Gaining Ground toward 2nd

[umpstu]

23 minutes ago, Jimurray said:

Where the trail/pivot foot goes doesn't matter. As per Jim Evans at a clinic, a legal step toward a base that can be feinted to is a legal disengage. Either Nelson perceived no step/clearance to 2B or we don't know his reason for the balk. 

9-1-b-3) When the pitcher starts the delivery from the set position and the entire free foot or any part of the stride leg breaks the plane of the back edge of the pitcher’s rubber, the pitcher is committed to throw or feint a motion toward second base or pitch to home plate

To me it looks as if his non pivot foot goes behind the rubber and he throws to third.

[Jimurray]

48 minutes ago, umpstu said:

9-1-b-3) When the pitcher starts the delivery from the set position and the entire free foot or any part of the stride leg breaks the plane of the back edge of the pitcher’s rubber, the pitcher is committed to throw or feint a motion toward second base or pitch to home plate

To me it looks as if his non pivot foot goes behind the rubber and he throws to third.

That would be breaking the plane while still in the air. The pitcher was committed in this case to feint which he did with a feint to 2B with, as you say, a step clear of the rubber.  He then became an infielder. But you were talking about the pivot foot. What has changed your mind regarding the pivot foot. .In my mind I don't know why the balk was called by rule but maybe we don't have enough info which will probably not be cleared up by MLB. There is plenty of that going around as exemplified by Miller explaining that Eddings didn't know the IFF had been called when calling a force out yet a second later realizing it was not a force because he now telepathically realized it was an IFF and he effed up so he called time. We all eff up. MLB less than us but they do. Do not rationalize their eff ups. Learn from them or if they result from current MLB umps not knowing the rules consider maybe that some of them have not taken umpire Doug Harvey's advise.