What Is a Balk in Baseball? The Rule, Penalty and Examples

A balk is an illegal act by the pitcher while at least one runner is on base, and the penalty is that every runner moves up one base. The rule exists to stop pitchers from deceiving runners with fake, incomplete or sneaky motions.

It is one of the least understood calls in baseball, partly because there are more than a dozen ways to commit one and partly because many of them happen in a fraction of a second. This guide covers what counts as a balk under the current Official Baseball Rules, the penalty and its one big exception, why the rule exists, the newer balks created by the 2023 pickoff limits, and a set of plain examples you can picture from the stands.

The balk rule in plain English

The rulebook's definition is short: a balk is an illegal act by the pitcher with a runner or runners on base, entitling all runners to advance one base. The detailed list lives in Rule 6.02(a), with a few more scattered through Rule 5.07, which governs how a pitcher must stand and deliver.

Three ideas sit underneath almost every balk. Once a pitcher starts a motion associated with pitching, he has to finish the pitch. If he throws to a base, he has to step toward that base first and make a genuine attempt at a play. And in the set position, the stance most pitchers use with runners on, he has to come to a complete stop before delivering.

A balk can only happen with runners on base. If the bases are empty and a pitcher does the same illegal thing, Rule 6.02(b) calls it an illegal pitch instead, and the penalty is simply a ball added to the count. There is no runner to deceive, so there is nothing to award.

The main ways a pitcher balks

Rule 6.02(a) lists 13 situations. Translated into everyday language, a pitcher balks when he:

• Starts his pitching motion while touching the rubber and then stops without delivering
• Fakes a throw to first or third base while touching the rubber and does not complete it (a fake to second is still legal)
• Throws to a base without first stepping directly toward it
• Throws or fakes a throw to an empty base, unless he is genuinely trying to make a play
• Makes an illegal pitch, such as a quick pitch fired before the batter is set
• Delivers the pitch while not facing the batter
• Makes any pitching motion while not touching the rubber
• Unnecessarily delays the game
• Stands on or straddles the rubber without the ball, or fakes a pitch while off it
• Takes a hand off the ball after coming set, other than to pitch or throw to a base
• Drops the ball, even by accident, while touching the rubber
• Pitches during an intentional walk while the catcher is outside the catcher's box
• Pitches from the set position without coming to a complete stop

Rule 5.07 adds a few more. A pitcher may not take a second step toward home plate or reset his pivot foot during his delivery; with runners on, that is a balk. A snap throw to a base followed by the step, rather than the step followed by the throw, is a balk. And a pitcher who steps off the rubber from the windup must not go straight into the set position.

The ones you will actually see

Some items on the list are close to theoretical. The ones easiest to spot from the stands are a missing stop in the set position, a flinch of the shoulders or glove after coming set, and the ball slipping out of the glove. The intentional walk balk has become much rarer, because teams can now signal an intentional walk without throwing any pitches at all.

The penalty for a balk

The penalty in Rule 6.02(a) has two parts.

The normal outcome: the ball is dead, and each runner advances one base without risk of being put out. A runner on first goes to second, a runner on third scores, and with the bases loaded every runner moves up and one run comes home. The batter stays at the plate.

The exception: if the pitcher delivers the pitch anyway and the batter reaches first base on a hit, an error, a walk, a hit-by-pitch or otherwise, and every other runner advances at least one base, the play stands and the balk is ignored. The logic is simple: the offense already got at least what the balk would have given it, so there is no reason to take a better result away. A home run hit on a balk pitch, for example, stays a home run.

A few smaller points round it out. If the pitcher balks and also throws wildly, runners may try for extra bases beyond the one they are awarded, at their own risk. A run that scores on a balk counts as an earned run against the pitcher, just like one that scores on a wild pitch. And balks are tracked as a pitcher statistic, listed as BK on stat pages.

Why the balk rule exists

Baserunners take their leads and their jumps by reading the pitcher. If a pitcher could start toward the plate, stop and whip a throw to first, every runner would be a sitting duck. The rulebook says it directly in its comment on Rule 6.02(a): umpires should bear in mind that the purpose of the balk rule is to prevent the pitcher from deliberately deceiving the base runner, and when an umpire is in doubt, the pitcher's intent should govern.

