Gdula's Golf Simulations: Charles Schwab Challenge
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.
For now, I'm averaging out both models.
Here are the results for the Charles Schwab Challenge.
Win Odds
| Golfer | Simulated Win% |
FanDuel Sportsbook Win Odds |
Golfer | Simulated Win% |
FanDuel Sportsbook Win Odds |
|---|---|---|---|---|---|
| Rory McIlroy | 10.4% | +800 | Jon Rahm | 6.9% | +1200 |
| Justin Thomas | 5.4% | +1600 | Xander Schauffele | 3.8% | +3300 |
| Webb Simpson | 3.4% | +2500 | Dustin Johnson | 2.8% | +2800 |
| Justin Rose | 2.5% | +4500 | Bryson DeChambeau | 2.4% | +2200 |
| Brooks Koepka | 2.3% | +2500 | Patrick Reed | 2.2% | +3000 |
| Matt Kuchar | 2.2% | +4500 | Rickie Fowler | 2.0% | +3500 |
| Sungjae Im | 1.8% | +3300 | Shane Lowry | 1.8% | +5500 |
| Collin Morikawa | 1.7% | +4500 | Louis Oosthuizen | 1.6% | +6500 |
| Gary Woodland | 1.6% | +5000 | Tony Finau | 1.6% | +4000 |
| Billy Horschel | 1.6% | +8000 | Erik van Rooyen | 1.4% | +16000 |
| Ryan Moore | 1.1% | +12000 | Marc Leishman | 1.0% | +4200 |
| Ian Poulter | 1.0% | +15000 | Matthew Fitzpatrick | 0.9% | +4500 |
| Jason Day | 0.9% | +6500 | Kevin Na | 0.9% | +5500 |
| Abraham Ancer | 0.8% | +7500 | Charles Howell III | 0.8% | +17000 |
| Jason Kokrak | 0.8% | +15000 | Joaquin Niemann | 0.8% | +8500 |
| Jordan Spieth | 0.8% | +3500 | Chez Reavie | 0.8% | +10000 |
| Kevin Kisner | 0.7% | +8000 | Byeong Hun An | 0.7% | +6500 |
| Sergio Garcia | 0.7% | +6500 | Matt Wallace | 0.7% | +20000 |
Rory McIlroy (+800) is the heavy favorite on Golf odds but isn't really totally overpriced despite the tough field. McIlroy's data really puts him on another level than the rest of the golfers on the planet. It's just a matter of how well he transitions after the layoff. I can also still see the case for starting your card with Jon Rahm or Justin Thomas.
For me, though, I went down the list a bit further and started off with Xander Schauffele, who really was rounding into form in the spring. Schauffele is a great driver of the golfball both in terms of distance and accuracy, and his short game was trending up, as well.
Justin Rose (+4500) also has positive expected value on his name. We're all a bit tired of him, I'm sure, but he changed his clubs again and if we use long-term form, he's an easy justification at the price. Louis Oosthuizen (+6500) is in a somewhat similar boat. The data points to slight value on him.
Billy Horschel (+8000), Matt Wallace (+20000), and even Vaughn Taylor (+25000) are viable in the top-10 market.
So far this week, my betting card has featured Schauffele, Brooks Koepka, Collin Morikawa, Viktor Hovland, and Joaquin Niemann.
