Success ought to breed success, but it doesn't always work that way. In fact, success has no greater danger than itself. When Roy Tarpley entered the National Basketball Association, it was assumed that Dallas could build a team around him. Experts say he would have made the American "dream team" for the Barcelona Olympics if he had fulfilled his obvious talent. Instead, when he should have been at the top of his game, he was not even in the NBA. "My problem, "Tarp…