This page is act as a resource for anyone wishing to better understand the subject of kata bunkai. Please feel free to email me if you have any questions about our approach to kata and bunkai, or even bunkai for the kata in your own system (assuming of course that your kata share some common themes with our own). I will attempt to answer your questions, as best I am able. I shall start off the discussion myself, to give a general outline to the subject and our approach to it. This page is organised as a blog, so please start with the bottom post and work up, in order to make best sense of the information.
Recently in our dojo we've been discussing and looking at yoi, I thought I'd share some of those thoughts...
Most people who have an interest in bunkai probably already think of yoi in terms of technique, but its worth looking for a moment at the usual karate-do explanation. Yoi means 'ready' to most karateka. How is standing with your feet parallel and your hands (more or less) by your sides being 'ready'? Quite simply, it isn't. If your 'enemy' is in sight then you don't want to stand with your feet parallel, you stand with one foot forward (or one back - however you want to think about it). That way you draw your groin away from danger, and both manoeuvrability and stability are improved. If the 'enemy' is close enough to launch an attack then you want your hands up in some sort of guard. Standing with feet parallel and arms by your sides is ready for only one thing: a good kicking!
So if you're not being 'ready', what are you doing? In my opinion you should either think of it as a technique or abandon it as irrelevant ritual. For me, it very definitely has martial value. To understand how Yoi can be used we must first understand the movements involved and how they generate power. I make no apologies for using anatomical terminology in describing these movements. It is the only way to fully and unambiguously describe human movement. It also provides a useful reality check for your bunkai - if a suggested bunkai doesn't use any of the described movements then it can't really be considered bunkai of the kata movement. I have however linked to some other sites which demonstrate the anatomical terminology used.
Like many karate movements Yoi has two phases. In phase 1 each arm is adducted with the shoulder slightly flexed, ie. the hands are brought across the body low down to cross the midline. At the same time there is a slight degree of elbow flexion (bending the arm at the elbow) and forearm supination (some styles place much more emphasis on the elbow flexion and supination). At the end of phase 1 the arms are crossed at the wrists, with the right arm uppermost. In phase 2 the actions are reversed: the arms are abducted (the opposite of adduction) whilst maintaining the shoulder flexion, simultaneously the elbow extends (ie. the arm straightens) and the forearm pronates. In other words, the arms uncross and separate.
In both phases of Yoi the movements are mutually supportive, ie. in phase 1 the arm adduction, elbow flexion and forearm supination are each made stronger by virtue of being combined together. So the whole movement is all the more powerful. The same goes for phase 2. But the movement can be more powerful. Yoi uses both arms not just one. If each arm movement is applied to the same part of the opponent's body (or at least closely connected parts) at the same time then the power is at least doubled. So the power generation principle embodied in Yoi could be described as 'cross and uncross your arms to generate power (low)'. I add the term 'low' to differentiate between Yoi and other kata movements in which the arms are held higher but still cross and uncross.
We can also describe Yoi in terms of a tactical principle - that is to 'pass from one hand to the other'. The following applications (described below and shown in the video) will demonstrate how the Yoi movement can be used to generate power in order to apply this tactical principle.
Technique 1 - uppermost hand removes a same-side wrist grab on the leading leg side
This is the first application of Yoi that students learn in our dojo (and is described in more detail on the Videos page). As the forearms cross the right (uppermost) hand pushes the attacker's wrist away from the grabbed (left) hand and seizes it in one motion. In Okinawan Karate this is often known as the 'old man's wrist release' because it takes very little strength to make it work. The footwork (sliding forwards at 45 degrees) supports the arm movements, helping to a) unbalance the attacker and b) blindside them to place the defender in a more advantageous position. From this point it is easy to follow up with a variety of strikes whilst controlling the attacker's wrist.
