Golf Analytics

How Golfers Win

Monthly Archives: July 2015

Expected Tournament Wins

I first discussed the concept of expected wins in my March article on Rickie Fowler over at NoLayingUp. Basically, I wanted to look at how often a certain level of performance on the PGA Tour results in a win. This way, there’s some sort of context neutral benchmark when we talk about why certain players are winning more or less than someone thinks they should. Rickie Fowler was the perfect introduction to this topic; he had been slammed for several years for only winning once on Tour, but when viewed through the lens of expected wins, Fowler had played some really good tournaments that would’ve normally resulted in wins, but others beat him. Of course, Fowler has gone on to win two high profile tournaments already this season

Calculation of Expected Wins

I gathered all PGA Tour tournaments (2010 to present) from the Official World Golf Rankings site, noting the winners and each player’s performance in strokes versus the field (also adjusted for strength of field so the US Open credits players for a harder field and Mayakoba debits their performance). I did the same for all European Tour tournaments over the same time period. I discarded all tournaments that did not reach four rounds and all players who missed the cut or withdrew.

I then performed a logistic regression of performance in strokes per round on the binomial variable of whether the player won the tournament or not. This produced the curves below for the PGA Tour and European Tour. I should note, I included all tournaments in each Tour’s data regardless of whether they were co-sponsored, alternate field, limited field, invitationals, or majors (majors and WGCs were included only in the PGA Tour dataset). However, this is supposed to measure how often a player should win in a typical event. Obviously the listed figure for win expectancy will be lower for majors and higher for alternate field or limited field events like the Tournament of Champions.

PGA Tour results

PGA_Tour_Win_ExpectancyIn a typical PGA Tour event, it’s extremely rare to win with a performance less than 3.0 strokes per round better than the field. However, increase to 4.0 strokes and a player is expected to win just over half of the time, while victory is nearly guaranteed at 5.0 strokes per round better than the field. In fact, only Louis Oosthuizen at the 2012 Deutsche Bank has exceeded 5.0 strokes per round without winning.

The best performance in a tournament between 2010 and 2015 was Rory McIlroy’s eight shot victory in the 2011 US Open where he beat the field by 5.7 strokes per round.

European Tour results

European_Tour_win_expectancyThe curve for the European Tour is broadly similar, but the 50/50 point is reached earlier – around 3.5 strokes per round – indicating the average European Tour event is won with a slightly less impressive performance. In fact, at around 4.0 strokes per round a player would be expected to win a typical European Tour event about 80% of the time versus 50% in a typical PGA Tour event.

The best European Tour tournament between 2010 and 2015 was Sergio Garcia’s eleven shot win at the 2011 Castello Masters.

Best Results from 2010 to 2015

bestperformances20102015Only PGA Tour or European Tour events from 2010 to present.

Applying to Rickie Fowler…again

What’s interesting about Rickie Fowler’s success this season is that both of his wins have come in big events with quality fields, but have required less impressive performances than normal. His Players Championship victory was actually slightly less impressive than his 2012 loss to Matt Kuchar, while his Scottish Open performance earlier this month rarely results in victory – even on the European Tour. In other words, after getting the short end of the results for the first few years of his career, Rickie’s gotten some good luck and has taken advantage of both opportunities to win this season. Below are Rickie’s ten best performances of 2010-15.

rickiefowlerperformances

British Open at Old Course Preview – 2015

Advantage of Long Hitters:
The Old Course is popularly seen as a strong spot for the guys who hit it longest, and the results from 2005 and 2010 bear that out. Every five yards greater than the field a player hit their average drive in all events was worth 0.15 strokes/round in 2005 and 0.30 strokes/round in 2010 beyond their normal level of performance. In other words, long hitters had a sizable advantage in each of the last two Opens contested at the Old Course.

As to why that advantage persists, longer driving distance is correlated with larger absolute misses off the tee. On regular courses, the danger off the tee increases as the miss gets larger as bunkers, rough, trees, etc. are brought further into play. Also, the danger is typically equally distributed with rough/trees/etc left and right. If you look at the Old Course (especially holes from #9 onward) there are pot bunkers spread across normal driving zones. A drive that misses slightly could catch one of the penal bunkers, while another that misses by more ends up in fine shape. Also, take a look at the danger off the tee; on a half-dozen or more holes it’s solely to the right. Certainly a left miss leaves a worse angle, but there’s no way that’s equivalent in penalty to the rough or bunkers right. In addition, holes like #1, #7, and #18 feature little danger off the tee at all. Distance also gives the ability to hit over bunkers on a number of holes.

The Old Course is also deceptively short. Although it’s listed at 7300 yards – roughly average for a PGA Tour course – it’s almost 300 yards shorter than you would expect if each hole was as long as its average par is on a PGA Tour course because of the unique fourteen par 4 layout. This would place it as one of the very shortest on the PGA Tour alongside Pebble Beach and others.

Par 4 Advantage:
That unique layout also gives an advantage to players who struggle with par 3s or par 5s. A great example is Hunter Mahan; Mahan has been awful on par 3s in recent seasons, a symptom of his overall struggles with his iron play. However, his great driving and putting has bailed him out and allowed him to score on the par 4s at a high level. This week sees three additional par 4s and two less par 3s than normal. Ian Poulter, Ryan Palmer, and Lee Westwood are others should see an advantage, while Dustin Johnson is the one notable who has really killed it on par 3/5s.

Travel and the John Deere/Scottish Open Debate:
A lot has been made over Jordan Spieth’s decision to play at (and win) the John Deere last season. Typically that event is skipped by most top players to allow them to either compete in the Scottish Open (as about a dozen or two PGA Tour players chose) or travel over to the UK at their leisure. I wrote up a piece on the impact of playing in the Scottish versus John Deere last year and I largely stand by the conclusions. US based players all suffer to some degree coming over – probably because of a mixture of the time zone and links golf – but players who compete in the John Deere under-perform their normal performance level significantly more than players who chose to play the Scottish Open.

As to whether this affects Spieth, obviously the most important factors affecting his performance this week will be random fluctuation in talent and the weather. I expect his play to be slightly degraded this week because he played the John Deere last week, but it’s far more likely catching the bad end of the draw weather-wise or missing a few putts will cost him the Claret Jug rather than the impact of travel/time change.

Links Experience/Performance:
A lot is made of past performance on links courses, but it’s important to remember just how few true links events are played each year. Since 2008, the Irish Open has been contested on links land three times and the Scottish Open five times. Add to that the once yearly playing of the British Open and the Alfred Dunhill Links and you get 24 events that were indisputably links golf. Perhaps a more liberal definition would include a course like Chambers Bay or Whistling Straits. Perhaps a few European Tour events played at seaside venues could be included as well, but overall you’re looking at 3-4 events per season.

Several players do stand out for their links performances though. All numbers here are relative to a normal performance level baseline of rounds played prior to the events in question. Of guys with at least 40 links rounds since 2008, Marc Warren, Shane Lowry, and Darren Clarke have fared best. Expanding to greater than 24 rounds, Rickie Fowler, Adam Scott, and Stewart Cink also emerge. No shockers there as all have contended for or won major links events. Major names who have struggled include Joost Luiten, Matt Kuchar, and Ian Poulter. Ideally we would look at more detailed markers of links success (creativity around the greens?, lag putting?, low approach shots?), but this general performance data will have to suffice for these purposes.