After winning four gold medals and setting four world records in the 1976 Olympics, champion backstroker John Naber revealed that before that season started, he had calculated the time he was reasonably sure could win each race (knowing that it would be faster than anyone had gone before). Then he subtracted that time from his current best, ending up with the number of seconds he’d need to improve to hit that target time. Then he divided that time increment by the number of swim practices remaining before the competition. The resulting small fraction of a second represented how much he needed to improve during each remaining swim workout.