Gdula’s Golf Simulations: Arnold Palmer Invitational
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 years, I have made plenty of tweaks to my original golf model, which uses 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 is 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.
In addition to that long-term adjusted form, I factor in course-level adjustments for course fit.
I run a second model that uses more granular strokes gained data, which allows me to adjust for course fit very easily. The results are averaged out.
I let the data do the talking and don’t make many tweaks — if any. Golfers with a small sample get regressed to a low-end PGA Tour player to round out their samples. Data points are weighted more heavily toward recent performance.
Here are the most likely winners for the Arnold Palmer Invitational, according to the models.
| Golfer | Simulated
Win% |
Simulated
Top-10% |
Simulated
Made Cut% |
FanDuel
Sportsbook Win Odds |
|---|---|---|---|---|
| Bryson DeChambeau | 7.7% | 41.5% | 88.3% | +1300 |
| Rory McIlroy | 6.1% | 30.7% | 82.7% | +950 |
| Viktor Hovland | 5.1% | 31.5% | 83.5% | +1200 |
| Tyrrell Hatton | 5.0% | 31.7% | 83.3% | +1700 |
| Patrick Reed | 4.5% | 30.4% | 82.4% | +2100 |
| Matthew Fitzpatrick | 3.7% | 26.1% | 80.5% | +2300 |
| Harris English | 2.7% | 22.8% | 78.2% | +6500 |
| Will Zalatoris | 2.3% | 20.4% | 76.2% | +3800 |
| Hideki Matsuyama | 2.1% | 17.7% | 74.2% | +2700 |
| Jason Kokrak | 2.1% | 18.1% | 74.2% | +4900 |
| Paul Casey | 2.1% | 17.6% | 73.9% | +2400 |
| Sungjae Im | 1.9% | 16.1% | 72.4% | +2100 |
| Billy Horschel | 1.9% | 17.1% | 72.8% | +3500 |
| Sam Burns | 1.9% | 17.0% | 73.5% | +4900 |
| Louis Oosthuizen | 1.8% | 16.9% | 72.6% | +3900 |
| Jason Day | 1.7% | 15.5% | 71.7% | +3200 |
| Kevin Kisner | 1.5% | 16.4% | 72.0% | +6500 |
| Cameron Tringale | 1.4% | 14.7% | 71.2% | +7000 |
| Lanto Griffin | 1.4% | 14.0% | 69.9% | +10000 |
| Cameron Davis | 1.4% | 14.1% | 70.8% | +6500 |
| Francesco Molinari | 1.3% | 11.9% | 67.4% | +3500 |
| Corey Conners | 1.3% | 15.3% | 71.3% | +14000 |
| Kevin Na | 1.3% | 13.6% | 69.5% | +5500 |
| Brendon Todd | 1.2% | 13.1% | 68.3% | +14000 |
| Jordan Spieth | 1.2% | 10.5% | 64.9% | +3000 |
| Christiaan Bezuidenhout | 1.1% | 12.2% | 67.2% | +7500 |
| Talor Gooch | 1.1% | 11.5% | 66.9% | +10000 |
| Max Homa | 1.0% | 10.8% | 66.0% | +6500 |
| Si Woo Kim | 1.0% | 12.4% | 68.5% | +9000 |
| Tommy Fleetwood | 0.9% | 10.2% | 64.7% | +4400 |
| Ian Poulter | 0.9% | 10.6% | 65.6% | +15000 |
| Harold Varner III | 0.9% | 9.6% | 63.2% | +15000 |
| Zach Johnson | 0.8% | 10.9% | 65.5% | +17000 |
| Charley Hoffman | 0.7% | 10.2% | 65.7% | +10000 |
| John Huh | 0.7% | 9.4% | 63.8% | +18000 |
| Henrik Norlander | 0.7% | 8.4% | 61.9% | +14000 |
| Shane Lowry | 0.7% | 9.2% | 63.4% | +10000 |
| Brendan Steele | 0.7% | 9.0% | 63.1% | +15000 |
| Erik van Rooyen | 0.6% | 8.8% | 62.4% | +13000 |
| Rickie Fowler | 0.6% | 8.5% | 63.0% | +8000 |
| Justin Rose | 0.6% | 7.8% | 60.9% | +6000 |
| Sebastian Munoz | 0.6% | 8.0% | 60.6% | +14000 |
| Marc Leishman | 0.6% | 4.0% | 52.3% | +4100 |
| Sepp Straka | 0.6% | 8.3% | 61.5% | +29000 |
| Dylan Frittelli | 0.6% | 7.8% | 61.6% | +18000 |
To be honest, these numbers at the top are a tad lower than I expected for Bryson DeChambeau and Rory McIlroy, but they make sense for how the models work. DeChambeau’s not the most elite with his irons, and there’s an emphasis on those this week, and McIlroy’s long-term form is still bogging down the solid — not elite — recent performance (even with the more recent data weighted more heavily. It’s hard to argue McIlroy’s results at Bay Hill, but at +950, there’s not any actual value on him. DeChambeau is showing some value at +1300.
Viktor Hovland‘s red hot but is overvalued, per the models, though things set up well for him at a ball-striker’s course.
Tyrrell Hatton, the defending champ, is more justifiable at +1700, and so is Patrick Reed at +2100. Matthew Fitzpatrick (+2300) is appealing as well if the course brings some wind this week. Of note, the past five winners here (Hatton, Francesco Molinari, McIlroy, Marc Leishman, and Jason Day) are non-Americans.
I’m seeing more value down the card this week with Jason Kokrak (+4900), Sam Burns (+4900), Kevin Kisner (+6500), Cameron Tringale (+7000), Lanto Griffin (+10000), and Cameron Davis (+6500) as solid options.
The name value for DeChambeau and McIlroy is reflected in the betting odds, but the models are a little more skeptical, so it could be a week to pepper the second and third tiers.
I’ll update this closer to Thursday with my actual picks.