Lyoto Machida vs. Vitor Belfort was seen as a Sad Old Man fight by the majority of fans from the moment that it was made. A simple trotting out of old boys who still have name value among Brazilians. Nothing about the finish changed that, of course, but it had one hell of an ending. In a call-back to Belfort’s most famous loss, the former Phenom folded down into himself after a Lyoto Machida front snap kick had peeked up through the blind angle and exploded on the point of his chin.

Belfort’s knockout loss to Anderson Silva in February of 2011 was the first from a front snap kick to the jaw in the UFC. Lyoto Machida’s against Rich Franklin in 2003 was one of the first in high-level MMA competition, and he followed Silva’s famous knockout with a jumping front kick knockout of Randy Couture in April of 2011. The front snap kick is becoming considerably more common—in fact we examined the great Takeru’s lead leg kicking game a few days ago—and snap kicking to the body has become a real game changer in MMA. Just the other week Siyar Bahadurzada sent his man to the mat with a front kick to the solar plexus. So why would the front snap kick underneath the jaw—a beautiful, devastating technique—still be such a rarity?

When a fighter targets the head with front kicks he gives himself a difficult task. A front snap kick, hinging at the knee and rising up underneath the opponent, is not a very versatile weapon in its range. The front snap kick is one of two main strikes which exploit the blind angle beneath an opponent’s vision. One of the reasons that the front snap kick became so popular in competition karate back in the 1960s and 1970s is that the lead foot can be placed underneath the opponent’s field of vision and then brought up to score a point. Consider the other main strike in combat sports which enters through this blind angle: the uppercut. The uppercut is performed with the legs and shoulders—the elbow isn’t one of the key moving parts in the strike, it is an adjuster for space and range. Want to uppercut someone with their head right next to yours like Jack Johnson or Gennady Golovkin? You bend your arm up tight and turn your hips all the way through so that your uppercut is jamming up next to your own head.

Demonstrated here by Josh Barnett.

Want to throw a long, Alexander-Gustafsson-flirting-with-danger style of uppercut? Take some of the bend out of that arm and arc the blow on an incline. The closer you are, the more vertical the path of the punch. The further away, the more of a forward arc it takes.

The problem with adjusting the front snap kick is the knee—sometimes called the elbow of the leg, but not by any respected medical professionals. In the uppercut the elbow takes its position and then simply braces for impact, the knee is a hinging point in the front snap kick. The knee goes through its full range of motion to provide the snap. Because the full range of motion in the knee is what makes the kick, it is very difficult to shorten the front snap kick. You can lengthen it to a degree with how much you turn or don’t turn your hips, and how much you throw your weight forward, but you can’t shorten it. For as useful as the front snap kick is, it is not a forgiving kick to apply—the fighter must have his distancing down or he is going to end up muffling himself or missing completely.

The relatively small window of effective range is the main reason you so rarely see knockouts from front snap kicks to the face in MMA and kickboxing. Belfort—perhaps the only person in MMA to have suffered two, identical losses by eating the kick—suffered them partly due to his habit of getting into a staring contest with his opponent, just on the end of their kicking range. During the UFC 224 broadcast, Belfort’s corner was shown for an extended period of time, repeating over and over that Belfort should move in off blocked kicks. Instead Belfort simply stood there, waiting to get comfortable and never capitalizing on Machida being on one leg.

You can just as readily watch fighters overuse the front snap kick and come out looking very foolish though. The welterweight Dong Hyun Kim was famous for finding something "unorthodox" and then doing little else, running the tactic into the ground. At one time it was spinning backfists and elbows, but against Sean Pierson it was the crane kick or bicycle kick. Just as Machida did against Randy Couture, Kim would pump one knee and leap into a front kick with the other leg. It worked once in about forty times, through Pierson’s own fault rather than any deception or guile on the part of Kim.

While the front snap kick to the jaw works well against static opponents, it works even better against predictably plodding opponents. When the fighter walks in on a straight line at a set pace, time and time again, the pursued fighters is simply playing Space Invaders. The path of his opponent’s head is the same, so he just needs to time setting his feet and kicking up underneath. In the same way the great Willie Pep would lead with a long right uppercut—something which is conventionally a terrible idea. But let’s not get distracted by Pep, though, the most famous example of walking a plodding fighter onto the front kick is Travis Browne vs. Alistair Overeem. Overeem seemed to be in complete control of the fight, but kept walking forward in his hunched over stance, chin projected and a beautiful opening from underneath. Browne showed him the kick at least four times en route to starching the Dutch giant.

A more recent example of the exact same principle happened just last week. Batraz Agnaev was the ACB light heavyweight champion and though he had just four fights under his belt, he was a man to watch. We even examined him in an extended Prospect Watch. Agnaev is hard to take down, harder to keep down, hits with monstrous power, and has already got a better grasp of ring positioning than most fighters ever learn. If he has one problem it is that he just doesn’t throw enough strikes. Against Thiago Silva, Agnaev walked Silva to the fence constantly but threw punches very sparingly before finally uncorking the right hand ten minutes into the fight. Dovletdzhan Yagshimuradov found himself on the fence early and often, but soon realized that he wasn’t actually being hit that much. Two minutes into the second round, Yagshimuradov moved around the cage and as Agnaev followed he tried his best to make the champ bite through his gumshield on a beautiful snap kick to the jaw. Agnaev swung clumsily after he was stung, and Yagshimuradov got the takedown, advancing to back position and finishing the ACB champ with a choke.

While Randy Couture fell victim to a nice feint, the front snap kicks against Vitor Belfort and Alistair Overeem highlight one very nice advantage of the technique. Even if the knockouts aren’t common, the front snap kick punishes fighters who rely on propping up their forearms either side of their body like a pair of pillars expecting them to absorb all the round kicks that their opponents throw. Alistair Overeem’s K-1 run demonstrated how much can be accomplished against more orthodox kickboxers simply by shelling up and getting in off blocked round kicks. Belfort and Overeem both took a simplistic approach to dealing with kicks, putting up walls either side of their body but neglected that space straight up the center line.