Can stalling your delivery be cause for a balk?

Question

Watching the 2016 AL Wild Card game between Toronto and Baltimore (that Edwin Encarnacion won with a walk-off), and I'm seeing what might be considered a balk, but I'm not sure why it's not.

Roberto Osuna pitched in relief in this game. His delivery was smooth and normal, like most pitchers. However, he altered his delivery in only certain situations (2-strike count, looking to put the batter away). I'm not sure he even did it more than once or twice.

Here is a clip of that game and the delivery in question.

Now, with Daisuke Matsuzaka, I can understand the argument that it wouldn't be called as a balk because his hitch is part of his delivery. But wouldn't hitching in your delivery as an exception be considered as intentionally trying to deceive the batter?

Answer 1

The rule is that the pitcher must continue his delivery once he has swung his leg past the pitching rubber. See this from mlb.com:

Once a pitcher has swung his free leg back past the pitching rubber while in the process of his leg kick, he must then deliver the ball to the plate or to second base on a pick-off attempt.

I don’t think Osuna does cross the rubber with the free leg during the hitch, so it’s legal. Just changing the timing.

Note that it would not be called a balk with no runners on base. It could however be called an illegal pitch (with the same rules applying; it would simply be an automatic ball regardless of the result of the pitch unless the batter reached base safely as a result of the pitch.)