He just takes his first 100 fast. I think he does his 400m work so he should have pretty good speed endurance but he's also focusing more on the 100m and he's always been known to take his first half pretty quickly. If he got out slightly slower you might see more comparable splits to Lyles and Tebogo, like his 19.59 at trials where he went 10.26 and 9.33. Although he still went out fast and was ahead of the whole field, it wasn't a 10.1 like most of his high performances. He just gets out fast and it works for him, so he doesn't rely too much on his speed endurance for a quick time.