Gdula's Golf Simulations: TOUR Championship
Volatility is the name of the game in golf, and picking winners isn't easy. With fields of 150-plus golfers sometimes being separated by how a putt or two falls each week, predicting golf can be absurdly tough.
We'll never be able to capture everything that goes into a golfer's expectations for a week, but we can try to account for that by simulating out the weekend and seeing what happens.
The Process
Over the hiatus, I made some tweaks to my original golf model, which used a combination of the OWGR's field strength numbers and datagolf's field strength numbers to adjust each golfer's score relative to the field (on the PGA Tour, the European Tour, and the Korn Ferry Tour). The ultimate goal was to place a score from the Waste Management Open, the BMW International Open, and the Knoxville Open on level playing fields. This adjusted strokes metric lets me see how golfers are performing across all tours. From there, a golfer's adjusted stroke data is combined with their round-to-round variance to see how the field is likely to perform when playing out the event thousands of times.
I liked it, and it worked, but it didn't isolate out tee-to-green and putting performance enough, so I made some alterations, this time leveraging strokes gained data and adjusting that for field strength.
After using an average of those two models, I've now swapped to the newer model, which has fared better and is capable of easier course-level adjustments.
Here are the simulation results for the TOUR Championship. (Starting score is in parentheses.)
| Golfer | Simulated Win% |
FanDuel Sportsbook Win Odds |
Golfer | Simulated Win% |
FanDuel Sportsbook Win Odds |
|---|---|---|---|---|---|
| Dustin Johnson (-10) |
26.7% | +175 | Jon Rahm (-8) |
23.6% | +250 |
| Justin Thomas (-7) |
16.7% | +550 | Webb Simpson (-6) |
7.8% | +1200 |
| Bryson DeChambeau (-4) |
3.5% | +2000 | Rory McIlroy (-3) |
3.0% | +2000 |
| Collin Morikawa (-5) |
2.8% | +1800 | Xander Schauffele (-3) |
2.7% | +2700 |
| Daniel Berger (-4) |
2.7% | +2700 | Hideki Matsuyama (-4) |
2.1% | +2900 |
| Patrick Reed (-3) |
1.2% | +5000 | Scottie Scheffler (-2) |
1.2% | +8000 |
| Sungjae Im (-4) |
1.2% | +10000 | Harris English (-4) |
1.1% | +5000 |
| Tyrrell Hatton (-2) |
0.8% | +10000 | Tony Finau (-2) |
0.8% | +5000 |
| Sebastian Munoz (-3) |
0.4% | +15000 | Lanto Griffin (-2) |
0.3% | +32000 |
| Brendon Todd (-3) |
0.3% | +10000 | Joaquin Niemann (-2) |
0.2% | +15000 |
| Abraham Ancer (-1) |
0.2% | +21000 | Kevin Kisner (-1) |
0.2% | +12000 |
| Billy Horschel (E) |
0.2% | +21000 | Viktor Hovland (E) |
0.1% | +21000 |
| Kevin Na (-1) |
0.1% | +42000 | Ryan Palmer (-1) |
0.1% | +32000 |
| Cameron Champ (E) |
0.0% | +42000 | Cameron Smith (E) |
0.0% | +42000 |
| Mackenzie Hughes (E) |
0.0% | +42000 | Marc Leishman (-1) |
0.0% | +50000 |
These odds -- both the sims and betting odds -- account for the strokes that these golfers are spotted based on their FedEx Cup ranking.
Dustin Johnson starts this week -10 and is red hot. The +175 odds on Golf odds are wild and imply a 36.4% chance to win. For that reason, I'm out. Jon Rahm was second in my win sims last week, but I didn't see enough value, unfortunately. The same can be said this week, as he should be around 28.6% likely to win at +250 odds but falls short of that.
It's Justin Thomas that interests me most at the top. He starts -7 and is getting a lack of respect at +550 in the 30-man field. He outperformed those odds and has finished top-seven here four straight years.
We'll have to track the status of Webb Simpson (+1200), but he's priced appropriately, based on the sims. The same can be said for Harris English (+5000), Tyrrell Hatton (+10000), and Sungjae Im (+10000).
Because of the starting strokes, it's a tough week to find significant value, but Thomas is my early interest this week. If we forgive the search for just positive value, Rory McIlroy and Xander Schauffele draw my attention.
I've bet Justin Thomas and Sungjae Im to win.
