What is a balk? The balk rule, explained for umpires

What does the balk rule say?

The Official Baseball Rules define a balk as an illegal act by the pitcher with a runner or runners on base, entitling all runners to advance one base. Rule 6.02(a) then lists thirteen acts that are balks when there is a runner on base.

The thirteen fall into four groups. The first is starting and stopping: the pitcher makes a motion naturally associated with his pitch and does not deliver it, makes that motion while off the rubber, feints a pitch while off the rubber, takes a hand off the ball after coming to a legal pitching position, lets the ball slip or fall while touching the rubber, or delivers from the Set Position without coming to a stop.

The second is throws to bases. While touching the rubber, the pitcher feints a throw to first or third and does not complete it, throws without first stepping directly toward the base, or throws or feints to an unoccupied base when he is not making a play.

The third is the pitch itself: an illegal pitch, a pitch delivered while not facing the batter, or a pitch on an intentional base on balls while the catcher is out of the catcher's box. The fourth is delay and standing in without the ball: the pitcher unnecessarily delays the game, or stands on or astride the rubber without the ball.

Behind all thirteen sits one purpose. The comment to Rule 6.02(a) says the balk rule exists to prevent the pitcher from deliberately deceiving the base runner, and that when the umpire is in doubt, the pitcher's intent should govern. Straddling the rubber without the ball is always read as intent to deceive.

What happens when a balk is called?

On a balk the ball is dead and each runner advances one base without liability to be put out. That is the penalty in Rule 6.02(a), and Rule 5.06(c)(3) lists the balk among the plays on which the ball becomes dead and runners advance.

The penalty has one exception. If the batter reaches first on a hit, an error, a base on balls, a hit batter or otherwise, and every other runner advances at least one base, the play proceeds without reference to the balk. The offense keeps whatever it gained.

Two approved rulings finish the picture. If the pitcher balks and throws wild, to a base or to the plate, runners may advance past the base they are entitled to, at their own risk. And a runner who misses the first base he is advancing to and is called out on appeal is treated as having advanced one base for the purpose of the exception.

What is the difference between a balk and an illegal pitch?

An illegal pitch is a pitch delivered when the pitcher's pivot foot is not in contact with the rubber, or a quick return pitch. With runners on base an illegal pitch is a balk. With the bases empty, Rule 6.02(b) makes it a ball, unless the batter reaches first on a hit, an error, a base on balls, a hit batter or otherwise.

The quick pitch follows the same split. The comment to Rule 6.02(a)(5) says umpires judge a quick pitch as one delivered before the batter is reasonably set in the box. With runners on, the penalty is a balk; with no one on, it is a ball.

A ball that slips out of the pitcher's hand works the same way. With runners on base it is a balk under 6.02(a)(11). With the bases empty, the comment to 6.02(b) makes it a ball if it crosses the foul line and no pitch if it does not.

What does a legal Set Position look like?

A legal Set Position, under Rule 5.07(a)(2), has the pitcher facing the batter with his pivot foot in contact with the rubber and his other foot in front of it, holding the ball in both hands in front of his body and coming to a complete stop. From there he may pitch, throw to a base, or step back off the rubber with his pivot foot.

The rulebook is unusually blunt about the stop. It says the stop must be enforced, that pitchers are constantly attempting to beat the rule, and that when a pitcher fails to make a complete stop the umpire should immediately call a balk.

With a runner on base, a pitcher standing with his pivot foot parallel to the rubber and his other foot in front of it is presumed to be in the Set Position. He can pitch from the Windup instead only by telling the umpire before the at-bat, or within it after an offensive substitution or a runner's advance.

The Windup has its own traps. The comment to 5.07(a) bars the pitcher from stepping toward the plate twice, or resetting his pivot foot, during his delivery; with runners on, that is a balk. The comment to 5.07(a)(1) requires a pitcher leaving the rubber from the Windup to step off with his pivot foot first, and makes it a balk if he goes into a set or stretch from there.

Which pickoff moves are legal?

A pickoff throw is legal when the pitcher, while touching the rubber, steps directly toward the base before throwing to it. The comment to Rule 6.02(a)(3) says that spinning off the free foot without actually stepping, or turning the body and throwing before stepping, is a balk.

Once he steps toward a base, the pitcher is required to throw there, except to second base. Feinting a throw to second is legal. Feinting a throw to first or third and not completing it is a balk under 6.02(a)(2), so with runners on first and third, stepping toward third to bluff the runner and then turning to throw to first is a balk. The comment to 6.02(a)(3) uses that exact play as its example.

With a runner on first, the comment to 6.02(a) allows a complete turn, without hesitating toward first, and a throw to second. That is not a throw to an unoccupied base. For any other throw to an empty base, the comment to 6.02(a)(4) asks whether the runner on the previous base showed an intent to advance to it.

The free foot matters too. Under the comment to 6.02(a)(1), a pitcher who swings his free foot past the back edge of the rubber must pitch, except that he may still throw to second on a pickoff.

How should an umpire call a balk?

Call it the moment you see it, out loud, and point at the pitcher. The rulebook asks for an immediate call on a missed stop, and a late call leaves both dugouts guessing what you saw. If the manager asks, say what it was in a few words: no stop, no step, a hand off the ball.

Calling the balk is not the same as calling Time. If the pitcher delivers anyway, watch the pitch through. The exception in the penalty means the result decides the ruling: if the batter reaches first and every runner moves up at least a base, the play stands; if not, kill it and award one base to each runner.

Baseline the pitcher before you judge him. In the first innings with a runner on, watch how long he holds the ball at the stop and where his hands come to rest. A balk on the stop is easiest to see as a change from what that pitcher has been doing all game.

Watch the feet for pickoffs and the hands for the stop. The step decides a pickoff balk, so the free foot has to move toward the base before the ball leaves. The stop decides a set balk, so the hands have to come to rest before the pitch begins. Trying to watch everything at once is how both get missed.

College and high school games play their own balk rules. The NCAA book, for example, makes it a balk for a pitcher without the ball to stand on any part of the dirt circle during a hidden ball play (NCAA 9-3-f), where the OBR needs him on or astride the rubber. The Veritas pro vs college rule differences table sets the two codes side by side.