although there are doubters -- notably '84 olympic gold medalist rowdy gaines , now a television commentator -- that the world championships and this week 's strong performances at the u.s. swimming spring nationals are indicative of olympic success , many coaches such as quick see the united states at the brink of greatness. ; 'you just do n't know ' ; `` a 16 - , 17-year-old girl who set the world on fire in january of '91 could be over the hill by the time march -lrb- date of the olympic trials -rrb- rolls around in '92 , '' gaines said .