Predicting Professional Performance of Collegiate Golfers (Part II)
September 5, 2013
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Yesterday, I posted a comprehensive look at the performance of collegiate golfers during their first season in Major Tour (PGA/Web.com/European) professional golf and examined how correlated those results were to Jeff Sagarin’s Rankings at Golfweek. However, I was concerned about that study largely because I did not remove golfers who took several years to actually record >20 Major Tour rounds. It can often be very difficult for the non-elite college golfers to play regularly on the Major Tours right after graduation. Many play on the minor league tours (eGolf/NGA) or one of the international tours (Challenge/Asian/etc.). Obviously, this introduces bias into the study if we’re comparing, for example, Jordan Spieth’s season right after leaving college and Chesson Hadley’s season three years after he graduated. Part of success in pro golf is learning how to endure the grind of a season – securing entrance into tournaments, sponsors, and performing well enough to earn a living. Add to that that golfers almost always become better players from their early 20s to mid 20s, and I’m not sure I trust the reliability of yesterday’s study.
To correct for that bias, I removed all seasons from the sample that occurred more than one year after the golfer’s last in collegiate golf. For example, Keegan Bradley last competed in college in 2008, but did not record Major Tour rounds until 2010. He’s dropped from my sample along with roughly half of the seasons. I followed the same methodology as yesterday using only the seasons that met this new criteria.
N=35, average college seasons = 3.4, average Sagarin = 70.7, average pro performance in Z-Score = 0.10
The results showed a much stronger correlation than yesterday (R=0.70). In fact, this correlation is almost exactly equal to what I found earlier this week when examining the correlation between sets of professional seasons. This indicates that Sagarin’s Rankings are an extremely valuable predictor of professional success, even more so than what I found yesterday.