COLLEGE OF THE HOLY CROSS Clutch Strokes: Performance Under Pressure in Golf Jeffrey Paadre This paper examines 10 years worth of PGA Tour Tournament data in order to examine whether or not clutch performance exists during the final round of a tournament. After controlling scores for differences in course difficulty, the paper finds no evidence of tangible clutch performance. The authors find that the perception of clutch performance is more likely attributable to talent differential between golfers. Assuming a normal distribution of golfer talent, it is possible that Tiger Woods can outshoot his opponents on the final day of a tournament as well as lose his lead to his competitors. Motivation and Literature In professional sports, heroes can be created through the concept of clutch performance. The perception of clutch performance occurs when an athlete raises his or her performance to an extraordinary level during the most important moments of a sporting event. Athletes such as David Ortiz and Adam Vinatieri have been immortalized as legends due to their consistent ability to help their teams win baseball and football games during important games where the outcome was hanging in the balance. Conversely Bill Buckner and Scott Norwood are amongst the unfortunate athletes burdened with reputations as choke artists based on their inability to perform well when their teams needed a high performance the most. One of the challenges that accompanies examining performance under pressure lies within trying to define which performances constitute clutch performance. For example, in 2005 John Henry, the owner of the Boston Red Sox, presented David Ortiz with a plaque inscribed “David Ortiz: The Greatest Clutch Hitter in the History of the Boston Red Sox”. While Ortiz had played especially well late during close games, Nate Silver, recently famous for his Five Thirty Eight blog where he accurately predicted the 2012 Electoral College by weighing various political polls, found that clutch hitting as he defined it, had no correlation from one season to another, implying that at least in baseball, it is difficult for a player to sustain clutch performance (Silver 2006). Silver's definition of clutch included estimating a player's marginal lineup value, translating that figure into wins produced, accounting for how often a player appears at the plate in pressure situations and then estimating the expected amount of wins the player would produce given his talent and the scenarios he faces. Silver defines clutch as the difference between the amount of wins a player produced in a season and the amount of wins he could have been expected to produce given his ability. Silver found that through his definition of clutch, David 2 Ortiz exhibited extremely clutch performances in 2005 but that in some other seasons, Ortiz actually performed worse in "clutch situations" than he should have been expected to. This implies that performance in the clutch may be random and that each player may have a mean expected performance in high pressure situations. As seen with Ortiz, his performance relative to this expected value fluctuates from season to season. While Ortiz's season in 2005 is ranked as the 5th best single season clutch score in Silver's analysis, Ortiz is not amongst the 25 players in baseball history with the highest clutch score. This suggests that each player could be expected to stay around their mean clutch score value and that any extreme fluctuation from that average could be random, thus the viewer should expect a regression to the mean in a subsequent season. While baseball may be easier to measure potential clutch performance due to the individual battles occurring during a team game, other team sports typically have too many different factors contributing to the outcome of a game to assign substantial credit to one player’s performance. In basketball for example, whether or not a last second shot goes in is truly the result of the efforts of all 10 players on the court. The defense is equally responsible for the result of a shot attempt, and it would be truly subjective to determine whether a game winning shot should be credited to the offensive player or written off as a result of the opponent’s poor defensive play. The same problem holds true for most other team sports. One study did attempt to examine clutch performance in basketball by observing the differences in free throw percentages for given times and score differentials in games. Free throws in basketball are the only way in which a player can add to his team’s score in a manner that is truly independent from the other 9 players on the court because the shooter stands at the line to take an uncontested shot. Zheng, Price, and Stone (2011) find that NBA players do shoot a worse free throw percentage than expected when their teams are winning or losing by small 3 margins late in games, indicating that if a player can underperform relative to their averages under pressure, or “choke”, other players may remain consistent or outperform their averages during high pressure situations. These players may be identified as clutch performers. Another issue that faces identifying clutch performance is whether or not, based on a player’s abilities, performing well in a key moment should be expected. Streakiness can and often does occur during random events. For example, if a coin is flipped 100 times, the flipper should not be surprised if at some point, 5 or 6 consecutive heads results are obtained. Likewise, in sports, if a basketball player makes on average 50% of his shots, a viewer should not be surprised if that player makes 5 or 6 shots in a row. Extending this, a viewer should not necessarily be surprised if the same player happens to make 5 or 6 shots in a row in supposed “clutch situations”. Monte Carlo simulations often attempt to address the likelihood of various streaks of consecutive successful events by running many simulations with a given probability in order to determine the likelihood of long streaks. In order to combat these inherent problems with examining clutch performance, this paper examines PGA tournament performance. In golf, all elements of a golfer’s score can be attributed to the golfer’s performance. It is also reasonable to assume that all golfers competing in the same tournament are competing on equal playing conditions. The course layout and weather during the rounds are consistent for all of the competitors in a given tournament. Additionally, using years worth of data on both courses and golfers, the statistical likelihood of a golfer’s performance given his ability and the course difficulty can be predicted. In golf, no golfer is more widely regarded as a clutch performer than Tiger Woods. In 2008, Barker Davis of the Washington Post declared that “Fact is, golf has never had a player 4 who always rises to the moment like Woods. Never. Not Jack Nicklaus, not Ben Hogan, not Byron Nelson, not Bobby Jones. Again this week, Woods has proved to be a transcendent player, a player in a pantheon all his own”i. This evaluation of Woods came following a 15 foot putt that Woods made in order to force a playoff in the 2008 US Open against rival golfer Rocco Mediate, while in excruciating pain due to an injured knee. After Woods made the putt to force the playoff Mediate stated "I knew he'd make that putt. That's what he does. He is so hard to beat. He's unreal"ii. The opinion following the made putt was that no golfer performed better under pressure than Woods. Reputations in golf are no different than reputations in other sports; a player's entire career can be defined by single rounds or tournaments. Just as Woods is often known for his clutch play, another elite golfer, Greg Norman, has left a different lasting impression on his audience. In the 1996 Masters Tournament, Norman led Nick Faldo by 6 strokes heading into the final day of the tournament. Not only did Norman lose his lead, he lost to Faldo by 5 strokes. Norman was outshot by his rival by 11 strokes on the final day and finished well behind a golfer he had led by a sizeable margin. For his loss to Faldo, Norman is often regarded as one of the great choke artists in golf, someone who cannot be counted on when the tournament is on the line. Conversely, Woods is known as one of the most clutch golfers in the history of the PGA Tour. Brown (2011) found that Tiger’s mere presence in a tournament event will lead to worse scores by roughly .8 stokes, from each of the other players in the tournament field than they could be expected to score without Woods’ presence. Brown attributes this to many golfers believing that Woods will automatically win the tournament and that everyone else may as well compete for second place. Woods has a colossal reputation as a superstar golfer who performs well under pressure. 5 One statistic often used to defend this point is that prior to the 2009 PGA Championship, Tiger Woods had never lost a Grand Slam tournament where he entered the final round of play with at least a share of the lead. Tiger’s first surrendered lead in a tournament occurred when Y.E. Yang outshot Tiger by 5 strokes in the PGA Championship, overcoming Tiger’s initial two stroke lead. While Tiger has consistently held leads going into the final round of a major tournament, he too has his limits. Tiger has yet to win a major tournament where he did not lead or hold a share of the lead entering the final round of play.