At least one coach told son that he wants to see him in a game situation, and if he could plan that, he could plan it to be a game where things don't go well. He said "I want to see how you react to that, do you hang your head, do you stay focused, etc? I know you can pitch when things are going well. How do you handle it when things aren't?"
I think the idea is a good one — it makes a kid reflect on his performance and learn to think about what goes wrong, without hopefully dumping on himself.