Just look at his free fight against Pettis. A extremely talented orthodox tae kwon do black belt, traded with RDA most of RD1 and RDA did some severe damage to Pettis. I'm not saying Pettis is anything like McGregor, but the evidence is all there. RDA absolutely obliterated Cerrone who is also another high level striker. To top it all off, he can wrestle and clinch fk his opponent's as well , my opinion is McGregor better train his arse off if he firmly believe's he can take the 155lb gold. RDA has been thoroughly impressive as of recent and I believe this is going to be a very serious test for McGregor. One last thing, if the McGregoat KO's RDA, he is officially a UFC HOF'er in my and I'm sure many others book.