I’m wondering has there ever been anyone - male or female - who held the 100m, 200m and 400m world records - or the Imperial equivalents - simultaneously or even over the course of a career?
I think Betty Cuthbert may have set world records at the three distances, but a North Korean is said to have actually run faster at 400m (sub-52) around 1964 Tokyo when Cuthbert returned to win the 400m in 52.0-ish.
Betty is certainly the only athlete - male or female - to have won Olympic gold at the three distances (100, 200m as well as 4x1 in 1956 Melbourne).
Herb McKenley must have been there or thereabouts across the three distances.
Tommie Smith I think actually did hold all three WRs, not sure about concurrently and maybe his 100WR was hand-timed so he would have been one of a number who collectively held the WR.
I don’t remember Tommy having a 100m WR. If he did, it might have been at 10.0ht. He did have 200m,220y straight ht, 200m, 220y turn ht, and 400m,440y ht, and 200m E along the way.