Danaher says:

Leg locks won’t work in MMA: A very commonly stated opinion is that leg locks won’t work in MMA. When the squad first began using leg locks in grappling competition, critics immediately claimed that they wouldn’t work against higher level opponents. Then when the squad started beating higher level opponents in submission only tournaments the same critics claimed that they wouldn’t work in a points tournament of the highest level such as ADCC. Then when the squad (and others) beat numerous opponents with leg locks in ADCC the critics retorted that they may work in grappling but you couldn’t use them in MMA because you would get pulverized by strikes if you so much as attempted them. I always laughed and shrugged my shoulders at this argument – the same way I did when the early critics said leg locks wouldn’t even work in grappling. There is nothing special or unique about leg locks. They are like any other martial arts technique – IF THEY ARE UTILIZED WELL AND AT THE APPROPRIATE TIME – THEY WILL WORK WELL. IF NOT, THEY WON’T. Every move has its good point points and bad points – their success or failure is not based on the move itself but rather upon our ability to exploit its good points while avoiding the bad points. I have seen grapplers who used triangles, arm bars, Guillotines, lose control of them and get pounded into defeat – yet no one claims triangles, arm bars or guillotines should never be used in MMA. Moreover, there is plenty of historical evidence of leg locks being used successfully in mma for a long time. Understand that the success or failure of your moves is tied much more to the quality of your applications of the move than to the moves themselves. Almost all of the major traditional moves of Jiu jitsu are capable of winning a fight if your use of it is good. Focus on the quality of your application to make your moves work rather than what people try tell you will work and you will find your own creative ways to victory as Neiman Gracie did last night with this beautifully applied hybrid inside heel hook/knee bar leg lock over one of the greatest welterweights in history