More than any other American sport, baseball is a game where mental focus is as important as speed or strength. The challenge for coaches has long been how to get top athletes to exercise the muscle between their ears. One of the leaders in that area was Harvey Dorfman, who is considered the father of sports psychology. He had a long career helping some of the world’s most famous baseball players — Roy Halladay, Alex Rodriguez, Greg Maddux among them — learn to think more rigorously about the game. Dorfman died earlier this year at his home in Brevard, North Carolina.