When does a RHP commit?

[IntlBlue]

Here's how I've explained this move to an objecting coach:

"Skip, when your pitcher lifted his foot, and didn't immediately go to first, which way did his knee go?" Answer MUST be "toward third base". Then I tell the coach "welllllll, after moving toward third, then he MUST disengage the rubber before he can turn to throw to first" (the ole 3-1 move)"and he didn't, so it's a balk." I've never (in 17 years) had a coach argue further.

It has worked just fine for me in the past. Hope this helps.