed sharply in his long game (tee shots/approach shots), but also slumped with the putter over the last half of the season. Guys who fall off sharply in their long games tend not to rebound much the next year. Kevin Na finally had his break-out season and no one seemed to notice. After an injury riddled 2013, Na came back with the 17th best season on Tour – all because of a huge improvement off the tee and with his irons. Billy Horschel’s end of the season FedEx run was awesome. He was my last cut from the list, mostly because I want to see how he deals with being the guy with the target on his back this year. Chris Kirk had a bit of a break-out season as well, winning the McGladrey early and the Deutsche Bank late. It looks like a lot of his success was more of a putting surge than anything. My numbers still love Steve Stricker, but he’s going to be 48 and his long game cratered this year. He’ll still pop up a few times this year, but his run at the top is done. I could write a whole post on why I think Phil Mickelson is done as an elite player, but the below chart sums it up pretty well. His tee to green game has been in terminal decline for years, covered up by miraculous putting in 2012-13. He’s just so reliant on his short game/putting these days that it’s hard to see him contending that often.


#20 – Hideki Matsuyama

Matsuyama’s first full season on Tour was an obvious success. After a mixed bag in the opening few months (a pair of top tens to go with three injury W/Ds), Matsuyama broke through with his first victory in a playoff at the Memorial. At only 22, he’s already proven himself as one of the ten best ball-strikers on Tour – particularly on the short/medium approach shots. His putting was disappointing – 156th in SG Putting and pretty terrible on the short putts that really show off a golfer’s true talent – but that’s his only weakness. Perhaps most importantly his two year exemption from winning the Memorial means he’ll be able to compete this season without any pressure to retain his card.

#19 – Jimmy Walker

2013-14 was his true break-out, winning three times and earning a spot on the Ryder Cup team where he was one of the only Americans to impress. Walker’s early season run was built on wildly unsustainable putting success, and he regressed sharply to his career averages as the season went on. However his tee to green game got even better after his third win; even though he putted worse than PGA Tour average down the stretch, he still earned two top tens and finished T26 or better in six of seven events. He’s the prototype of a long, but wild hitter off the tee. His emergence the past two seasons has been down to his vastly improved iron play. It’s really unlikely he has anything like the success on 2013-14, but another trip to the Tour Championship and a Presidents Cup spot wouldn’t be surprising at all.

#18 – Zach Johnson

Zach Johnson really fell off the radar this year. His only win came at Kapalua in January when no one is paying attention, then suddenly he was playing in the Ryder Cup. The culprit for Zach this year was just not making putts. He’s been one of the best putters on Tour for years, but slumped this year. I have no doubt he’ll putt better this season and if he does I expect we’ll hear from him a bit more often because his tee to green game was as sharp as ever last year.

#17 – Graeme McDowell

G-Mac benefited the most last season from a lucky and/or much improved putter. His career SG Putting was around average entering the season, but he finished #1 on Tour in SG Putting by the end of the season. Everything I’ve ever researched regarding changes in putting performance suggest he’s going to regress sharply next season. However, McDowell was already consistently excellent at long putts, and his improvement was almost entirely in putts inside 15 feet – the kind of putts where talent shows more strongly over a season. Long story short, G-Mac’s putting improved a lot, but I think he has a good shot at retaining a lot of that improvement and really establishing himself as an above-average putter.

#16 – Keegan Bradley

I think there was a lot of sense this year that Keegan Bradley wasn’t living up to expectations. He was consistently strong all season, but never really contended in a major event and missed the cut at the Masters, PGA, and Players. All in all though, he was a solid top 20 player on Tour – he just missed out on the wins. I expect he’ll find a win this year and earn his way into the Tour Championship without much problem.

#15 – Charl Schwartzel

Schwartzel was another guy that just wasn’t on the Tour’s radar at all this year. He delivered the kind of elite tee to green performances that it takes to win at the Memorial and WGC-Bridgestone, but the putter let him down both weeks. He’s always really strong tee to green, especially with his irons. Predicting a win is always tough – especially for guys like Schwartzel who always play strong fields – but no one should be surprised if Schwartzel wins this year.

