I have read a few times on here that the front kick Royce uses is outlawed? I have never seen or heard of that before now. I know the gracies always taught it as a way to keep distance and close distance when attempting to clinch.
it is ILLEGAL to stomp on a downed opponent, but it is LEGAL to hit them with an axe kick (kick that has an arc to it). GSP did this to mayhem and its fair game cause the kick had an arch to it
Sorry for the confusion. I guess I was calling it a "stomp" because it is not really a kick, but more like a big step.
I think push kick is a better term. On it's effectiveness, I find it pretty effective at causing th opponent to sometimes drop his arms so you can clinch. More for a standing clinch than a double leg.
Also, it is a good set up for kick to the thigh with the opposite leg.
I think I've also heard it called a Stop Kick. Anyways... I don't it is used so much as a strike than as a setup for a clinch. Striking to joints is illegal last time I checked