That makes Bonnar a +850 underdog, making this one of the more lopsided main event fights in UFC history. It's even more lopsided than the opening line for Jon Jones and Vitor Belfort next week at UFC 152, which saw Jones open as a -925 favorite for the bout.
Silva, the long-reigning UFC Middleweight Champion, jumps up to 205 lbs. for the third time in his UFC career, jumping in to try to save the event after it lost both Jose Aldo and Rampage Jackson earlier this week.
Penick's Analysis: The only reason this number is surprising is because it's not larger. Bonnar will rightfully be considered one of the biggest underdogs in a main event fight, because this is really just a glorified squash match for the greatest fighter in UFC history to date. And that's fine. Bonnar won't have any wrong ideas about his spot in this fight. It's a big opportunity for him to fight Silva, but no one at all expects him to actually win this fight. That's not what he'll be in Brazil for. He'll attempt to win, of course, and he wouldn't take the fight if he didn't think he could do something against the Champ, but he's essentially fodder for Silva's highlight reel in this one.