Technique 2 - uppermost hand removes a same-side wrist grab on the trailing leg side
This is similar to the first technique, but stepping out to the front left is fraught with difficulty. Instead the defender moves to his rear left. This slightly changes the way the attacker's wrist is captured. In technique 1 a rapid grab is critical, with the attacker's forearm oriented so that the thumb is uppermost. In this technique the attacker is allowed to maintain their grip during the initial footwork. This leads the attacker and rotates their forearm so that the palm is uppermost, allowing the defender to grab and twist the wrist so that pressure is applied to a vital point overlying the radius bone. The mechanics of the technique work anyway, but can be augmented by pressure on the vital point. As before, this unbalances and blindsides the attacker,making it easy to apply follow-up strikes.
Technique 3 - lower hand removes a same-side wrist grab
Here it really doesn't matter which foot is forward to start with. Instead of the uppermost hand stripping away the attacker's grip, the lower hand captures the attacker's hand from below. The movements of phase 2 apply a lock to the attacker's wrist - the left (lower) hand applies the lock and the right (uppermost) supports the work done by the left. This will throw the attacker, but in doing so he is released from the lock. The defender can however prevent the release by applying the Yoi principle again. The right hand grabs the back of the attacker's hand and continues to twist (Yoi phase 1) so that the left hand can again grab it from underneath and continue the twist (phase). The defender's knee is used to stop the attacker rolling out of the lock once he's on the ground. This second Yoi is not easy to see on the video but the end point of the lock is clear.
This second Yoi highlights an important point. All 3 applications so far can be considered 'entry techniques' in that they show us how to use the Yoi principle deal with the initial attack. They are our first response to the physical assault. However, Yoi could equally be used as a) an intermediate technique, not necessarily a fight ender in itself but something that moves us in that direction, or b) the finishing or exit techniques, in that it allows us to finish the confrontation and safely disengage. The second Yoi here could be considered either intermediary or finishing/exit. It can be used to pin the attacker so they cannot escape our strikes, or simply to damage the arm and escape.
Technique 4 - lower hand removes a cross-arm wrist grab
As with technique 3, its the lower hand that removes the grip. And it doesn't matter which foot is forward. Phase 1 sets up the wrist grab, phase 2 (especially the pronation) provides the power to disengage the attacker's grab. This technique feels essentially the same (from the defender's point of view) as technique 3, although the footwork is different. Probably the most appropriate follow-up is to use gedan-barai (downward sweep) to bar the captured arm.
Technique 5 - Capture one arm and pass it to the other
This is essentially the same as technique 1, but it works at closer range, ie. a clinch. Having managed to capture the attacker's right arm with your left hand, it is quickly passed to the right hand. By grabbing the upper arm rather than the wrist the defender can slip round to the attacker's blind-side whilst simultaneously unbalancing them. From here it is easy to strike to the back but some sort of control or takedown should be quickly applied to prevent the attacker reorientating themselves.
A note on footwork
In itself yoi doesn't give us any clues regarding footwork or body movement. In application the footwork should be chosen so that it achieves 2 goals: a) it supports the mechanics of the arm movements and b) it moves the defender away from the attacker's free hand and/or to a position blindsiding the attacker. The exact footwork can be quite different in different applications. The above techniques demonstrate this, achieving both goals by a variety of different footwork. The lesson here is that we shouldn't be slaves to the shape of the kata, but should use its principles freely to achieve the required outcome.
The above applications shouldn't be seen as an exhaustive list, just a starting point for further exploration. For example, techniques 1 - 4 all assume the attacker has grabbed the wrist. But in technique 5 the defender grabs the attacker's wrist to initiate the technique. There are plenty of other instances where this idea can be used (eg. using the arm circling at the start of Kusanku / Kanku Dai to feed the attacker's arm in to your grab). You don't even necessarily need to grab the wrist in order to pass it to your other hand, it could be achieved using muchimi (sticking) to feed the limb from one arm to the other.
Steve Derbyshire, of Leeds Shinseido, wrote (26/02/11):
Generally speaking in traditional martial arts you are required to perform a kata for each grading, so by the time you grade to Shodan you could easily know 10 or more kata patterns. Having said that how many kata in your opinion need to be studied from a bunkai perspective to be confident that all the bases are covered.
In truth I don't think any number of kata will truly cover all bases. After all, kata won't teach you everything about Karate by itself. There's always the chance that you'll come across useful, consistent techniques that rely on mechanical or tactical principles that aren't expressed in your kata. That would still be true even if you made up extra kata to incorporate all those 'new' principles. So you'll never cover all bases.