#14 – Henrik Stenson

After last summer/fall’s run where Stenson won both the PGA Tour’s FedEx Cup and the European Tour’s Race to Dubai, he still managed to record one of the best seasons on Tour, though without a win this year. Stenson’s game is built around long, accurate driving – he’s one of the top five on Tour off the tee – and is great with his irons as well. His length and accuracy also give him the green light to attack most par 5 greens in two, making him one of the more aggressive players on Tour. His only flaw is his putting; it likely cost him a win at Bay Hill this year.

#13 – Jordan Spieth

There were few guys in the world getting better results over the first half of the season than Spieth. By the time he finished 2nd at the Players, he had six top tens in fourteen starts and had contended down the stretch at two huge tournaments. He didn’t play awful in the second half, but he struggled off the tee and his approach shots weren’t that great. Struggles in those long game components tend to stick around for awhile, so priority #1 for Spieth has to be getting his tee to green game squared away. His short game and putting were really solid again this year, so no problems on that front. I’m going to regret ranking him here if he gets his long game squared away because he was a legit top five in the world player early in 2014.

#12 – Tiger Woods

Now we get to the biggest question mark of the season, how will Tiger return? I think there’s some sense that Tiger wasn’t a stud in 2012-13 because he didn’t win a major (we forget he had three top tens in eight tries in majors). Based off that and how terrible he was when injured this year, people are expecting the worst for Tiger next year. I’ve even weighed him from an analytics perspective and highlighted how aging is going to prove his highest hurdle in the coming years. Let there be no question that Tiger has shown the ability since 2009 to be the best golfer in the world. Between 2012-13, after he got healthy and adopted his new swing under Foley, he was the best golfer in the world. He won eight times on Tour – including against strong fields at the Players and WGC events – and posted the best scoring average relative to the field over those two seasons.

The question is whether he can get healthy again. He’s missed significant time due to these nagging injuries twice now in the last four seasons. If he can get as healthy as he was in 2012-13, I expect him to play to the level of no worse than 2nd best in the world. That means 2-3 wins and contending consistently. I think it’s unlikely he ever returns best in the world, simply because Rory has been essentially equal to him the last few years and aging from the late 30s on saps a lot of golfers’s performance. And he’s not going to equal or best Jack’s record unless he has a lengthy run of healthy seasons.

#11 – Bubba Watson

Bubba was nuclear hot early in the season – 2nd in Phoenix, win at Riviera, 2nd at Doral, and win at Augusta. Later on, he was an errant drive away from likely winning the Memorial and his tee to green game was dominant enough to win at the BMW Championship, but he couldn’t make a putt all weekend. I still think there’s some sense around the Tour that Bubba’s driving makes him a one trick pony. That might have been fair in 2010, but he’s improved his short game and putting so that they’re not dragging him down, and his irons are good enough. He’s also much less wild than normally perceived – he was about average in hitting fairways this year and cut his number of Other drives (tee shots that land out of bounds, in the water, or in the trees) down to nearly Tour average this year. His ability to out-hit the field will always make him deadly on Augusta’s comically wide fairways, but he performed great at the Memorial this year and that course probably has the toughest rough of the normal Tour season.

#10 – Dustin Johnson

Suspension or “leave of absence” aside, Dustin Johnson was having his best season as a pro in 2014. He beat a great field in China to start the season before some near misses to Jimmy Walker (Pebble Beach), Bubba (at Riviera), and Patrick Reed (Doral). He only missed three cuts all year and had high finishes at both the US Open and Open Championship. Assuming he comes back healthy and focused from this sabbatical, there’s no reason why he can’t continue to play at a top ten level. His hypothetical six month suspension expires just before the Tour heads to Pebble Beach – the course he’s had both his most professional success and worst professional moment.

#9 – Bill Haas

I’ve written fondly about Haas’s game quite a bit the last few months. His performance this year was nearly flawless, with only a W/D at the Heritage to mar 27 made cuts in 28 starts. Haas isn’t just making cuts either; he had five top tens and seventeen top 25s. Inexplicably left off the Ryder Cup team, Haas figures to be a sure bet to make the 2015 Presidents Cup squad with another similar season. Despite winning five times in the last five years and taking home the FedEx Cup, there are still people sleeping on Haas as an elite player. He earned just over $2.8 million last year and I’d peg him as extremely likely to eclipse that total if he stays healthy this year.

