Men's SP - Illegal vs. No pitch

[Robmoz]

Originally posted by chuck chopper
In the Preliminary the pitcher can't start unless he gets up on the rubber. So if you can tell they are not on the rubber, keep your hand up & don't let them pitch. If he/she asks what the hold up is say "get on the rubber, then you can pitch"

Ok, agreed the pitcher cannot start unless on the rubber but I only hold up a hand if the batter requests or if I am not ready, if the pitcher delivers off the rubber why should I declare 'no pitch'? I agree with Mike that it is simply a DDB illegal pitch. Am I missing something else here or building a mountain?