But you should be able to cover most situations and techniques, otherwise what's the point of kata? So how many is enough to achieve this goal? To understand that, one place to start is the past. There are plenty of anecdotes suggesting that prior to the development of Karate-do in the early 20th century most practitioners knew only a handful, say 3 or 4, kata. Only teachers tended to know more. Of the big names of the early 20th century we know that Gichin Funakoshi trained in only the 3 kata of the Naihanchi series for his first 10 years in training; Choki Motobu was thought to only know Naihanchi and Passai, but this appears to have been rumour put about to discredit him – it is true though that he placed much emphasis on Naihanchi in both his teaching and his own training; Kenwa Mabuni on the other hand made a point of learning many different kata from different Okinawan teachers. The overall impression though, is that students would learn fewer kata and – by modern standards - study each one for a very long time.
There is one historical tradition that I can talk about with some degree of certainty. In the Matsumura system there are between 9 and 13 kata, depending on who you ask. The core 9 are: Naihanchi (1 & 2), Passai (Sho & Dai), Rohai, Chinto, Useishi, Kusanku and Hakutsuru. Various sources might also include any or all of the following: Pinan 1 & 2, Naihanchi 3 and Seisan. Just looking at the core 9 kata, these are certainly not optimized, in that some moves are repeated across different kata. I think the reason for this is that they were not all created by the same person. Rather, some of them were produced in isolation by different teachers. Later they were then collated, presumably by Sokon Matsumura, into 1 set of kata. A similar process appears to have happened in other Okinawan systems. If someone today took it upon themselves to winnow these kata down, removing duplicate movements or principles across the different kata, they could probably reduce the 9 kata down to 6 or 7 (of similar length).
In the Leeds Shinseido dojo we teach several modern kata before the student is introduced to the above-mentioned classical kata. These are Shinzen, Sanchin, Pinan Daikou, Keri-waza and Shinsei. Shinzen and Sanchin are both very short and do not have associated bunkai in the way the other kata do (we use Shinzen to teach the use of body language and Sanchin some core mechanical principles – these principles are so widespread that they can't be associated with particular bunkai in the usual manner). Keri-waza is simply a kicking exercise, following the floor pattern of the Pinan kata. It has bunkai but they are by definition relatively limited so it lacks the depth and profundity of the classical kata. Pinan Daikou & Shinsei on the other hand are both quite long and are used specifically to teach certain principles (in the case of Pinan Daikou) and techniques (in the case of Shinsei). The majority of techniques learnt as kyu grades are drawn from or inspired by these 2 kata.
The point of providing all this detail is to demonstrate this: each kata is there for a specific reason, to teach its own specific lessons. Its not just 'thats how its always been done'.
So we have the 5 modern kata for the kyu grade syllabus and 10 classical kata for the dan grade syllabus. No doubt I could whittle down the classical kata but I don't feel that I have the right to do that. Rather I reserve them for dan grade students, who I feel have the long-term commitment to be given the kata as they are and make up their own minds as their relative value.
This I feel is an upper limit, for both kyu grades and dan grades. Any more and I feel it would become very difficult to study the kata in any depth and they would thus become a pointless exercise. I'm sure you could get away with less. Indeed, much of my effort as a teacher over the past several years has been to attempt to do just that, which is why we currently have the 5 kyu grade kata (also note that it typically takes rather longer to reach dan grade in our system than it does in most, which means even longer spent on each of the kata).
So back to your original question. I think about 5 before dan grade is much more sensible than the 10 you mentioned. You could arguably do it with less. But rather than worry about the exact number, I think its more important to understand what each kata is teaching. If its not teaching anything new, then why learn it?
Does it work using realistic attacks or stylised karate attacks? Bunkai is about self-defence, so your likely to be dealing with the sort of attacks initiated by thugs, not by trained martial artists. If the bunkai requires that the attacker uses say, a formal lunge punch or a high side kick for it to work, then you've got to treat it with suspicion. Even worse, if the attacker throws their technique and then has to stand there stationary while you 'work your mojo' then it really is straying into the realms of fantasy. Of course, good self-defence techniques should be able to deal with stylised karate attacks but, more importantly, they should also be able to deal with more realistic attacks such as grabs, holds, wild punches, low kicks and so on. Good bunkai will reflect this.
