"Kickboxing" is a general, catchall term used to describe a number of full contact fighting styles and combat sports. To the casual observer, these styles appear to be similiar to Western boxing, only with the inclusion of kicks. What distinguishes the kickboxing styles from the non-kickboxing, full contact martial arts competitions - such as Kyokushin style "Knockdown" Karate and WTF ("Olympic") Taekwondo - is the allowance of hand strikes (ie punching) to the head; the latter two types of competition do allow for knockouts, but only with kicks; full power punches are limited to the body. Kickboxers wear boxing gloves and are not as limited in their choice of target areas. (Note: "Full contact" is used in this context to refer the level of intended contact strikes are thrown. Kicks and punches are thrown with full power and are not pulled or stopped before contact is made. The vast majority of martial arts do not practice full contact sparring.)
Historically, the term "kickboxing" came into common usage in Japan during the 1970's. Japanese fight promoters of the time were experimenting with different sets of rules to accomodate the vastly different styles of fighting that were then achieving international popularity. The only thing common to all the rulesets of the different promotions were boxing gloves and kicking, thus "kickboxing" became the logical term to apply to all of the new hybrid rules competitions. Contrary to popular belief, it was only after the term "kickboxing" was cemented into the lexicon of the Japanese fighting world was it applied to muay Thai and North American Full Contact Karate.
The standard set of rules that came to be settled upon resembled something between muay Thai and the various North American and European styles. Like Thai boxing, the entire body, except for the groin, was a legal target area. Like Thai boxing, knees and shins were legal weapons. Unlike muay Thai, elbows and throws from the clinch were not allowed. Further more like North American rules, clinches were generally broken up within a few seconds. The general rules would eventually be formalized into the ISKA's freestyle and Oriental rules divisions but these would soon be eclipsed by the advent of the K-1 fighting circuit.
The following are quick summaries of the major kickboxing styles. The K-1 is not strictly a fighting style so much as a set of rules, but because its influence is such that almost all major fights now take place under its sanction, it deserves to be mentioned as the primary form of kickboxing competition.
The K-1 fighting circuit is the currently the world's largest and most prestigious kickboxing circuit.
Bouts are five rounds by three minutes per round. All kicks, knees and punches are allowed. The entire body can be targeted, except for the groin. Elbow strikes and headbutts are prohibited, as are throws, takedowns, and submission techniques. A fighter that catches the kick of his opponent is allowed one attack while he is holding the leg. Kneeing is allowed in the clinch and clinches are only broken up when no action is taking place.
Fighters fight several times a year at K-1 sanctioned events for the right to enter the annual K-1 World Grand Prix, a two part, sixteen man tournament. The first round of elimination takes place two months before the second one-night, eight man tournament. The eight man tournament has an abbreviated round schedule of three rounds by three minutes.
When the K-1 first came into existence during the early 1990's, it was intended as a forum for fighters of all styles to determine the superiority of both individual fighters and fighting styles. The fighters that enjoyed the most early success came from muay Thai backgrounds with the notable exception of a few Kyokushin stylists. The K-1 circuit is now so popular, with the largest fight purses outside of professional boxing, that top fighters train for the K-1 to the exclusion of other fighting circuits. Young up and coming kickboxers no longer start in different backgrounds and "cross over" to the K-1 but train for the K-1 and only see various world titles and championships as a stepping stone to break into the major league of fighting circuits. Top K-1 fighters are generally regarded as the best all around strikers in the world.
Criticisms of the K-1 include the lack of weight classes and the neutering of clinch fighting. A more recent criticism leveled at the organization by fans and fighters alike is the Japanese infatuation with David and Goliath style matchups.
Full Contact Karate
Muay Thai, also known as Thai boxing, is the undoubtedly the single most brutal combat sport in the world, period. Fighters who have competed in both muay Thai and UFC style Mixed Martial Arts fighting will tell you that the level of punishment exchanged in MMA fighting rarely approaches that of even an average intensity Thai bout. (Personal note: Having fought/trained for both types of competition, I can tell you that muay Thai is an order of magnitude rougher on the body.)
