One of the common quotes in training for track is that "the only way to run faster is to run faster." This is in reference to overspeed training for running.
We use the same concept with bat speed. In stead of training with our gamer and a weighted bat, we also include a light weight bat or broomstick that we can swing considerably faster then our gamer. This teaches our body how to perform the exact same movement alot faster so that when we have a bat in our hands our muscles "know" how to more with more speed.
Not sure if that answers any questions or simply raises more...
Coach Dan
www.baseballstrength.com