This analytical tool quantifies player performance by comparing the number of strokes taken to complete a hole against a benchmark representing an expected number of strokes. For example, if a player takes four strokes on a par-4 considered a benchmark of 4.5 strokes, the player gains +0.5 strokes on that hole. Aggregating these gains and losses across a round, or even a season, provides a precise measure of performance relative to expectation.
Its development revolutionized golf analytics, providing a more nuanced and objective performance measurement than traditional metrics like scoring average. This method allows for direct comparison of players across different courses and conditions, isolating skill in various aspects of the game, such as putting, driving, and approach shots. This objective data empowers players to identify strengths and weaknesses, facilitating targeted practice and improvement strategies.