Strikeout-to-walk ratio
In baseball statistics, strikeout-to-walk ratio is a measure of a pitcher's ability to control pitches, calculated as strikeouts divided by bases on balls.
A hit by pitch is not counted statistically as a walk and therefore not counted in the strikeout-to-walk ratio.
The inverse of this calculation is the related statistic for hitters, walk-to-strikeout ratio.Leaders
Through May 24, 2019, the all-time career leaders among starting pitchers are Chris Sale, Tommy Bond, and Corey Kluber.
Through May 22, 2019, the all-time career leaders among relievers are Koji Uehara, Sean Doolittle, and Roberto Osuna.
.
The player with the highest single regular season K/BB ratio through 2018 was Minnesota Twins pitcher Phil Hughes in 2014, with a ratio of 11.625. He is followed by Bret Saberhagen and Cliff Lee. Despite pitching only 149 innings in 2016, Clayton Kershaw set a new record for K/BB ratio by striking out 172 batters while walking only 11 for a ratio of 15.6.
A pitcher who possesses a great K/BB ratio is usually a dominant power pitcher, such as Randy Johnson, Pedro Martínez, Curt Schilling, or Mariano Rivera. However, in 2005, Minnesota Twins starting pitcher Carlos Silva easily led the major leagues in K/BB ratio with 7.89:1, despite striking out only 71 batters over 188⅓ innings pitched; he walked only nine batters.