In baseball statistics, Walks plus hits per inning pitched (WHIP) is a sabermetric measurement of the number of baserunners a pitcher has allowed per inning pitched. It is a general measure of a pitcher's ability to prevent batters from reaching base. Along with on-base plus slugging (OPS) for hitters, WHIP is one of the few sabermetric statistics to enter mainstream baseball usage. It is one of the most commonly used statistics in fantasy baseball, and is standard in fantasy leagues that use the 4×4, 5×5, and 6×6 formats.