#8 – Rickie Fowler

After the start to the season Rickie Fowler had – five missed cuts by March and only a 3rd at Match Play – people were obviously way down on him. He and Butch Harmon had changed his swing and his game was a mess, especially the putting. Starting with the US Open though, his swing clicked and he started to hole nearly every putt, and only Rory and Furyk were better from June to September. He’ll be lucky to ever putt that well over a few months, but his tee to green game really improved over previous seasons. He’s at a level right now where he’ll be a stud even when the putting regresses to normal.

#7 – Jim Furyk

I’ve written at least half a dozen posts about aging this year, and with each one I marvel a little more at what Jim Furyk has been able to accomplish. Ignore that he hasn’t won in four seasons; this guy is as good now as he was ten years ago and just had his best season since his mid thirties. He continues to churn out top ten tee to green seasons. His game is just perfectly calibrated to hit fairways, hit greens, and scramble in the rare case he misses one. He had four seconds this year! At 45! I think he’ll fall off a bit this year, but he’s still going to be a huge factor every week.

#6 – Matt Kuchar

Kuchar’s season can be summed up in two hole-outs. First, he lost in Houston when Matt Jones holed out to win their sudden death playoff. Kuchar then holed out to win the Heritage two weeks later. Kuchar never seriously contended for the rest of the season (though he added four more top tens – 11 for the season). Only Jason Day has a better all-around game; Kuchar’s solid off the tee, hits his irons well, and his short game is good. He really shines with the putter, where he’s around the top ten on Tour consistently. In terms of week-to-week earnings, Kuchar’s as solid as anyone on this list but McIlroy because of how many starts he makes. One of these days he’s going to run into a major win or FedEx Cup.

#5 – Jason Day

Given the thumb injury Day was suffering through for almost the entire PGA Tour season, it’s remarkable he was able to have so much success. Day ended up top twenty on Tour tee to green, despite that injured digit, and turned in another great putting season. Fully healthy, there’s no doubt Day is going to improve off the tee and with his irons, and his short game is already ridiculously good. Add in that he’s a legitimately great putter and there’s not much doubt that Day’s going to be a stud in 2015. He’s consistently been a monster in majors, so it’s a question of when, not if, he’s going to win one.

#4 – Sergio Garcia

Sergio went winless on Tour this year, an amazing fact since he played two of the ten best tournaments of the season relative to the field. Unfortunately, Rory McIlroy beat him both times (Open Championship and WGC-Bridgestone). This was a textbook Sergio season; he was one of the best in the world with his irons and continued his recent success with the putter. If there’s ever a season where he’ll win a major, 2015 looks like the ideal one. Sergio has always been strong at the links set-ups, and this year the majors visit three links style courses. Sergio is as good a pick as any to win one of them.

#3 – Justin Rose

There’s really not much to say about Rose. He’s simply one of the best ball-strikers in the world and has emerged the past few seasons as one of the best players in the world. This year might’ve seemed like a bit of a disappointment after the US Open win in 2013, but he won twice (at Congressional and the Scottish Open) and dominated at the Ryder Cup. Like the guys right above and below him on this list, he’s right in the middle of his prime and playing great. He’s a threat to win any time he can string together four above-average rounds with the putter.

#2 – Adam Scott

In the rush to anoint Rory as The Best in The World (and he is), everyone missed the season Adam Scott put together. He only won once (Colonial), but his worst finish this year was T38 at the Players and he didn’t fall below T16 after that. Early in the year he rode a hot putter, but when that cooled down down the stretch he was still stockpiling top tens. He has a top five long game in the world, and has shown the past few years that he can be just average with the putter. This year he’ll likely start experimenting with some modified putting technique because his method of anchoring will be illegal in 2016, but I doubt he’ll face any long term trouble from that. More importantly, he’s coming off a dominant three year stretch where only Rory and Tiger have hit higher heights and he’s smack in the middle of his prime. Another major title and multiple wins should be the goal this year.

