I think Roberson is probably one of the more live dogs on this card, I favour Vettori to win but it isn't going to be the wash out the line indicates in my opinion, simply because Vettori seems to be missing that next gear so far in his career, which probably explains his lack of finishes.
I'd give Roberson a power and speed edge and he's probably the slightly better technical striker.
Vettori's path is clear, apply the pressure in boxing range, and grab takedowns and control where opportunity presents itself.
The issue with Vettori is he's hot headed, and I would expect even more so in this fight after Roberson's failed weight cut last time out. If he's not got his emotions under control, comes out fast and hard he could walk into something and get hurt early.
It Roberson can keep the distance and in the process stab at Vettori with kicks he could accumulate damage and potentially steal close rounds also. Vettori seems to be improving fight to fight and I think at his best he could very well be top 10, but until he can turn up the dial and really put a stamp on rounds he will continue to be in close fights.
I see Vettori as a less threatening, less dangerous, less pressuring Paulo Costa. A big, tough, bully who works best in close range.
In the larger cage I'd consider a small stab on Roberson, but in the small octagon I think there are enough things swinging in the direction of Vettori's strengths that he is the pick.
Pressure forward, take away space, cut off the cage and don't allow Roberson to rest or establish the mid range.
I feel the line could be closer, but that Vettori does enough to get the win, if we see a total shut out or better still a finish from Vettori here I would have to think he has turned a corner and is ready for a step up.