baseball statistics Baseball statistics include a variety of metrics used to evaluate player and team performance in the sport of baseball. Because the flow of a baseball game has natural breaks to it, and player activity is characteristically distinguishable ind ...

, strikeout-to-walk ratio (K/BB) is a measure of a

pitcher In baseball, the pitcher is the player who throws ("Pitch (baseball), pitches") the Baseball (ball), baseball from the pitcher's mound toward the catcher to begin each play, with the goal of out (baseball), retiring a batter (baseball), batter, ...

's ability to control pitches, calculated as

strikeout In baseball or softball, a strikeout (or strike-out) occurs when a batter accumulates three strikes during a time at bat. It means the batter is out, unless the third strike is not caught by the catcher and the batter reaches first base safe ...

s divided by

bases on balls A base on balls (BB), better known as a walk, occurs in baseball when a batter receives four pitches during a plate appearance that the umpire calls '' balls'', and is in turn awarded first base without the possibility of being called out. The bas ...

. A

hit by pitch In baseball, hit by pitch (HBP) is an event in which a batter or his clothing or equipment (other than his bat) is struck directly by a pitch from the pitcher; the batter is called a hit batsman (HB). A hit batsman is awarded first base, provide ...

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 In baseball statistics Baseball statistics include a variety of metrics used to evaluate player and team performance in the sport of baseball. Because the flow of a baseball game has natural breaks to it, and player activity is characteristica ...

(BB/K).

Leaders

A pitcher who possesses a great K/BB ratio is usually a dominant

power pitcher Power pitcher is a term in baseball for a pitcher who relies on pitch velocity at the expense of accuracy. Power pitchers usually record a high number of strikeouts, and statistics such as strikeouts per 9 innings pitched are common measures o ...

, such as

Randy Johnson Randall David Johnson (born September 10, 1963), nicknamed, "the Big Unit," is an American former professional baseball pitcher who played 22 seasons in Major League Baseball (1988–2009) for six teams, primarily the Seattle Mariners and Arizo ...

Pedro Martínez Pedro Jaime Martínez (born October 25, 1971) is a Dominican-American former professional baseball starting pitcher, who played in Major League Baseball (MLB) from to , for five teams—most notably the Boston Red Sox from to . As of 2023, M ...

Curt Schilling Curtis Montague Schilling (born November 14, 1966) is an American former Major League Baseball right handed pitcher and commentator for media outlet BlazeTV. He helped lead the Philadelphia Phillies to a World Series appearance in 1993 World Seri ...

, or

Mariano Rivera Mariano Rivera (born November 29, 1969) is a Panamanian Americans, Panamanian-American former professional baseball pitcher who played 19 seasons in Major League Baseball (MLB) for the New York Yankees, from 1995 to 2013. Nicknamed "Mo" and " ...

. However, in 2005,

Minnesota Twins The Minnesota Twins are an American professional baseball team based in Minneapolis. The Twins compete in Major League Baseball (MLB) as a member club of the American League (AL) American League Central, Central Division. The team is named afte ...

starting pitcher In baseball (hardball or softball), a starting pitcher or starter is the first pitcher in the game for each team. A pitcher is credited with a game started if they throw the first pitch to the opponent's first batter of a game. Starting pit ...

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. Through 2022, the all-time career leaders among starting pitchers were

Chris Sale Christopher Allen Sale (born March 30, 1989) is an American professional baseball pitcher for the Atlanta Braves of Major League Baseball (MLB). He has previously played in MLB for the Chicago White Sox and Boston Red Sox. He throws left-handed ...

(5.3333), Jacob de Grom (5.3036), and

Tommy Bond Thomas Ross Bond (September 16, 1926 – September 24, 2005) was an American actor, director, producer and writer. He was best known for his work as a child actor for two nonconsecutive periods in ''Our Gang'' (''Little Rascals'') comedies (fir ...

(5.0363). Through May 22, 2019, the all-time career leaders among relievers were Koji Uehara (7.94), Sean Doolittle (6.41), and

Roberto Osuna Roberto Osuna Quintero Jr. (born February 7, 1995) is a Mexican professional baseball pitcher for the Fukuoka SoftBank Hawks of Nippon Professional Baseball (NPB). He has previously played in Major League Baseball (MLB) for the Toronto Blue Jay ...

(6.33). The player with the highest single regular season K/BB ratio through 2022 was

pitcher Phil Hughes in 2014, with a ratio of 11.625 (186 strikeouts and 16 walks). He is followed by

Bret Saberhagen Bret William Saberhagen (; born April 11, 1964) is an American former professional baseball right-handed starting pitcher. He played in Major League Baseball (MLB) for the Kansas City Royals, New York Mets, Colorado Rockies, and Boston Red Sox fr ...

(11.00 in 1994) and Cliff Lee (10.28 in 2010).

References

Pitching statistics Statistical ratios {{Baseball-stub