This is something I've recently been wondering about. You almost never see people use rear leg side kicks in mixed-martial arts. Side kicks are very rare in MMA anyway but when you do see side kicks in mixed martial arts, you almost always see them used from the front leg. Stephen Thompson uses them brilliantly in a variety of different ways with his bladed/sideways stance. He can use them similarly to a muay thai teep to keep his opponents from crowding him and keeping the fight at the long range distance he prefers to fight at. When his opponents do try to move in, he can intercept them with side kicks to the body to knock them off their feet like he did to Masvidal (or even his catch them on their heels like he did to Luque). When his opponent is hanging out at long range, he can even fire them to up to the head to land a significant strike as he did again to Masvidal or like how Ricky Bandejas knocked out James Gallagher. But you almost never see fighters use this technique with the back leg. I started martial arts from a ****o-ryu karate background and over two decades got pretty good at using that technique. It has a surprising amount of power to it as you're striking with the heel and opponents seem to underestimate the distance from which you can attack them with it. So why does nobody in MMA use this technique? I remember that Georges St-Pierre used them pretty effectively against Bisping both to do damage to the body and for distance control by keeping him backing up. However, normally, you only see them use this technique when they throw a round house kick that their opponent backs away from, at an angle where they can counterpunch, and they chain a side kick to failed kick to dissuade their opponent from exploiting their angle to counterpunch. Is it because it the technique has a long loading time and thus is pretty easily telegraphed? Since it moves up into a chamber position, most of the time, you don't know if it's going to be a front kick or side kick until the hips turn. Is it because they're afraid being jammed and their opponent's counter punching before they can fire it? Are they afraid of it getting it caught and it providing takedown opportunities? That doesn't seem to stop them from throwing other types of kicks. Are they worried about the kick missing entire and giving their opponent an angle to knock them out like Pettis did to Thompson? Or is it really just because not that many mma fighters start in the specific karate styles that emphasize them from a young enough age to really master them? What do you guys think?