Skill, Luck, and Streaky Play on the PGA Tour

In this study, we implement a random-effects model that estimates cubic spline-based time-dependent skill functions for 253 active PGA Tour golfers over the 1998–2001 period. Our model controls for the first-order autocorrelation of residual 18-hole scores and adjusts for round–course and player–course random effects. Using the model, we are able to estimate time-varying measures of skill and luck for each player in the sample. Estimates of spline-based player-specific skill functions provide strong evidence that the skill levels of PGA Tour players change through time. Using the model, we are able to rank golfers at the end of 2001 on the basis of their estimated mean skill levels and identify the players who experienced the most improvement and deterioration in their skill levels over the 1998–2001 period. We find that some luck is required to win PGA Tour events, even for the most highly skilled players. Player–course interactions contribute very little to variability in golfer performance, but the particular course rotations to which players are assigned can have a significant effect on the outcomes of the few tournaments played on more than one course. We also find evidence that a small number of PGA Tour participants experience statistically significant streaky play.