Thai boxing matches are five rounds by three minutes long. The entire body, with the exception of the groin, is a legal target area. The entire body is a legal weapon, with the exception of headbutts, although it is not unknown for smaller stadiums in Thailand to look the other way when an occasional butt is thrown. Clinches are not broken up and are allowed to go to a natural conclusion. Throws from the clinch are allowed and although they are not a scoring criteria, throws can knock the wind out of a fighter as well as psychologically demoralize him by forcing him to pick himself off of the ring floor. Clinch fighting and neck wrestling are some of the trademarks of the Thai fighting style and this is where the very dangerous business of elbow and knee exchanges takes place.
International rules muay Thai civilizes the sport a bit by limiting the clinch action and often prohibiting elbows, depending on the jurisdiction where the match is taking place. Some sanctioning bodies force elbow pads to be worn in elbows-legal matches, which is counter productive because leather on skin is actually more likely to cause cuts and tearing of the skin than a bare elbow.
Thai style fighting's greatest contribution to the world of martial arts is what is commonly referred to as the "Thai kick", a heavy, whipping rear-leg roundhouse delivered with the shin against the outer thigh of the opponent. This kick is particularly debilitating because it compromises the opponent's mobility. Even a single kick to an unconditioned opponent who is unaccustomed to taking this sort of punishment is enough to induce a charlie horse and a severe limp. Many TKOs in this sport come about because a fighter falls to a kick and is no longer able to stand up, much less continue to fight.
Contrary to popular belief, there is no such thing as a Thai national champion. The most prestigious titles to hold in Thailand are either the Lumpinee stadium or Rajdamnern stadium championships.
Critics of muay Thai point out the relative crudeness of Thai techniques. There are styles which teach superior kicking and punching, but generally not both in the same art. Another major criticism is the brutal nature of the sport - it is often the best conditioned fighter who wins, not necessary the most technical one.
Full Contact Karate is an outgrowth or evolution of the old "point fighting" karate competitions. Point fighting was the competitive version of the kumite sparring done in traditional Karate dojos. Most Karate ryus practiced non-contact sparring, where the idea is to kick and punch with full force but to pull the blow at the last second and leaving an inch between a kick or punch and the intended target. When this became a competitive so called "sport" in North America, a few competitors realized that because no contact was being made, they could trade off power for speed. Many competitions quickly devolved into a game of glorified tag with martial overtones.
A number of competitors eventually grew disgusted with point fighting and decided they needed a form of competition where they could actually hit the other guy and not be disqualified for using excessive force. Thus Full Contact Karate was born. The early days of FC were quite a circus with no standardization of equipment, length of matches, or attire. The sport eventually settled on two minute rounds with a variable number of rounds. Equipment and attire included boxing gloves, groin guard, shins guards and instep guards as well as long pants. The only permitted strikes were punches and kicks, targetted above the waist. Strikes such as elbows and knees were prohibited. The comedy value of these early matches was further increased because many fighters were lead to believe by their martial arts instructors that their fighting techniques were so devastating that matches would be over within a few seconds. Most fighters were woefully unprepared for the reality of the ring. Often, fights ended with a fighter giving up, not due to injury or knockout, but because they couldn't continue due to lack of cardiovascular conditioning!
What quickly became apparent was that fighters with knowledge of boxing training methodology were at a huge advantage. Boxers knew how to train for in-ring endurance, but more importantly they knew how to train to actually hit and be hit, something that karateka of the time lacked. Full Contact fighters quickly learned to train like boxers and eventually, thats what Full Contact Karate became. Many fighters just boxed in the ring and didn't kick at all. After all, a single kick takes more energy that several punches and since all targets were above the waist, the more clever fighters soon figured out that kicking was a waste of energy. To combat Full Contact Karate from turning into boxing, the sanctioning body instituted a minimum eight kick per round rule, forcing fighters to throw up kicks, something no other kickboxing style has had to do.
