Several years ago doing a ASA 12u B tournament had a batter strike out swing. I gave a strike signal and said strike thee loud enough for the catcher and hitter to hear. I stepped back cleared my indicator, next batter stepped in the batter's box hit the next pitch and made it safe on first base.

D coach came up and said the runner on first was the one that you just called out. I looked at his score book, checked my line up card sure enough it was the same batter. I had BOO.

O coach was very upset and wanted to call the UIC over. UIC came and I told both of them I gave the strike signal and told the catcher and batter that was strike three. It was not my responsibly to make sure the correct batter was coming to bat. I'm here to umpire not to coach. UIC agreed, BOO play on.

Even at lower level rec ball I will tell the batter several times strike three but at what point is it the coaches responsibly and not yours.