That's a strong vestibular system. We actually try to train this in fast bowlers as well.Here's an example of what I mean (timestamped)
Most folks lunge forward to gain greater speed when pursued, but Will stays relatively upright and still gets away. This affords him much greater balance.
It makes him look cocky, and of course we know after listening to him speak, that he's a very humble, grounded young fella without an ounce of arrogance in him.