#1 – Rory McIlroy

Rory had a season for the record books. The best season by my ratings since Tiger Woods in 2009, the best driving season in the Shot Link era, two major wins, and two more victories in huge events. Most importantly, he absolutely killed the narrative that he can’t hold onto a lead – he responded to blowing great first rounds at the Memorial and Scottish Open by pulling away from the field in the 2nd round at the Open Championship. His combo of distance and accuracy is ridiculous; he not only can outhit the field by 20+ yards every time, but during his run in July-September he almost never lost a drive out of bounds or in the water. Typically the long hitters are restrained by that inaccuracy, but Rory knows he’s going to be able to keep those 310 yard bombs in play.

The rest of his game was great this year. When you’re gaining over a stroke on the field just off the tee, you can afford an average short game. His irons were top ten on Tour, which is just unfair. And I’ve written about his putting. It’s impossible to putt as well as he did in July-August long-term. What he did in the FedEx Playoffs when he was essentially Tour average is much more indicative of his long-term putting abilities. That’s fine, but it’s what separates him from ~2000 or 2005-08 Tiger Woods. That version of Tiger was the best in the world tee to green, but also was one of the best putters in the world. Rory still has time to work on his putting and get to that level, but all of his putting improvement this year was on long putts. Performance on long putts is extremely noisy even over multi-year samples. Despite all that, Rory enters every tournament as the favorite from now on.

Best and Worst of 2013-14 PGA Tour

Best rounds:

In strokes, adjusted for the ability of the field and the difficulty of the course that day.

1. Brendon de Jonge, 2nd Round Wells Fargo Championship

de Jonge shot a 62 when the course played to 72.4 and the field was solidly PGA Tour average. Unfortunately it followed a 1st round 80. He made the cut, shot two sub 70 rounds on the weekend, and captured one of only two top tens of his season.

2. Adam Scott, 1st Round Arnold Palmer Invitational

I remember tweeting after this round that it was the best of the season so far and it held up for another two months. Scott shot a 62 when the field played to 71.8 and was a bit above-average. Scott would hold the lead for most of the rest of the tournament until he blew-up with a 76 in the final round to finish solo 3rd. Scott would get his only win of the season two months later at the Colonial – beginning a ten tournament streak where he finished top 20 in every event and top ten in seven of them. His season remains ridiculously underrated.

3. Sergio Garcia, 2nd Round WGC-Bridgestone

This is the round that propelled Sergio into the lead and set-up Rory’s Sunday comeback to secure his 2nd of three wins over ridiculously strong fields. Sergio’s 61 bested the field by nine strokes, but the Bridgestone field was the fourth strongest of the year which boosts him a lot.

4. Troy Matteson, 2nd Round Greenbrier Classic

I have no recollection of this round and no recollection of ever seeing Matteson’s name this year. He sandwiched this 61 (field average of 70.9) between three others which were below average and finished T45.

5. Rory McIlroy, 1st Round Memorial

Some wonderful soul uploaded this round (along with Adam Scott & Jason Day) to Youtube. Rory’s 63 when a strong field played to 72.2 put him in the lead by three strokes, but he followed it up with a 78 on Friday and faded to T15 over the weekend. Remember the narrative that Rory couldn’t follow-up good first rounds? He blew this lead and one at the Scottish Open in July, but then followed up a 1st Round 66 at the Open Championship with an even better (relatively speaking) 66 to solidify his lead. I’d say he’s killed that narrative.

Honorable Mentions:

I can’t help but mention Andres Romero’s 1st Round at the Las Vegas event – the 25th best of the season. He opened with a 61 when the field averaged 69.5 (amazingly this was also the day J.J. Henry shot a 60). Much more notable is his 2nd Round 81 (!). His 81 was eleven shots worse than the field (the worst round by far that anyone among the top 100 rounds shot in the same tournament). He unbelievably ended up missing the cut by two strokes, making this the only one of the best 200 rounds this year where the player missed the cut.

George McNeill’s final round 61 at the Greenbrier, played right after he found out of his sister’s death, was the 15th best of the season. He finished two back of Angel Cabrera ultimately, but cheers to that round.

Worst Rounds:

I’m ignoring anyone who doesn’t at least pretend to compete regularly. #1 may or may not meet that criteria.

