You rarely see them in MMA. Every now and then one pops up, but I can't think of the last time someone seriously attempted one in a title fight. Weidman vs Silva? Palhares had some good ones, but he never made it to title contention. Imanari back in the day. Is it even worth it? Might just be a better use of your time to work your wrestling and striking rather then trying to develop some crazy leg lock game that rarely gets pulled off, and you are rarely in the right position. I remember when everyone was hyping Danahers system, guys like GSP and Rory never successfully used them and probably should have just spent their time with the essentials . It works in pure grappling situations, but I rarely see it work in MMA. Ryan Hall over Old BJ hardly counts.