Sabermetric

Sabermetrics is the empirical analysis of baseball, emphasizing objective measurement and statistical evaluation of in-game actions to understand player performance, team outcomes, and strategic decisions. It seeks to explain why players perform as they do, compare players across eras, and improve predictions of future results beyond traditional statistics such as batting average or win–loss records.

The term sabermetrics derives from SABR, the Society for American Baseball Research, an organization founded in 1971 to study baseball with systematic research and data collection. The movement was popularized in the late 20th century by researchers including Bill James and his collaborators, who developed and promoted quantitative methods for assessing players and teams.

Key concepts in sabermetrics include a progression from conventional stats to more descriptive and predictive measures. Common metrics include on-base percentage, slugging percentage, and OPS (on-base plus slugging). Advanced metrics such as wOBA (weighted on-base average), wRC+ (weighted runs created plus), and WAR (wins above replacement) aim to summarize overall offensive value. For pitchers, metrics like FIP (fielding independent pitching) and xFIP are used, while defensive analysis employs metrics such as UZR and DRS. Data sources range from traditional box scores to play-by-play data and, since the mid-2010s, Statcast data that tracks ball flight and player movements.

Impact and criticisms: Sabermetrics has influenced player evaluation, contract negotiations, and roster construction in many organizations, and it informs fan analysis as well. Critics note that metrics can oversimplify context, face limitations from small samples, and yield conflicting results across different models.