In baseball, WHIP stands for "Walks plus Hits per Inning Pitched." It is a statistical measure used to evaluate a pitcher's effectiveness at preventing batters from reaching base. WHIP is calculated by adding the total number of walks (BB) and hits (H) allowed by a pitcher and then dividing that sum by the total innings pitched (IP):
WHIP=BB+HIPWHIP=\frac{BB+H}{IP}WHIP=IPBB+H​
This statistic reflects how many baserunners a pitcher allows on average per inning. A lower WHIP indicates better performance, as it means the pitcher is allowing fewer hitters to reach base, thereby reducing scoring opportunities for the opposing team. WHIP excludes hit batsmen, errors, and fielder's choices from its calculation
. WHIP is widely used in both traditional and sabermetric baseball analysis and is considered one of the key metrics for assessing a pitcher's control and effectiveness, alongside earned run average (ERA). While ERA measures runs allowed, WHIP directly measures a pitcher's ability to keep runners off the bases, which correlates strongly with preventing runs
. A WHIP around 1.00 or lower is generally considered excellent, indicating the pitcher allows about one baserunner per inning or fewer. For context, the Major League Baseball average WHIP is about 1.30, and elite pitchers often have WHIPs below 1.00
. Notable pitchers with historically low career WHIPs include Jacob deGrom (0.993), Mariano Rivera (1.00), and Clayton Kershaw (1.004), demonstrating elite control and efficiency in limiting baserunners
. In summary, WHIP is a key pitching statistic that quantifies how many walks and hits a pitcher allows per inning, serving as a direct indicator of their ability to prevent baserunners and thus contribute to their team's defensive success.
