With runners on base, after the pitcher goes into his wind-up or makes any movement associated with delivering the ball to home plate, the pitcher must not interrupt his motion or the umpire can call a balk. A balk occurs when a pitcher tries to catch a runner off base with a pick-off throw after he has started his delivery to the batter.
To avoid balking, a pitcher standing on the rubber cannot raise either foot from the ground toward home plate unless he is starting his delivery. The umpire also calls a balk if the pitcher drops the ball while trying to deliver a pitch. A balk does not occur if the pitcher is in his set position when he throws to a base.
Deceptiveness is one of the keys to an effective pick-off throw. However, you can't be so deceptive that the umpire calls you for a balk. You can, however, avoid balking while attempting a pick-off at first by doing the following:
- When you are in the set position, take the sign from your catcher with your foot on the rubber and your hands visibly separated.
- After you have your sign, bring your hands together and pause one full second before going into your delivery.
- If you swing your striding foot past the rear portion of the pitching rubber, you must deliver a pitch.
- Move only your head while in the set position. If you shrug your shoulders or move your legs or hands, the umpire can nail you for a balk.
- If you make any motion toward a base, throw to it. You must complete any movement you start without interruption until you are in the set position.
- Always step directly toward the bag you are throwing to. You may step and fake a throw to second or third, but you cannot fake a throw to first without first stepping off the rubber.
- If you want to move out of the set position without incurring a balk, step off the rubber.
- Never make a pitching motion unless you have the ball.
- Don't drop the ball during your delivery.
"It may sound funny, but don't even scratch your nose or wipe your mouth when you are on the rubber with a runner on first. I've seen guys called for balks for doing just those things. You're concentrating so hard on the hitter, something itches, and you just do the natural thing. Just make sure you step off the rubber first." — Bill "Spaceman" Lee, former Boston Red Sox and Montreal Expos pitcher
