it wasnt the lack of bjj, that cost him this fight, it was the lack of a gameplan, well unless you call it a game plan to not jab and dont throw punches in general. He was looking for the one punch k.o, but he never got that opportunity. In the first round junior had several opportunities to jummp on cain after cain failed with a takedown, instead he chose to walk or run away. Awful game plan.
Cain on the other hand knew exactly what he had to do, he had a ganeplan from the get go and followed it. Greta performance from him.
JDS' only game plan was to try and land a quick overhand punch again because in reality that's all he's got on Cain and he knew it. JDS most definitely does not posses all the tools required to reign at the top of the HW division, that much is abundantly clear.
Cain even punished JDS at his one and only game. Cain is by far a much superior fighter.