Does a pitcher have to have both feet touching the rubber?
No, from the MLB rule book.. 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. (a) The Windup Position. The pitcher shall stand facing the batter, his pivot foot in contact with the pitcher’s plate and the other foot free. From this position any natural movement associated with his delivery of the ball to the batter commits him to the pitch without interruption or alteration. He shall not raise either foot from the ground, except that in his actual delivery of the ball to the batter, he may take one step backward, and one step forward with his free foot. When a pitcher holds the ball with both hands in front of his body, with his pivot foot in contact with the pitcher’s plate and his other foot free, he will