And sometimes practice doesn't matter much at all. Some people are just great at what they do.

Charles Barkley (well-known NBA future Hall of Famer) was well known for being a slacker at practice. He hated it.

Randy Moss (well-known NFL future Hall of Famer) was also one of the laziest players, poor team player, and hated practice.

Mark Spitz (7-time gold medal winning swimmer) apparently was particularly uninterested in practice, put in the bare minimum yet reaped huge rewards.