An often forgotton technique in MMA, the Anaconda Choke is a very good defence technique against shoot, you'll finds in training that only more experience grapplers will be able to defend against this choke since most MMA fighters mainly concentrate on avoiding the guillotine.
http://www.lockflow.com/article_view.php?id=2287
http://www.lockflow.com/article_view.php?id=2287