Stubborn Partner – what can you do?

[AtlUmpSteve]

Relating to this original post, PU saw "contact with F3 and is knocked off stride". OBS can be called by PU, and if he observes that BU has failed to do it, he should. This one sounds obvious, and the obvious call can't be ignored.

Gray area, I agree; don't start making them from your position. Black and white, call it every time; maybe hesitate, and don't bother if BU does it, but do not let it be uncalled.