What Are the Unwritten Rules of Baseball?
In this article
Baseball's unwritten rules are informal codes of etiquette that players follow but that aren't in the official rulebook. They're mostly about respect: for opponents, for the game and for the idea of not "showing up" another team. Breaking one can lead to words, a pitch thrown inside, or a bench-clearing argument.
The best-known unwritten rules
Don't run up the score
- Don't steal bases with a big lead late in the game.
- Don't swing at a 3-0 pitch with a big lead. (This one is fading. See the 3-0 count.)
- Don't bunt to break up a no-hitter in a close game's late innings.
Don't show up the opponent
- Don't admire your home run or flip your bat (traditionally).
- Don't celebrate a strikeout too hard in an opponent's face.
- Don't walk across the mound while the pitcher is warming up or between innings.
- Don't stand on the pitcher's rubber or the other team's logo.
Respect the game
- Don't talk about a no-hitter in your own dugout while it's in progress.
- Don't step on the foul lines when taking the field (a superstition as much as a rule).
- Run out every ground ball and pop-up.
- Don't show up an umpire by arguing balls and strikes theatrically.
Protect your teammates
- Everyone leaves the dugout in a bench-clearing brawl, even if they just stand around.
- If your hitter gets plunked on purpose, your pitcher may retaliate by hitting one of theirs. That's the most dangerous part of the code, and the reason umpires issue warnings quickly. See charging the mound and chin music.
How the code is changing
Younger players grew up watching bat flips in Korea and Latin America and celebrating big moments, and MLB itself leaned into it with its "Let the Kids Play" campaign. Today bat flips are widely accepted, swinging 3-0 with a lead draws far less criticism, and stricter umpires mean fewer retaliation pitches. Respect still matters, but the line has moved.
Unwritten rules vs. real rules
Some things that feel like unwritten rules are actually in the rulebook, like a pitcher throwing at a batter on purpose, which can get him ejected. For outright rule-breaking, see our guide to examples of cheating in baseball.
Related reading
Frequently asked questions
What are baseball's unwritten rules?
They are informal codes of etiquette and sportsmanship that players follow but that aren't in the rulebook, such as not stealing bases with a big late lead or not talking about a no-hitter in progress.
Is bat flipping against the unwritten rules?
Traditionally, yes. Admiring a home run was seen as showing up the pitcher. Today bat flips are widely accepted in MLB and common in leagues like Korea's KBO.
What happens if you break an unwritten rule?
Usually words, glares or a pitch thrown inside or at a hitter in retaliation, which can lead to warnings, ejections and brawls.
Is swinging on 3-0 with a big lead against the unwritten rules?
Some old-school players think so. Many modern players and managers disagree, especially since teams can come back from big leads late.