Don't get too wrapped up in sequences. About 10 or 15 years we would get very excited about bunkai where several moves from the kata could fit together in the correct sequence. This was seen as a sign! If it fitted so well it must be what the author of the kata intended. But if we think of the kata movements as principles then it really doesn't matter whether we fit our techniques to the sequence of the kata or not. The principles should be used as required, like tools in a toolbox. You pick up and use whichever tool is appropriate, changing tools freely according to the needs of the situation. If you had to use the tools in a specific order it would be very limiting!
Some people string sequences together in an even more limiting way, with the attacker blocking the defender's counterstrike and so on and so on. If this were really how bunkai worked the permutations would be endless. And practising one permutation would do little, if anything, to prepare you for all the other possible permutations. Good bunkai, by contrast, should stifle the attacker's ability to throw a second technique. The key to achieving this, usually, is to disrupt the attacker's balance. If their balance is broken then its difficult for them to throw another strike (or alternatively to stand there in a pretty stance while you show off your cool bunkai).
Make the kata work for you, not the other way round. Again, this really hinges on the obsession people have with matching the sequence of the kata. I've seen plenty of bunkai that starts off well, but after their first move the defender then strives to make their follow-up techniques match the sequence of the kata. Often there are simpler and more effective things they might do instead. But they have fallen into the trap of thinking they have to do the next move in the kata. They are working to fit the kata. Never forget, the kata is a training tool, nothing more, a resource for you to dip into as required. Make it work for you, not vice-versa!
So with that in mind, have a look at the following clip. This is just one of many hundreds (if not thousands) of similar clips on the internet. Is this realistic bunkai, using the principles of the kata to deal with realistic attacks; or is it a desperate attempt to make reality fit the kata, reliant on wholly compliant attackers to have any chance of working? You decide.
Oyo is a less familiar term (than bunkai) to most Karate students. I've heard several different definitions of the term. Probably the most popular is that oyo is 'what you do after you've done the bunkai', but you still need to do something to finish the assailant off. Another view is that bunkai is actually a more stylised interpretation of the kata, to be studied first, followed by oyo, which is the more practical real world way of doing the technique.
But here's the rub, both terms are actually foreign to Karate. Bunkai and oyo are Japanese words, whereas Karate - prior to the 1920s - was a purely Okinawan art. It was taught using the Okinawan language (known as Okinawan Hogen). To the best of my knowledge the terms bunkai and oyo do not have equivalents in Okinawan Hogen. Certainly Karate as a whole did not have fixed, rigid terminology. This came later as Karate-do was developed as a Japanese art. And there is no evidence that Okinawan Karate practitioners of the past made any differentiation between bunkai and oyo, regardless of whatever terminology they may have used.
So why do people differentiate between bunkai and oyo? Forgive my cynicism, but it seems to me that the most common reason is to make the person talking about oyo sound more knowledgeable, as if they are privy to arcane knowledge that the listener is unaware of. Either you understand the kata, or you don't. Either you can apply it, or you can't. Dressing it up in unnecessary terminology won't make any difference either way. So I use the word bunkai, simply because it is a term that people nowadays readily associate with kata applications. Oyo, on the other hand, is simply misleading and irrelevant.
Most people who have heard of bunkai consider it to mean 'the practical application of the kata'. I agree with this definition but prefer to refine it a little. I define bunkai as the 'practical application of the PRINCIPLES within the kata'. Kata are usually considered to be sequences of techniques, but I prefer to think of them as sequences of principles. If a particular self-defence technique (as practiced with a partner) can be considered to be bunkai for a particular kata then two basic conditions need to be satisfied:
the technique should rely on the principles embodied in the corresponding kata movement(s), and
practice of the kata should help improve your ability to actually do the technique.
These principles may be mechanical and/or tactical. This subject is explored in much greater detail in this article>.