1. John Daly, 2nd Round at Innisbrook (Valspar Championship) – 90 when the field played to 72.7

2. Matt Every, 3rd Round at the Deutsche Bank – 86

3. Michael Bradley, 1st Round at John Deere Classic – 84

4. Toru Taniguchi, 3rd Round at US Open – 88 on the hardest day at Pinehurst

5. David Duval, 2nd Round at Travelers – 83

Honorable Mentions:

Bubba Watson’s allergy marred 1st round at the Arnold Palmer Invitational was 10th worst by a touring professional. He withdrew, unsurprisingly. Both Paul Stankowski and David Duval shot 81 in the first round of the John Deere Classic, giving that round three of the worst thirteen results of the season. Duval withdrew, but Stankowski saw out the second round with a 78 – the worst first two rounds of the season among touring pros.

Best Tournaments:

1. Martin Kaymer – US Open

2. Dustin Johnson – WGC-HSBC

3. Rory McIlroy – Open Championship

4. Rory McIlroy – WGC-Bridgestone

5. Rory McIlroy – PGA Championship

Rory had himself quite the run late summer.

Honorable Mentions:

Sergio had the 7th and 10th best tournaments of the season, back to back, but lost to Rory both times (Open Championship and WGC-Bridgestone). All four major winners were in the top fifteen (Bubba’s Masters win was 14th). Webb Simpson’s -24 win in Las Vegas (6th best) came against a poor field and on one of the easiest courses, but he torched the field to win by six shots.

Best Expected Performances:

This is based off my expected performance ratings which project every pro in my database every week. It gives you an idea not only who was the best player, but when they were the best. I’ll just mention the best guys once.

1. Rory McIlroy entering the Barclays

Unsurprisingly the best player’s peak came after his three straight victories. He also holds the next five spots – three in the other FedEx Cup events and the others at the PGA and Memorial. Safe to say he was best in August/September.

7. Adam Scott entering the Tour Championship

Remember that insane ten event run I mentioned earlier? This was the culmination of his season, and he played to expectation to finish T9.

15. Tiger Woods entering the event at Torrey Pines

After being the best in the world over 2012-13, Tiger entered 2014 at the top of my ratings. This was his first event, a T80 that resulted in a MDF. He followed with a T41 in Dubai a week later. Things unraveled from there, but this was when he was supposedly at his peak.

23. Sergio Garcia entering the PGA Championship

After being so unlucky to play amazing and lose in his previous two events, Sergio entered the PGA in his best form of the year. He never really threatened however.

27. Justin Rose entering the Barclays

Another guy who didn’t get much attention this year, despite shipping two quality events (at Congressional and the Scottish Open).

Most Unlikely Performances:

These are the tournament performances that were furthest away from my expectations in the positive direction.

1. Mike Weir at the Byron Nelson

Weir was a fringe elite player for most of the 2000s, but inexplicably lost his game around 2011. He’s less awful than he was around 2011-12, but was still projected around the level of an average Tour player in May. He finished solo second, two back of winner Brendon Todd. It was Weir’s only finish above T44 all season.

2. Martin Kaymer at the US Open

This is unsurprisingly seeing how it was the #1 performance overall above. Kaymer is a very good player, so this is less likely than McIlroy or Adam Scott playing this well, but the degree to which he destroyed that field on that course is awesome.

3. Jim Renner at the Pebble Beach Pro-am

Jim Renner is thoroughly anonymous as a pro; he’s about Tour average, but played nearly well enough to win in February. He settled for a T2 with Dustin Johnson, one back of Jimmy Walker. This finish represented over 75% of his earnings for the season.

4. Tim Clark at the Canadian Open

Clark entered the final round three back of Jim Furyk. On what was the fifth easiest round on Tour all season, Clark shot a 65 to win by a stroke. Once a peripheral top 25 player around when he won the 2010 Players, Clark’s fallen on hard times. This season – with a win, 2nd, and 5th – represents a bit of a comeback.

5. Patrick Reed at the Humana

Despite winning in 2013, Reed entered 2014 rated as essentially an average PGA Tour player. His hot streak from the Humana onward cemented him as a Ryder Cupper. He started in Palm Springs with three straight 63s and held on to win by two.

Honorable Mentions:

Billy Horschel’s back-to-back wins ranked 29th and 33rd. Rory’s Open Championship win ranks 85th – right ahead of Phil’s T2 at the PGA Championship.

