One interesting thought - can anyone point to a character who has improved notably from training?

I can't think of a thread about a "well trained" player. My own experience is that highly capable players are identifiable pretty quickly. I can train players to keep up, but can a player go from average 6.5 to 8s? Lots of noise in that, many managers probably don't keep players long enough to develop, or don't have a plan for training or tactics.