Balk?

[David Van Milligen]

"Sit 2- If F1 disengaged from the mound he can fake towards first. If he didn't he must throw there."

I am not looking for a fight, only an explanation I can understand.
The rule book explaines how to legally step off the rubber. It does not tell you how to legally "disengage the rubber". If the RHP feints a throw to third and he is no longer in contact with the rubber, does that make him a fielder, or is he still considered the pitcher, because he has not steped off the back of the rubber with his pivot foot. If it makes him a fielder then most throws attempting to pick off a runner at third would come after he disengaged the rubber, so if they went into dead ball territory runners would get two bases. I do not think they can have it both ways.