Kevin Holland is a black belt in BJJ. It’s the reason why he basically accepts being taken down cos he’s also skilled with his back on the mat. I mean it works against lesser fighters in the UFC but not against fringe top 15 guys and up. And once fighter enter top 10, he should at least have decent defensive wrestling... It’s modern MMA.
I've seen varying levels of black belts, and that's what's somewhat controversial in marital arts, is that there's no universal standard of a black belt. Although, Kevin is actually pretty decent at surviving the submissions thrown at him, so his BJJ does help him there. However, he rarely ever dominates on the ground, and I think his weakness of takedown defense, and threat on the ground has been exposed recently.
Fantastic fighter on the feet, decent at surviving on the ground, but being competitive on the ground? We haven't really seen that at all, except for his sort of freak knockout from the bottom.