What Is a Balk in Baseball?

An umpire will call a balk when a pitcher tries to intentionally deceive the hitter or base runners. A balk in baseball is an illegal act that can only occur when runners are on base. When a balk is called, all runners are able to advance one base.

A balk can only occur in baseball and there is no such rule for fastpitch softball.

What Constitutes a Balk by a Pitcher?

There are several actions a pitcher can make that will result in a balk.

Since there is some gray area when it comes to what constitutes a balk, an umpire is instructed to rule a balk called based on the intent of the pitcher. Certain movements by the pitcher are considered deceptive and will be called a balk.

As a pitcher, you must adhere to certain rules when it comes to pick-off throws to bases and when you actually start the process of delivering the ball to the catcher. 

The playing status of the pitcher being an “infielder” instead of a “pitcher” is defined by whether or not their pivot foot is in the pitching position on the rubber. To become a “fielder”, the pitcher must step off the rubber with their pivot foot.

The first rule for any pitcher to remember is that they must come to a complete stop after he gets the sign, but before he pitches home. This is called the “set position“.

The set position is indicated when the pitcher faces the batter with his pivot foot in contact with the pitching rubber.

The pitcher must hold the ball in both hands in front of his body and come to a complete stop. From the set position the pitcher may deliver the ball to the batter, throw to a base, or step off the rubber with his pivot foot.

Balks on Pick-Off Moves

1. Any movement the umpire deems as deceptive will be called a balk.
2. If a pitcher starts his motion and his foot crosses his knee, the pitcher has to throw home. On pick-off attempts, the foot must stay straight up and down.
3. If a ball falls to the ground, intentionally or not, a balk will be called.
4. Because left-handed pitchers face first base, where most pick-off attempts go, they have an added advantage to picking off the runner. This is why a pitcher’s foot must go in the general direction he is throwing.
   • Umpires generally use an imaginary 45-degree angle to judge the deceptiveness of a left-handed pitcher’s pick-off attempts.
   • If you are pitching home your foot must land on the home plate side of the angle.
   • If you are performing a pick-off move, the foot must land on the first base side.
   • This rule prevents a left-handed pitcher from intending to pitch home but notice the runner attempting to steal second and then desperately tossing the ball to first base.
5. When a right-handed pitcher comes set they cannot move their shoulders to view first base. This will be viewed as a pick-off attempt and they will have to throw to first. They can only turn their head unless they step back off the pitching rubber.
6. If a pitcher makes a pick-off movement to any base and does not throw the baseball, it will be called a balk. The pitcher must step off of the rubber if they intend on not throwing the ball to the base.

Balks on Pitches

1. The pitch is delivered without the pitcher ever coming to a discernible stop in the set position.
2. The pitcher makes his natural pitching motion but fails to pitch the ball.
3. When a runner attempts to steal as the pitcher is making his motion home, the pitcher must continue their pitch home. A balk will be called if they stop their motion to the plate to attempt a pick-off move.
4. The pitcher fakes a pitch without the ball.
5. The pitcher removes one hand from the ball after coming to the set position.

Illegal Pitcher Movements With No Runners On Base

If a pitcher commits an illegal balk act described above with no runners on base, he will instead be called for an illegal pitch. This means an automatic ball will be added to the pitcher’s count unless the batter reaches first base by hit, error or being hit by the pitch.

You can view rule 8.05 in MLB’s official rulebook for additional information about balks in baseball. View our baseball FAQ page for other information.