...it is his black belt chin. He is amazing fighter overall, but he wouldn't be anywhere close to where he is right now if he had an average chin. It would have been cracked by now. He got tagged HARD by Brimage, Brandao, Siver and Mendes. By being able to absorb power punches he could keep pressing forward and employ his boxing and body kicks to break his opponents. If he didn't have this legendary chin, his run would have stopped somewhere around Brimage Brandao fights. Granite chin may not be enough to get past RDA though as I believe RDA will try to break Conor by body shots and then take the fight to the ground. Heart says Conor by knee KO in first when RDA shoots for takedown, but more likely it will be RDA by guillotine on exhausted McGregor somewhere in 4th round.