He does have more than 50% chance of winning the fight, I couldn't however bet for him since Chimaev can handle a fight. The only challenging fight we have seen so far from him was with Burns.
If you give Usman more than 50% chance and the payout rate is over x3, then you have yourself a great value bet right there.
I would see it as a 50/50 fight if Usman had more time to go through a full camp but given the short notice, I see him as an underdog.
I still can't imagine Chimaev just running over Usman in a 1st or 2nd round, like he did to many opponents in the past. He probably will take a win by decision.
So I guess the original plan for Chim was to fight Costa then fight somebody in 185's top 5 then a title fight.
Haven't they announced that the winner of Chimaev Vs Usman will get a shot against Strickland? I've heard that somewhere but don't know if it was only a rumour or confirmed information.