If the player lines up two yards over the start line in sprints and you do not correct him, do not jump his butt when he does it in the game . …If you do not correct the offensive lineman in practice for holding, do not bitch at the official for calling it in the game. If you accept it, you should expect it in the games, and that is on the coach.
– Chip Kelly
Source: The Tao of Chip Kelly by Mark Saltveit.