re: Mainieri says hitting coach is overrated

If you get a kid who can hit exceptionally well out of HS, leave him alone until he hits a slump, then you try to help him fix his swing (if it needs fixing) or just mentally get out of it. Sometimes it is a physical thing in your swing and not just in your head. Bad habits do develop and that's what the coach is for.

Some hitters have great raw power and bat speed, but they have a mechanical flaw that leaves a hole that pitchers expose in their swing. Hitting coaches can turn those guys from a Jordan Mayer type hitter into a Nick Stavinoha type hitter.

Some hitters are just not selective enough at the plate. Approach can be taught (see SB), but some players are still too bullheaded to listen. However, the few that do learn an approach and perfect it help the whole team out even if they're a mediocre talent. (i.e. Sal Intagliata, Goldstein)