I haven't found my copy of "Aikido and Judo" yet (aka "Judo Appendix: Aikido") but I did attack some of your questions using another book - Aikido:Tradition and the Competitive Edge by Shihans F. Shishida and T. Nariyama.
David Sim wrote:
Does anyone know of a good account of Tomiki's development of the randori no kata (and his system of classification of techniques in general) and an explanation of why it is how it is?
From my understanding Tomiki approached the concept of Aikido waza from the position of traditional Jujutsu (much like Kano did with Judo). I believe he looked at the whole mass of traditional Jujutsu waza (atemi-striking, kansetsu-joint, katame-restraining and nage-throwing) and created subdivisions based on the critical effective element of each waza. Prior to his work with Aikido he already had Kano's body of work as well which had already focused on the katame, nage and some of the kansetsu waza, so it is very likely that the initial classification of waza I gave above may have been somewhat set by Kano's initial work when developing traditional Jujutsu into Judo.
The reason it is the way it is may also have something to do with Kano's research. As seen on the JAA website Boon gave, Tomiki saw the difference between Judo and Aikido waza as being primarily determined by the distance or ma ai being used. When at arm's length, Aiki waza was more suitable, when at a closer, body to body, grappling range, the Judo waza appeared to be more suitable.
With this in mind if we look at the Randori no Kata we see a progressive movement from striking range (Atemi Waza
) to Kansetsu waza (grasping range) which is broken up into Hiji Waza- (elbow techniques-mainly deployed using the forearm as a lever to manipulate the natural bend in the elbow joint)
and Tekubi waza (wrist techniques-mainly deployed using the hand as a lever to manipulate the natural bend in the wrist joint).
At the end of the kata we have Uki Waza ("floating" techniques-utilizing precise timing combined with focused and coordinated body movement to throw via kuzushi)
. I can see why the Uki waza is at the end because although it involves the joint manipulation found in Kansetsu Waza, it is critically dependent upon timing and coordinated power (toitsu ryoku and kokyu ryoku) to be effective.
If you have seen some of the basic Judo kata it is actually very similar in concept to how Tomiki has the Randori no Kata laid out, except that the Judo practitioners start from within grappling range (holding onto each other), take 3 steps together and execute on the 3rd step instead of walking up to each other in 3 steps and then executing as Aikido ma ai is reached on the 3rd step. Again here ma ai is a deciding factor on how things operate.
David Sim wrote:
In particular, did he produce a complete classification of which the randori no kata is the subset of techniques that are judged 'safe' for competitive training? And to what extent is the randori no kata (or the ur-kata of which it is a subset) an exhaustive list of ways of manipulating the body 'in an aikido way'?
In Shodokan the Randori no Kata is fundamental as it teaches the core basic techniques which can be used to extrapolate and develop the vast majority of Aikido waza. In this way one does not need to experience and practice every single Aikido technique to learn it, but one masters the core movement principles of all Aiki waza and is able to utilize these principles in the infinite scenarios based on type of attack, omote or ura, grab, punch or kick etc.
From my own experience training with Aikikai instructors I can vouch for the above, having practiced waza that I had never experienced, but with the basis of the randori no kata it was no challenge to adapt to the particular waza being taught. I can even go as far as to say this has also assisted me in learning Jujutsu technique as well.
The Randori no Kata however still is a basic template of the waza allowed in Shodokan Randori and Shiai. This is the case with any system that has a competitive aspect. If there are rules there must be something that indicates what is and is not allowed. This applies to Karate, Judo and Kendo also. However, since the Randori no Kata is not the only Shodokan technical library available (we have the Koryu no kata etc.) there are ways to experience a great variety of all the Aikido waza through the practice of other kata as well as developing oyou waza (application techniques) etc. whether they be allowed in shai or not.
David Sim wrote:
And in particular, why are there precisely those three uki waza? Are they the only posible ones?
Like the rest of the Randori no Kata, the 3 Uki waza are merely fundamentals of how one uses total body coordination and timing as a primary element in applying Aiki waza. From those 3 waza there are many permutations. Here are some examples:
Mae Otoshi: This uses a powerful hip/stance change while stepping, channeling one's power through the upper arm or shoulder into the back of Uke's elbow. The same identical movement (footwork alone with focus of power through the shoulder/upper arm) can be used to throw an attacker from a two handed bear-hug type grab from behind. This does not look like mae otoshi (called kokyu nage by other schools), but directly uses the principle of mae otoshi.
Sumi Otoshi - This principle can be applied against a hook punch by entering strongly into the bent elbow and utilizing one's own chin as the focal point to channel the downward force of one's entire unified body into the Uke's inner elbow and weak line, causing Uke to fall backward like traditional sumi otoshi. Again this uses pure footwork and body alignment without the use of hands and "looks" nothing like sumi otoshi from the Randori no Kata, but works in precisely the same manner.
Have fun playing the the kata. I hope this has helped.