Golf Analytics

How Golfers Win

Performance Impact of Playing John Deere Classic vs. Scottish Open

The week before The Open Championship features a choice for the elite golfers on the PGA Tour; they can enter the John Deere Classic, a weak field PGA Tour event with the smallest purse of regular full-field events, they can take the week off to prepare for The Open Championship, or they can enter the Scottish Open, one of the premier European Tour events held on a links style course which exempts the OWGR top 60 – giving PGA Tour golfers a chance to play in Europe. This week, in addition to golfers who actually hold European Tour cards, Phil Mickelson, Rickie Fowler, Jimmy Walker, and several others all chose to tee it up in Scotland, while Jordan Spieth, Zach Johnson, Harris English, and most others entered the John Deere Classic.

The arguments in favor of entering the Scottish Open are two-fold in my eyes: first, you get to acclimate to the time difference a week before many of the other golfers, and second, you get to play a links style course rather than a typical PGA Tour layout which presumably better prepares you to play the following week. Phil Mickelson famously won the Scottish Open last summer, before winning his first Open Championship at Muirfield the next week. As a bonus the Scottish Open purse is the same size as the John Deere Classic (£3,000,000 vs. $4,500,000).

As to the advantages of playing in the John Deere? First you accumulate FedEx Cup points to either secure your card or bolster your chances of advancing further in the Playoffs. The PGA Tour awards no points for guys playing in Scotland. That obviously goes for the exemptions that come with winning the tournament as well. It’s possible that certain players couldn’t secure entrance to the Scottish Open, but it exempts the top 60 in the World Rankings. Spieth, Zach Johnson, English, Ryan Moore, Kevin Na, Chris Kirk, Kevin Streelman, and John Senden all could’ve entered but chose to play in Illinois. As a bonus, the John Deere provides a Sunday night charter that transports golfers from Illinois to Britain.

When I tested my assumptions that playing the Scottish Open the week before was an advantage my results indicated that golfers who played in Scotland rather than Illinois the week before enjoyed a significant advantage relative to those who played in the John Deere. I’ll explain my process and results below.

First I gathered the results of the last six Open Championships that I had handy for another project. I then found basic performance expectations for each golfer with results based on their prior performances (basically using results from the two years prior to each Open). That gave me results to compare and a baseline of expectations. If players significantly over or underperformed that baseline in each Open, that likely indicates playing the Scottish Open or John Deere the week before was a better strategy. I then gathered data for the prior week, finding who played in Scotland or Illinois.

My results were very convincing that playing the Scottish Open gave a player an advantage. On average, golfers who played the Scottish Open performed around 0.65 strokes/round better than those who played in the John Deere, relative to their baseline expectation (John Deere players were around 0.9 strokes worse than expected and Scottish Open players were around 0.25 strokes worse than expected). I had 144 players in the John Deere sample and 310 in the Scottish Open sample. The results are below denominated in strokes compared to PGA Tour average; negative numbers indicate performance better than average and in the difference column positive numbers indicate worse performances.

british open prep

The results were consistent in each of the six seasons I examined. Players who played the Scottish Open always were advantaged over those playing the John Deere, by between 0.2 strokes/round to 1.5 strokes/round. I ran simulations using the baseline expectations, normal observed standard deviations, and the sample sizes from the last six years. The simulations showed a difference of the size measured in favor of the Scottish Open players less than 1% of time. Based on the size of the effect and the fairly large samples for both tournaments, I think it’s very unlikely this is simply variance.

My current methods don’t allow me to completely tease out what factors are contributing to that advantage. The group of golfers who played neither event the week before underperformed their expectation by 0.43 strokes (compared to 0.83 for John Deere and 0.25 for Scottish Open). Mixed in that are golfers who competed elsewhere in the world the week before The Open (Asian Tour, Japan, etc.), golfers who arrived in Britain for prep the same week as the Scottish Open and didn’t compete anywhere, golfers who arrived in Britain at the same time as the John Deere competitors, and European based golfers who didn’t compete anywhere. All this indicates is that there appears to be some advantage to playing the Scottish Open and some disadvantage to playing the John Deere classic.

Perhaps there is some residual home continent advantage to getting used to the time change over the course of ten days, rather than three. Perhaps the value of an extra week preparing on a links course is actually sizable. There’s also the fact that most of the sample of Scottish Open players are regular European Tour players with slightly more experience playing links style courses. While I don’t think overall experience plays much of a role in this difference, it’s likely a small factor. It’s clear however that something is causing players from the John Deere to dramatically under-perform relative to those who are playing in the Scottish Open. In future seasons PGA Tour players qualifying for the Scottish Open would be better served taking advantage of the invitation in order to better perform the following week.

One response to “Performance Impact of Playing John Deere Classic vs. Scottish Open

  1. Pingback: British Open at Old Course Preview – 2015 | Golf Analytics

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