Greatest swimmers always put their attention on improving their time and not on reaching other athletes. And in the end, that's the matter, once you've done the time, you've no more someone to beat.
I think 95% of results is due to the athlete, due to his psyco-fisiological maturity, and 5% to coach, but this 5% matters a lot. The coach and the athlete are like a strong box (athlete) and his password (coach). Without the other, the first cannot reach his purpose