Rule sets / OBR / High Set Position Balk
High Set Position Balk
The pitcher must hold the ball in both hands in front of his body when coming to a complete stop in the set position. If his hands are above the top of his head, it is a balk.
If there is a runner, or runners, it is a balk when the pitcher delivers the pitch from Set Position without coming to a stop.
Set Position shall be indicated by the pitcher when he stands facing the batter with his pivot foot in contact with, and his other foot in front of, the pitcher's plate, holding the ball in both hands in front of his body and coming to a complete stop.
MLB Umpire Development Manual Authoritative interpretation
Rule 5.07(a)(2) stipulates that the pitcher, following his stretch, must hold the ball in both hands in front of his body when coming to a complete stop. The professional interpretation of "in front of his body" is that the hands must be below the top of the pitcher's head. If a pitcher comes to a complete stop with his hands above the top of his head, he shall be charged with a balk.