Answer
The "sub-10, 20, 31, 44" refers to Wayde van Niekerk's remarkable achievement in track and field events. Specifically, he became the first sprinter to accomplish the feat of running the 100 meters in under 10 seconds (sub-10), the 200 meters in under 20 seconds (sub-20), the 300 meters in under 31 seconds (sub-31), and the 400 meters in under 44 seconds (sub-44).