World Baseball Classic Rules

Table introducing The World Baseball Classic Rules

Eligibility
In addition to the standard rules of baseball, the World Baseball Classic employs the following additional rules:

A player is eligible to participate on a World Baseball Classic team if any one of the following criteria is met:
 * The player is a citizen of the nation the team represents.
 * The player is qualified for citizenship or to hold a passport under the laws of a nation represented by a team, but has not been granted citizenship or been issued a passport; in this case, the player may be made eligible by World Baseball Classic Inc. upon petition by the player or team.
 * The player is a permanent legal resident of the nation or territory the team represents.
 * The player was born in the nation or territory the team represents.
 * The player has one parent who is, or if deceased was, a citizen of the nation the team represents.
 * The player has one parent who was born in the nation or territory the team represents.

Pitching
A pitcher cannot pitch more than:
 * 85 pitches per game in the Qualifying Round (all tournaments since 2013, when this round was introduced)
 * 65 pitches per game in the First Round (all tournaments except 2009, in which the limit was 70)
 * 80 pitches per game in the Second Round (all tournaments except 2009, in which the limit was 85)
 * 95 pitches per game in the Championship Round (all tournaments except 2009, in which the limit was 100)

A pitcher can still finish a batter's plate appearance even if the limit is reached, but must come out after completing the plate appearance.

A pitcher cannot pitch until:
 * a minimum of four days have passed since he last pitched, if he threw 50 or more pitches when he last pitched
 * a minimum of one day has passed since he last pitched, if he threw 30 or more pitches when he last pitched
 * a minimum of one day has passed since any second consecutive day on which the pitcher pitched

In 2024, the Nippon Professional Baseball players' union said it was opposed to introducing the pitch clock at the 2026 World Baseball Classic.

Mercy rules
To prevent one-sided contests, games are ended early if one team is ahead by:


 * 10 or more runs after any complete inning, beginning with the completion of the seventh inning, or;
 * 15 or more runs after any complete inning, beginning with the completion of the fifth inning

These mercy rules do not apply during the knockout stage.

Designated hitter
The designated hitter rule applies for all games.

Extra innings
From 2009 through 2017, starting with the 11th inning, teams automatically start with runners on first and second base. The baserunners are the players in the two batting order positions previous to the leadoff batter for the inning (or substitutes called in to pinch-run for those players). Organizers put this rule in place starting with the 2009 tournament, although originally, it did not come into effect until the 13th inning. The intention behind the rule is to help ensure extra-inning games end in as timely a manner as possible, reducing the chance of seeing marathon extra-inning games that place undue strain on players, particularly pitchers. As no extra-inning games in either the 2009 or 2013 WBCs reached the point where the rule came into play, it took until the 2017 WBC for it to affect a game's outcome. There were three such games in 2017, and all three were decided in the 11th inning.

In 2023, the rule was changed to bring the WBC in line with Major League Baseball. The 2023 World Baseball Classic rules and regulations reads: "For any inning beginning with the 10th inning, the Federation Team at bat shall begin the inning with a runner on second base. The batter who leads off an inning shall continue to be the batter who would lead off the inning in the absence of this extra-innings rule. The runner on second base shall be the player (or a substitute for such player) in the batting order immediately preceding the batter who leads off the inning."

Video replay review
Beginning in the 2023 World Baseball Classic, video review is available for all situations as it would be during a Major League Baseball regular season game.

Run differential
Unlike regular season play, where the number of runs by which a team wins a game is not relevant, the number of runs by which a WBC team wins may be relevant if a tie later develops in the standings. In such cases, teams are ranked by their Team Quality Balance, which rewards them for scoring by as many runs as possible, and for winning with as few of their batters getting out as possible when batting in the bottom of the inning. This caused problems during the 2013 WBC, where one game spawned a bench-clearing brawl between the Canadian and Mexican teams (Canadian hitter Chris Robinson had bunted for a base hit after Canada had already taken a large lead, causing Mexican pitcher Arnold Leon to throw three consecutive pitches at the next hitter, Rene Tosoni).

These tiebreakers were changed starting in the 2017 WBC to be "fewest runs allowed per inning of defense in head-to-head games", which still places an emphasis on scoring as many runs as possible (whilst also allowing the fewest runs as possible).