[JRutledge]

This is a pregame issue. Obviously if no one is on base, both of you can have this call. But this is an issue that you discuss in the pregame because some want to do all the work themselves, and if that is what they want, let them have it. Especically if you have a PU that wants all the calls. Some guys get anal about it. So discuss it in pregame first.

But according to the manuals, usually this is either on of the umpires call. The reality is to get it right. Obstruction is a delayed dead ball situation, so you can see the play develop a little bit before you actually call obstruction. But I see not reason as a BU you could not have this call, you are looking there.