A balk occurs when a pitcher makes an illegal motion on the mound that the umpire deems to be deceitful to the runner(s). As a result, any men on base are awarded the next base, and the pitch (if it was thrown in the first place) is waved off for a dead ball.
According to the official rules of the MLB, there are 13 ways a pitcher can balk. The ways a pitcher can balk ranges from the way they come to their set position and all the way through how they deliver the ball to home.
(d) Official Baseball Rule 6.02(a)(3) requires the pitcher, while touching the pitcher’s plate, to step directly toward a base before throwing to that base. If a pitcher turns or spins off of his free foot without actually stepping, or if he turns his body and throws before stepping, it is a balk.
If no runners are on base and the pitcher commits an otherwise balkable action, there generally is no penalty. However, delivering a quick return or pitching while off the rubber (which constitute balks when runners are on base) results in a ball being called with the bases empty.
The rules state that a pitcher must step toward the base he throws to. It doesn’t matter if you’re set or not. If you’re on the rubber, that makes you a pitcher and you must step before throwing.
Rule 8.05(e) Comment: A quick pitch is an illegal pitch. Umpires will judge a quick pitch as one delivered before the batter is reasonably set in the batter’s box. With runners on base the penalty is a balk; with no runners on base, it is a ball. The quick pitch is dangerous and should not be permitted.
If the pitcher drops the ball while in contact with the rubber and the ball does not break the plane of the foul line, that is a balk. If the ball crosses the foul line, that is a wild pitch and the ball remains live.
To avoid a balk call, be sure that you step toward first base when you throw. You must “disengage from the rubber” before throwing to first base. For RHPs this means you move your back foot [the one touching the rubber] first.
Once a pitcher steps off the pitching rubber, they are considered an infielder and they are allowed to do whatever they want. If they want to fake a throw to first base after stepping off the rubber, they are able to do that without breaking any rules.
A pitcher can not feint a throw to first base.
One of the more uncommon, but still exciting, ways to end a baseball game is by the pitcher making one costly mistake with a balk. What is a balk off? A “balk-off”, also known as a “walk-off balk”, refers to a baseball team winning a game because of a balk on the pitcher.
However, if in the umpire’s judgment, the pitcher has thrown this ball to the shortstop in this case – legally or not, in such a manner that delays the game, then a BALK shall be called on the pitcher and ALL runners advance one base.
When a balk is made on a pitch that is a fourth ball it shall be ruled the same as when the batter hits a balk pitch and is safe on a hit or error, provided all runners advance at least one base on the play.
Baulk is a British variant of balk. In British publications, balk and baulk are used interchangeably, and both spellings appear about equally often. Canadian writers favor balk, and Australians favor baulk.
It’s not a balk because he’s not in his set position yet.
From the windup position, any natural movement associated with delivering the ball commits the pitcher to pitching the ball in a single, continuous motion. This includes any motion by hand, arm, or legs. Failing to deliver the pitch is a balk (with runners on base).
With runners on base, call a balk. With no runners on base there is no infraction and no penalty. If a pitcher swings any part of the free foot past the back edge of the pitcher’s plate, the pitcher is required to pitch to the batter, except to throw to second base on a pick-off play.
A quick pitch is an illegal pitch. Umpires will judge a quick pitch as one delivered before the batter is reasonably set in the batter’s box. With runners on base the penalty is a balk; with no runners on base, it is a ball. The quick pitch is dangerous and should not be permitted.
The pitcher may fake a throw to second or third base from the rubber, but not to first base. This may be done from the windup or the set position. (You do not have to step off the rubber to fake to 2nd or 3rd.
It can become monotonous when a pitcher makes throw after throw after throw to first base in a vain attempt to pick off a pesky baserunner. This rule will limit pitchers to just two “step offs” or pickoff attempts per plate appearance.