in other events we see swimmers cruising through prelims and semifinals, They'll hold back, not go all out, let up when it's in the bag, do enough to move on, saving their big swim for the finals. You won't see this in the 50, swimmers have to go for it, they have to swim lights out, the 50 is too short to hold back, no one wants to hold back and miss out on advancing.
in other events we see swimmers cruising through prelims and semifinals, They'll hold back, not go all out, let up when it's in the bag, do enough to move on, saving their big swim for the finals. You won't see this in the 50, swimmers have to go for it, they have to swim lights out, the 50 is too short to hold back, no one wants to hold back and miss out on advancing.