I need help on what I think is a balk.
With a runner on first, a right handed pitcher lifts his knee straight up, then drop steps directly toward first base and picks off the runner. Is this a balk?

I am going to try my hand at this one, if my understanding is correct, as long as his plant foot hasen't broke the plane of his pivot foot he is OK. Please correct me if I am wrong...(which would be done without asking of course)

BALK

balk
 

Could you tell me why you believe this to be a balk? I think because the pitcher must step directly towards the base to which he throws.

Balk, and even the guys who seldom call balks would call that one. A right-hander does not throw to 1B by lifting his left knee straight up. That's a motion toward home, part of a natural delivery to the plate. Once he does that, he cannot then step toward 1B and attempt a pickoff, no matter how he contorts to do it. He's committed to make a pitch.

Now with a runner on 3B, "straight up" as you describe, might still allow a throw to 3B, as long as the leg movement remains legal (doesn't cross the plane).