Intent of the Balk. The balk is meant to prevent the pitcher from illegally deceiving the base runner. The pitcher will occasionally try to catch a runner off guard in order to prevent possibilities such as stealing a base or getting too much of a lead off a base.
Penalty. In all cases, the penalty for a balk is a single base awarded to all runners (but not the batter). This penalty is always charged to the pitcher.
Quick list . Below is a quick list of 19 ways to balk. Of course, for a more complete explanation get the Baseball Field Guide, available at Amazon and other booksellers.
1. Interrupt his pitching motion, perhaps the most common way to balk.
2. Fail to come to a complete stop during the set position.
3. Fail to step toward and ahead of a throw.
4. Fail to have both hands on the ball once he’s in the set position.
5. Pitch while his pivot foot is not touching the rubber.
6. Pitch while his head is not facing the batter.
7. Fake a throw to first base. Once he makes a motion to throw to first base he must complete it.
8. Fake or complete a throw to an unoccupied base.
9. Make a pitching motion without completing the pitch.
10. Make a quick pitch. A pitcher must not pitch before the batter is ready.
11. Fake a pitch.
12. Drop the ball while on the rubber.
13. Disengage the rubber improperly.
14. Delay of game. This is a judgement call by the umpire, if he believes a pitcher is intentionally delaying the game.
15. Come to the set position twice.
16. Change from one pitching position to the other without disengaging the rubber.
17. Pitch using a tampered ball, unless the team at bat chooses to accept the play that ensued.
Balks caused by other players:
18. Catcher or other player tries to block a runner attempting to score from third base by stealing home, or during a squeeze play.
19. Catcher outside the catcher’s box during an intentional walk. The catcher must be in his box at the beginning of a pitch-out.