I think forrest has a much better chance than stevenson. Forrest has decent enough stand up to atleast hang with rampage on the feet. IMO there is no way this fight will go to the ground because latley rampage hasn't showed any interest on going to the ground in any of his fights and forrest isin't strong enough to take rampage down. So this fight will stay standing and forrest has a slight chance to take it.
Stevenson however really has no chance IMO because he doesn't really have BJ beat in anything. They are both great bjj fighters but BJ is on a different level compared to any lightweight there. BJ has better standup, and he has great takedown defense. So he can keep the fight standing if he wants, or he can let it go to the ground and do what he does better then anybody
Fav Fighters- Penn, Jon Jones, Henderson