Conversation so far:
Where was Mike Piazza' childhood years spent?
Mike Piazza was born in Norristown, Pennsylvania
where else did Mike Piazza grow up in besides Norristown?
Mike Piazza grew up in Phoenixville, Pennsylvania
what is interesting about Mike Piazza's childhood?
When he was 12, Mike Piazza received personal instruction in his backyard batting cage from Ted Williams
What was the outcome of Mike Piazza's bat boy service?

Question: what other training did he receive?
Self-contained rewrite: what other training did Mike Piazza receive besides training from Ted Williams?