Balk or what...help with ruling??

OK, great baseball minds, especially any umps out there. Here is the situation. Runner on 3rd and RHP on mound. The pitcher stretches out , foot against the rubber and stretched out (pre set position) with glove on knee and ball in his hand behind his back looking at his catcher. You can picture what I mean...normal stance before coming set. The runner on 3rd breaks for home and nstead of coming set the pitcher throws the ball directly to the catcher. I thought the runner beat the ball but ump called him out. My argument was that was a balk because the pitcher was throwing to an unoccupied base. Unique situation that I have never seen before so what is the proper call here? Does the pitcher have to come set before he can throw to the catcher.....can he do as described above?? I honestly don't know. Thanks in advance.

 

It IS a balk..............

Pitcher should have stepped back off rubber then thrown to home.

 

Bingo

 

that's what I would think