Balk

If the pitcher commits an act confusing to the batter with nobody on, stops their delivery, or otherwise violates, play is restarted without penalty and time is called.

If a pitcher repeatedly commits illegal actions without runners on base, they may be subject to ejection for persistently violating the rules.

[10] The major league record in a single season is held by Dave Stewart, who had 16 balks in 1988 while pitching for the Oakland Athletics.

[13] Shaw's balks were blamed on his difficulty adjusting to a then-new point of emphasis in the rules: umpires were told to strictly enforce the section of the balk rule that required the pitcher, when going from the stretch to the set position, to come to a complete stop with his hands together for one full second before pitching.

[12] Knuckleballer Charlie Hough was once called for nine balks in a single major league exhibition game, occurring in March 1988.

On September 27, 2022, Miami Marlins reliever Richard Bleier was called for three balks in a row by first-base umpire John Tumpane, all while facing New York Mets batter Pete Alonso.

"[17] During the 1947 World Series (New York Yankees vs. Brooklyn Dodgers) Spec Shea dropped the ball trying to pick off Jackie Robinson at first base; after at least one other attempt, he dropped the ball and umpire Babe Pinelli waved Robinson to second base.

The first was on August 1 vs. the New York Mets in the bottom of the 10th inning when relief pitcher Josh Walker balked before throwing a single pitch, scoring MJ Melendez and resulting in a 7-6 victory for the Royals.

[23] According to Elias Sports Bureau, the 2023 Royals are the only team in the Live Ball Era to have multiple balk-off wins in a single season.

[24] On June 14, 2019, Dodgers closer Kenley Jansen intentionally balked during a game with the Chicago Cubs.

With the Dodgers leading, 5–3, and two outs in the top of the ninth inning, the Cubs' Jason Heyward was on second base.