I.T.N. No. 5
PUBLISHED June 3, 2019
Inside The Numbers ...
is a brief numerical summary of the current happenings in the world golf, published every Monday — hopefully.
Patrick Cantlay has been on a steady upward trajectory in the Data Golf Rankings since early March when he was ranked 15th. After last week’s victory, Cantlay ascended to #2 in the rankings, behind only 1 golfer: Dustin Johnson. Over his last 20 rounds, Cantlay has averaged a true strokes-gained of +3.24 — tops in the world. Cantlay was a forgotten man in the 2018 U.S Ryder Cup selection process; it seems unlikely that will happen again anytime soon.
Patrick Cantlay beat the field at the Memorial Tournament by 4.8 strokes per round. Due to the fact that this field was better than your typical PGA Tour field, this translates to a true strokes-gained of 5.3 per round. Given no other information, we would expect Cantlay’s performance to result in a win 97% of the time. That is, Cantlay accumulated 0.97 expected wins from this performance. Adam Scott, who finished 2 strokes back of Cantlay, would have been expected to win about 85% of the time given his strokes-gained performance. For some historical context around just how good Cantlay’s (and Scott’s) performances were, here are the winning true strokes-gained numbers from every PGA Tour event since 2004 (with Cantlay's performance marked in red).
At last week’s Memorial Tournament, Luke Donald followed up a slick third round 65 with a disastrous fourth round 80. After adjusting for course difficulty, this works out to an astonishing difference in performance of 14.67 strokes between the two days! Just how unlikely is it for a difference like this to arise? If you were to select 2 consecutive PGA Tour rounds (from the same golfer) at random, the probability that they would differ by at least 14.67 strokes would be just 0.016%, or roughly 1 in 6200. In other words, not very often. Of course, given how many rounds are played on the PGA Tour every year (~20K), we should expect these things to happen every once in a while.
This week’s field at the RBC Canadian has attracted some of the game’s stars in Rory McIlroy, Dustin Johnson, Brooks Koepka, and others. Beyond this top tier however, the RBC field is not a strong one. The share of the win probability going to the top 10 players in the RBC Canadian Open is 59%. Since the start of the 2019 season, this is the highest share among PGA Tour events with more than 30 participants. The average win probability share amongst that sample was 42%, while the smallest such share occurred at the Safeway Open, with the top 10 golfers in that field garnering just 26% of the win probability.
Chris Baker finished in a 2-way tie for 4th at last week’s REX Hospital Open on the Web.com Tour, while Ryan Armour finished in a 5-way tie for 22nd at the PGA Tour’s Memorial Tournament. For this, they both received approximately the same number of Official World Golf Rankings points (~3.8). Who performed better? Our model deemed these two performances to both be about 1.8 strokes per round better than an average PGA Tour field. This is exactly what we want to see from a rankings system: equal performances receiving equal points. On the whole, the Web.com and PGA Tour’s respective OWGR point allocations achieved that last week.