[mbyron]

I think that I would talk to the both coaches together. I would tell them that there was nothing in the rules to prevent the home players from taking BP before an at-bat, but that it certainly appears to be unfair to the visitors. I would tell them that if the home players continued taking this advantage, I would report the situation to my assignor, who would likely take the question to the state association for a ruling. Then I'd say, let's play ball.

I think the visitors have a legitimate complaint here, and I'd want to find some way to tell the home coach that I think it's legitimate, but without making up rules to do so. I think this little speech might do the trick.

Since it's not violating any rule in the rule book or any state ruling that I'm aware of, I would do nothing else on the field. You might try to sell it as unsportsmanlike, but I wouldn't.