Yeah, I've been up to a little too much booze and not enough training myself. Our dojo closed for a couple of weeks around Christmas. to my chagrin, and now that I am (finally) officially a college graduate, I admit that I have been prolonging the celebration a bit too long, and am looking forward to getting my lazy ass back on the mat!
Anyway, thanks again for providing the fuzzy white rabbit for me to chase. I have not had to the opportunity to investigate my inquiries further, but in answer to your questions about udefuri and udefuri choyaku, they are basic ki society hitori waza, that most directly come (martially anyway)from our standard multiple person randori throw, where uke is generally coming to tie nage up by grabbing both shoulders, and nage throws by sort of leading one arm down and the other arm up while throwing along the same direction that uke is coming (zenpounage). But after rereading the previous sentence, I think that I'm misrepresenting the throw a bit, because the feeling and emphasis are very much an up (catch uke uperside), then down, as opposed to feeling like you are splitting uke with his/her arms, and really using the back arm to lead uke over the dropped hand, at least not unless that is what you need to do in situations like I often find myself where things are a little less than ideal
. This way, though, would not be at least for ki society be ideal, especially for "taigi." But that's a different discussion entirely.
But for the hitori waza, for udefuri the arms start at shoulder level, in a zombie/frankenstein's monster-esque pose, then both arms drop to the left, then to the right. When swinging left, the left arm naturally wraps a little around your backside and the right arm comes to the opposite hip, then vice versa. When the arms are in the center or neutral position, they should be a little wider than shoulder width, and the same distance between the arms should be essentially maintained throughout the exercise. But the center position is only really acheived at the beginning of the exercise, when on "ichi" they drop to the left, and on ni swing across to the right side in a continuous arc. The key here is relaxation and harmony with gravity.
The choyaku, or "skipping" version, involves a deep hanmi, and nage sort of cuts as if drawing a katana and cutting at neck level, and then spinning around that point. The turn has a tenkan feel in the hips and the feet. This motion is better exemplified in basic versions of katatekosadori kokyunage, or cross-wrist grab skill-throw? . We have a link to this throw on my college aikido club website, taking with a digital camera that took about fifteen pictures throughout the course of the technique. It can be seen here: http://www.ku.edu/~kiaikido/gallery/content/jasonkokyunageseries.jpg
This is perhaps not the best example, but if you look at the first couple of shots as nage enters, that is basic udefuri choyaku, except in hitoriwaza nage begins with his hand on his hip, not extended for uke to grab, so of course the sword cutting first action is not demonstrated in the kumi waza. But, if you pay attention to nage's hips and footwork, this is the same as hitori waza, but in hitori waza there we don't do an armswing like in techniqe. Instead. the arms stay level to the ground, extended but definitely with the hands a bit in front of your shoulders, ie less than 180 degrees between your arms, more like 120-150 but can differ according to body type IMO. Basic ki tests should be applicable and passable at all logical points both in the hitori waza and kumi waza of these related techniques.
Wow, it's really hard to explain alot of this stuff online, let alone in person, which is challenging enough! But if this serves as a little insight or to illuminate some differences in training methodologies then cool. I'm always frustrated when I get on aikido forums and I can't decipher what's being discussed, as if they were speaking a foreign language. Go figure!
So anyway, I gave a go at explaining what I was talking about. Hope it made a little sense. Time for more training and less "talk-kido".