- The traditional abbreviation for a strikeout. A backwards K is often used to denote a called strikeout. Invented by Henry Chadwick by taking the "most prominent" letter and reinforcing it with an inferred knockout, the connotation still exists when an announcer says the pitcher "punched out" the batter, a play on words that also refers to punching a time clock and to the motion a home plate umpire usually makes on a called third strike.
keep off the boards
- Also singular, "keep off the board". Keep a team from scoring, and hence off the scoreboard. "Wainwright has kept runs off the board at a better rate than Lester." "After loading the bases with one down in the fourth, the Gators were kept off the board by Barham."
keep the hitter honest
- A pitcher needs to mix up his pitches and thereby "keep the hitter honest" by making it difficult for the hitter to anticipate the type, speed, and location of the next pitch. Sometimes this means throwing a brushback pitch to keep the batter from leaning over the plate to reach a pitch on the outer part of the plate. "Partially with Boston in mind, Wang focused this spring on expanding his repertoire to keep hitters honest and move them off the plate."
keep the line moving
- A reference to a series of batters getting on base safely and advancing runners on base, alluding to an assembly line. "Beltran's popout tore apart a rally that had shaken the Hall of Fame-bound Rivera, molding a game out of what moments before had been a five-run rout. Instead, Beltran couldn't keep the line moving, leaving an eager David Wright awaiting on deck." The 2015 Kansas City Royals were one of the most notable examples of "keeping the line moving" during their postseason run, which led to a World Series title.
- Second base.
- Together the shortstop and second baseman – the fielders nearest second base, often combining on double plays – are sometimes referred to as the keystone combination.
- A player who makes an error fielding a ground ball may be said to have "kicked the ball" or "kicked it".
- A batter who hits the ball very far may be said to have "killed the ball".
- A pitcher who stifles a rally by the opposing team may be said to have "killed the rally".
- A breaking ball (usually a curveball) that breaks very sharply, so much so that it freezes the hitter. It starts out directly at the batter (knees buckling out of fear) and then drops into the strike zone.
- Knock in: To score an RBI. "Kenny Lofton knocked in the go-ahead run with a 10th-inning single Thursday afternoon as the Cleveland Indians beat Detroit, 3-1."
- A hit: as in "a two-base knock".
- Knocks: Hard hits or extra-base hits, not necessarily producing RBIs or referring to a specific type of hit. "Curtis had some solid knocks today."
- Knocked around: A pitcher who gives up a lot of hits and gets removed from the game is said to have been knocked around or knocked out of the box or knocked out of the game. Example headline: "Toronto 7, Detroit 4: Phil Coke knocked around; Tigers' bats don't respond".
- Knock down: an infielder who stops a line drive from getting through the infield "knocks it down", perhaps then picking up the ball and throwing the runner out.
- Knock off: to knock off an opponent is to win the game. "Hawai'i knocks off Santa Clara."
- Knock the cover off the ball: to hit a baseball extremely hard. See also tore the cover off the ball.
- A pitch thrown with no spin, traditionally thrown with the knuckles, but also with the fingertips. It tends to flutter and move suddenly and erratically on its way to the plate. Also refers to a batted ball that flutters "like a knuckleball". SYNONYMS: knuckler, flutterball, butterfly ball, floater, bug.
- "Social Media". MLB.com.
- "Archived copy". Archived from the original on 2012-03-22. Retrieved 2009-10-01.CS1 maint: archived copy as title (link)
- "Archived copy". Archived from the original on 2012-11-03. Retrieved 2009-08-04.CS1 maint: archived copy as title (link)
- Anthony DiComo, "Knack in Clutch Spots Eludes Mets", MLB.com, June 16, 2007.
- Flanagan, Jeffrey. "KC makes 'keep the line moving' a way of life". mlb.com. Major League Baseball. Retrieved 2 November 2015. CS1 maint: discouraged parameter (link)
- Kerkhoff, Blair. "For Royals, keeping the line moving starts with Alcides Escobar and Ben Zobrist". kansascity.com. Kansas City Star. Retrieved 2 November 2015. CS1 maint: discouraged parameter (link)
- [dead link]
- Detroit Free Press, May 7, 2011.
- "Hawai'i knocks off Santa Clara".