Abstract
The game of golf involves many different types of shots: long tee shots (typically hit with a driver), approach shots to greens, shots from the sand, putts on the green, and others. While it is easy to determine the winner in a golf tournament by counting strokes, it is not easy to assess which factors most contributed to the victory. In this paper we apply an analysis based on strokes gained (previously termed shot value) to assess the performance of golfers in different parts of the game of golf. Strokes gained is a simple and intuitive measure of the contribution of each shot to a golfer's score. Strokes gained analysis is applied to extensive ShotLink data in order to rank PGA TOUR golfers in various skill categories and to quantify the factors that differentiate golfers on the PGA TOUR. Long game shots (those starting over 100 yards from the hole) explain about two-thirds of the variability in scores among golfers on the PGA TOUR. Tiger Woods is ranked number one in total strokes gained and he is ranked at or near the top of PGA TOUR golfers in each of the three main categories: long game, short game and putting. His dominance is a result of excelling at all phases of the game, but his long game accounts for about two-thirds of his scoring advantage relative to the field. A similar approach is used to rank PGA TOUR courses in terms of overall difficulty and difficulty in each part of the game. A preliminary analysis shows that the recent change in the groove rule for irons by the United States Golf Association (USGA) has had almost no impact on scores from the rough.