Measuring the Signal in First Round Performance

After the 1st Round of the Deutsche Bank Championship a month ago, Keegan Bradley sat two strokes off the lead. Playing in front of the home fans, Bradley fired a six under 65 fueled by great putting (4.2 strokes gained) and a solid long game (2.3 strokes gained on tee shots and approach shots). At that point he looked in great shape keep it going and capture his first win of the season. However, he came out the next three rounds and shot 71-69-71 to finish T16. The culprit wasn’t his long game either; he gained 1.6 strokes on the field per round in the second, third, and fourth rounds, good enough to finish in the top ten for the event in strokes gained off tee shots and approach shots. No, it was the putter that let him down. After being hot in the opening round, he actually lost 0.4 strokes per round from his putting.

My question is: how common is Bradley’s experience? When golfers come out in the 1st round and play/putt very well, how often do they keep playing/putting well? What about when they come out hitting the tee shots and approach shots well? Does that carry over to the next day? Many around the game act like one round of performance is really meaningful (just look at everyone who advocated for playing Jordan Spieth and Patrick Reed after their Friday morning 5&4 win at the Ryder Cup), but does first round performance tell us anything about how a player will perform in the following round?

Looking at Putting:

I gathered round by round Strokes Gained Putting data from the twelve most recent PGA Tour tournaments (Travelers Championship through the Tour Championship). First, I checked how 1st round putting performance predicted 2nd round putting performance. That’s the first graph below, and the results show how player putted in the 1st round hardly sheds any light on how they will putt in the 2nd round (R^2 of 0.001). In fact, someone who putted as well as Keegan Bradley did in the above mentioned round would be predicted only to putt 0.2 strokes above average the following round.

rd1SGP v rd2SGP

Next I generated prior expectations of Strokes Gained Putting performance from the past several years of data. I’ve shown before that putting performance isn’t very consistent season-to-season, so I’m using performance from 2011 to 2014 to generate the prior. The below graph shows how well the prior expectation predicted 2nd round putting. The results still were not highly predictive – R^2 of 0.01 (performance round to round is highly variable in golf) – but the regression line produced tracks pretty closely with results. Players predicted by the prior to putt well generally putted well and those predicted to putt poorly generally putted poorly.

priorSGP v Rd2SGP

Finally, I tied both pieces of information together. The prior estimate proved way more predictive than just 1st round performance, but does 1st round performance have any information to add? I set-up a linear regression with the prior estimate as x1 and the 1st round performance as x2. The results indicated 1st round putting performance provides no extra information to predict 2nd round putting performance (the coefficient was indistinguishable from zero). If you have a good guess of how well a player will putt, you can safely ignore first round putting performance.

Looking at Long Game Performance:

The long game is tee shots and approach shots (drivers/woods/irons essentially). I gathered long game performance data from the same twelve PGA Tour tournaments for the first and second rounds. I then ran the exact studies as above just substituting long game data for putting data. The correlation between 1st round long game performance and 2nd round long game performance was higher than with putting, but still didn’t contain a lot of information (R^2 of 0.03). If a player plays four strokes above field average in long game strokes gained, they’re expected to play 0.6 strokes better in the long game in the 2nd round.

rd1LONG vs rd2LONG

There was also a higher correlation between my prior estimate for long game ability and 2nd round long game performance (R^2 = 0.10). Again though, the regression line tracks closely with the results. Top ten long game players (around +1.2 strokes or above) generally performed to that level in the 2nd round.

priorLONG vs. rd2LONG

Tying both pieces together indicated that there is a small amount of signal in 1st round long game performance. Combining the prior estimate with 1st round performance slightly increases the fit of the model. The regression equation suggests that you should weight your prior estimate at twelve times the strength of first round performance. This indicates that someone who is PGA Tour average in long game shots, but produces an elite round of 4.0 long game strokes gained, should be expected to play about 0.3 strokes above average in long game shots. That seems like a small difference, but it’s enough of a shift in talent to move a player from around 50th best in the world to about 30th best in the world.

The Takeaway:

Based on these results, it looks like 1. a single round of performance is much less predictive than an estimate built on past-performance and 2. the small amount of signal contained in single rounds is from performance on tee shots and approach shots. Putting results from one round provide no more information than was available before the round. On the other hand, golfers who play particularly well on tee shots and approach shots in a round should perform slightly better than expected the following round.