That intent standard is why balk calls can feel subjective. Two umpires can watch the same small hitch and see it differently. It also explains a quirk: the batter can cancel a balk. If a batter steps out or otherwise causes a pitcher to interrupt his delivery, the rules say no balk should be called, and both players start over. Players on the offense are also barred from calling time or doing anything with the obvious purpose of tricking the pitcher into a balk.

Like the infield fly rule, the balk rule is really a fairness rule. It stops the defense from gaining an edge through trickery the other side cannot reasonably defend.

Newer balks: the fake-to-third move and the disengagement limit

The balk rule is old, but it has changed in the last decade and a half.

Since the 2013 season, the classic fake-to-third, throw-to-first move has been a balk. Pitchers used to be allowed to step toward third without throwing, then wheel and throw to first, usually with runners on first and third. MLB's glossary notes that this move has been ruled a balk since 2013. Faking a throw to second is still allowed.

The bigger change came in 2023 with the pitch timer. To keep pitchers from resetting the clock with endless pickoff throws, MLB limited pitchers to two disengagements per plate appearance. A disengagement is a pickoff attempt or a step off the rubber. The rules work like this:

• A pitcher gets two disengagements per plate appearance
• A third disengagement is a balk unless it produces an out, meaning the pickoff succeeds
• The count resets if a runner advances during the plate appearance
• Mound visits, injury timeouts and offensive timeouts do not count as disengagements

So a pitcher who has already thrown over twice can still try a third pickoff, but if the runner gets back safely, the runner is awarded the next base as a balk. Do not confuse this with a plain pitch timer violation: a pitcher who runs out the clock is charged an automatic ball, not a balk. For more on how the timer changed the game, see how long a baseball game lasts.

Balk examples, step by step

All of these are hypothetical situations, described the way an umpire would see them.

Example 1: no stop in the set

Runner on first, one out. The pitcher comes set, but his hands barely pause before he goes to the plate. The umpire calls a balk. The ball is dead, the runner goes to second, and the batter stays at the plate. If the pitch had been a fly ball out, it would be wiped away, because the batter did not reach base.

Example 2: the slip with the bases loaded

Bases loaded, two outs. The pitcher is on the rubber and the ball slips out of his glove onto the mound. That is a balk even though it was an accident. Every runner moves up one base, the runner from third scores, and it goes in the books as an earned run.

Example 3: the play stands

Runner on first. The pitcher flinches during his set, the umpire points and calls a balk, but the pitcher delivers anyway. The batter lines a single to right and the runner races to third. The batter reached first and the runner advanced at least one base, so the play stands: runners on first and third, and the balk is ignored.

Example 4: the failed third pickoff

Runner on first. The pitcher throws over once, then steps off the rubber, using both disengagements. On his next move he throws to first again and the runner dives back safely. Because the third disengagement did not produce an out, it is a balk, and the runner is awarded second base.

Common balk misconceptions

A few things fans often get wrong:

• A balk is not possible with the bases empty; the same act is an illegal pitch and a ball
• Not every flinch is automatically a balk; the umpire judges whether the motion was part of a pitch or a move meant to deceive
• A pitcher can legally fake a throw to second base
• A pitcher who properly steps back off the rubber with his pivot foot is treated as an infielder, so the balk items about faking throws, which apply while he is touching the rubber, no longer cover him (the step-off does count toward his two disengagements)
• An accidental balk is still a balk; the dropped ball case proves intent is not required for every item on the list

Balk quick reference

The short version to keep in mind next time an umpire points at the mound:

• What it is: an illegal act by the pitcher with at least one runner on base
• Penalty: dead ball, every runner advances one base, batter stays up
• Exception: if the pitch is delivered and the batter reaches first and all runners move up at least one base, the play stands
• No runners on: the same act is an illegal pitch, counted as a ball
• Since 2013: fake to third, throw to first is a balk
• Since 2023: a third disengagement in one plate appearance is a balk unless it gets an out
• Purpose: to stop pitchers from deceiving runners

A balk that scores a run hurts the pitcher's numbers too. Our guide to ERA in baseball explains how those runs are counted.