This fighting style saw its heyday in the 1970's and 1980's when Full Contact Karate fighters were considered the toughest guys on the block. With the growing awareness of muay Thai and Japanese style kickboxing, FC fighters lost a lot of that mystique. Interest waned as many top fighters defected to the "leg kick" styles of kickboxing and muay Thai. Today, this style of fighting is on its deathbed. More than half of the ISKA's championship titles stand vacant and very few, if any, young potential fighters train to fight in this style.
The following two styles are a bit more obscure, for different reasons, but both fit under the the umbrella definition of what most would call kickboxing.
San Shou - Also known as Sanda or Chinese Kickboxing, the sport of San Shou is a relatively new one. What distinquishes this style from the other kickboxing arts is that it the use of takedowns and throws are encouraged and scored. Matches are five rounds by three minutes, with throws being the major factor in awarding rounds to a fighter in the case that the fight goes to a decision. There are a few dynamic fighters but this style is suffering from a lack of interest from top fighters.
Critics of this style are quick to point out that the cross-trained striker/grapplers who enjoy great success in the Mixed Martial Arts competitions such as the UFC, Japan's Pride Fighting Championships and particularly the hybrid fighters from the Pancrase and Shooto styles could easily dominate a San Shou ring but have no interest because of the loss in pay and prestige. Some also point out that as a cohesive fighting philosophy, San Shou doesn't make too much sense. As a kickboxer, you want to remain standing in a fight, not go to the ground.
Savate - A French (!) kickboxing style also known as Boxe Francaise. The origins are French, but are a bit murky because different people make different claims. Evidently, 18th and 19th century French street fights were kicking oriented, but some claim otherwise. Fighters wear special kicking shoes and kick with the point, the favorite target of which seems to be the inner thigh. The gloves seem outlandishly big to my eyes. Okay, honestly, I don't know much about this style or its rules. I have only seen a few matches and don't know what to make of it. I only included it here for completeness. If someone knows anything about this style, please help me fill this section out.
Comparing the styles - This is a topic that can encite a religious flamewar between adherents of different styles, but here goes my attempt at a neutral quick and dirty analyses.
As was mentioned in the section on Full Contact Karate, interest has long since waned on the Full Contact kickboxing style. Fighters coming from this style generally had the best hand techniques outside of professional boxing but compared with the other styles had notably weaker kicking. With the exception of a few fighters, kicks were rarely thrown with knockout power and were more of an annoyance to both the kicker and his opponent. It was the rare fighter who could get kicking to pay off in Full Contact.
Allowing the legs to be targeted, particularly the outer thigh, completely changes the manner in which kickboxing matches are fought. Mobility simultaneously becomes more important yet harder to maintain due to the threat of someone taking out your legs. A limping opponent who is visibly limited in his mobility and power base is an extremely vulnerable fighter. Furthermore, as counterintuitive as it may seem, the opening up of the legs as a target area for kicks increases the probability of knockouts via a high kick. The natural reaction of a tired fighter who is recieving a beating to his legs is to drop his hands to defend them. Most head kick KOs come when the kicker switches targets from low to high and the victim is still defending the low kick. It's due to this phenomenon that the knockout rate in the K-1s are above 90%. A minimum kick rule has never had to be implemented in a kickboxing match that allow the legs to be kicked because it is a very effective avenue of attack and one of the fighters in the match will invariably attempt to pick apart his opponent's legs.
Oddly enough, after their initial splash, the style and techniques of the Thai boxer have made more of an impact on the international kickboxing scene more than the fighters themselves. Muay Thai fighters in Thailand begin to fight professionally in their teens and most have fought over one hundred matches by the time they are ready to retire in their early twenties. Due to the amount of punishment that a Thai boxer endures over his career, very few reach what is considered in the West to be prime fighting age (late twenties to early thirties). In addition, the top international kickboxers are all extremely well conditioned, nullifying the legendary conditioning advantage of the Thais. This is where the weaknesses of the Thai style becomes noticable - international fighters come from varied backgrounds with a breadth of knowledge that the strict Thai boxer does not possess. An individual kickboxer might bring superior boxing skills or kicking to the table and drives technical innovation throughout the sport. The only area where the orthodox Thai boxers still exhibit clear dominance is fighting in the clinch.