Watching Friday 's race -- which combines 50 meters each of butterfly , backstroke , breaststroke and freestyle -- gives a glimpse into this rivalry .
It was the most compelling event over the first six days of this meet .
Watching Friday 's race -- which combines 50 meters each of butterfly , backstroke , breaststroke and freestyle -- gives a glimpse into this rivalry because it was the most compelling event over the first six days of this meet .