The punch, called a "casting punch", is most commonly used in Sambo and most notabley used by Fedor Emelianenko. The punch is sort of a whipping motion that we've seen Fedor use numerous times. The problem with the strike is that it is the reason that Fedor has had so many hand injuries over the years. You're essentially hitting your opponent with the side of your hand.
Obviously, Fedor has used it with a lot of success and it is very useful in an MMA fight because it's purpose is to avoid strikes and get inside on your opponent which allows for clinching. Fedor is one of the least hit fighters of all-time, the "casting" technique keeps your head far away from your opponent's attempts to counter as you see in the picture above.
In the video below The Fight Nerd demonstrates this technique in-depth. So what's the verdict? Did Chael Sonnen use a technique that Fedor has mastered and put it to use against one of the best fighters walking the planet? If he did it would be a testament on the benefits of watching tape and trying to find any advantage you can in a fight. Which, judging by Sonnen's performance, I suspect he did.
(Originally Published on MMA Scraps, re-published here with permission)