OBR 6.02. (a) 7 – It is a balk when the pitcher makes any motion naturally associated with his pitch while he’s not touching the pitcher’s plate.
Thus, it must be adjudged whether his throwing motion is “naturally associated with his pitch”. This most commonly occurs with a suicide squeeze, and the pitcher steps off quickly and then throws home to retire the runner. This is generally considered NOT a natural pitching motion as all parties involved are usually aware that it is an attempt to throw out the runner from third. However, if the pitcher steps back, but then throws in a manner similar to his pitching motion, it could be called a balk.