Could you expand on this? I would like to learn.
Math is hard. The numbers don't say there's a 95% chance he's a winner. They say something else entirely.
There are essentially two numbers to consider, the win rate and variance. Of course, JV hasn't actually supplied the variance, so even the basic results are a bit tenuous. UprightCreature posted some very basic numbers which say that getting DERB's results over that stretch for a break even player is maybe a one in a million event.
Now consider the fact that DERB is not alone in these achievements. We aren't talking about some guy that just got lucky.