There are two legal pitching positions, the Windup Position and the Set Position, and either position may be used at any time.
Pitchers shall take signs from the catcher while in contact with the pitcher’s plate.
Rule 5.07(a) Comment (Rule 8.01 Comment): Pitchers may disengage the rubber after taking their signs but may not step quickly onto the rubber and pitch. This may be judged a quick pitch by the umpire. When the pitcher disengages the rubber, he must drop his hands to his sides. Pitchers will not be allowed to disengage the rubber after taking each sign.
(2) The Set Position
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. From such Set Position he may deliver the ball to the batter, throw to a base or step backward off the pitcher’s plate with his pivot foot. Before assuming Set Position, the pitcher may elect to make any natural preliminary motion such as that known as “the stretch.” But if he so elects, he shall come to Set Position before delivering the ball to the batter. After assuming Set Position, any natural motion associated with his delivery of the ball to the batter commits him to the pitch without alteration or interruption. Preparatory to coming to a set position, the pitcher shall have one hand on his side; from this position he shall go to his set position as defined in Rule 5.07(a)(2) (Rule 8.01(b)) without interruption and in one continuous motion. The pitcher, following his stretch, must (a) hold the ball in both hands in front of his body and (b) come to a complete stop.
This must be enforced. Umpires should watch this closely. Pitchers are constantly attempting to “beat the rule” in their efforts to hold runners on bases and in cases where the pitcher fails to make a complete “stop” called for in the rules, the umpire should immediately call a “Balk.”
Rule 5.07(a)(2) Comment (Rule 8.01(b) Comment): With no runners on base, the pitcher is not required to come to a complete stop when using the Set Position. If, however, in the umpire’s judgment, a pitcher delivers the ball in a deliberate effort to catch the batter off guard, this delivery shall be deemed a quick pitch, for which the penalty is a ball. See Rule 6.02(a)(5) Comment (Rule 8.05(e) Comment).