Mixed martial arts is one of the most unpredictable sports on the planet.
So many different things can happen in a fight, and so many factors are impossible to determine until a fight actually happens.
For example, Rashad Evans is fighting Tito Ortiz at UFC 133. That whole fight is pretty much riding on whether or not Tito can take Rashad down.
The two men have fought once before and Ortiz was able to take Evans down, but Rashad has improved since then and Tito has had multiple surgeries. So, will Ortiz still be able to get the takedown? We really won't know until the fight happens, and that will likely be the deciding factor.
Even when the outcome of a fight seems blatantly obvious, we can never be certain who is going to win.
Frustrating as it may be to you gamblers out there, the unpredictability of MMA is one of the most exciting aspects of the sport, and it's always a scintillating moment when a fighter who isn't supposed to have a chance in hell of winning, pulls off the victory.
Let's take a look at the 25 greatest upsets in UFC history.