We don't use many Japanese terms, so I'm not at all sure what your first sentence is about. If you translate those for me, maybe I can clear up what I said earlier.
The second paragraph, I agree with entirely. That's where the "void" is. If the attacker pulls back hard, he falls hard. If he stiffens his arm he opens up other techniques, and I have more leverage for some moves (and joint locks generally hurt worse/become more destructive).
Jerry, no worries. Sometimes the Japanese, with its layered meanings, actually works better, sometimes not.
Only three fundamental wrist locking "positions," if you will.
Gaeshi (typically associated in wristlocking techniques with kote-gaeshi) can mean, depending on who is doing the translation as "reverse" or "turn."
A very simple way to see/feel kotegaeshi happening to you is to extend your right arm out in front of you, palm up. Keep the palm up and then bend the right elbow so your right hand gets closer, still palm up. Then reach across and grasp the right hand with the left one, fingers going around the back of the hand and grasping the base of the right thumb, and then attempt to twist your right hand at the wrist to get your own thumb to point down at the ground. That's a simnple kote-gaeshi.
Hineri is the rotational opposite of kotegaeshi.
Put your right arm out in front of you, palm up again to start. Then rotate the right hand counterclockwise so that the right thumb first points left, then down, then try to keep rotating it until you have to let the elbow bend to allow it to get any farther. Once you get it so that your right thumb is again pointing to the right, you've most likely got a bent right elbow (unless you're really flexible at shoulder and wrist). Now, imagine Segal grabbing your now downwards-pointing fingers at their base (which includes the hand itself), and both lifting and pushing the hand back into your body (consider it a scene from... I think it was Hard to Kill, he's making a mean face while he's doing it). This interesting sensation is kote-hineri.
Mawashi is actually a compression lock on the wrist.
Same start position, right hand out in front of you, palm up. Rotate it over until the palm is now facing down. Keeping the palm facing directly downwards, pull the hand back by bending the elbow, right hand at shoulder height in front of the right shoulder. Reach across the body and put your left palm on the back of your right hand, at the knuckles. Don't let your elbow go anywhere so you can feel the compression start to get uncomfortable as you press firmly downwards... mawashi.
All three fundamental locking positions can be achieved in a myriad of ways, front, back, this side, that side, inside to out, vice-versa, but the basic "locked" positions of the wrist are anatomically defined. And of course, you can vary them to get a combination of effect as well.
I'm sure you guys do this stuff, it's just names. We could call it Smooth Orange Peel Lock if we wanted. it's just that nobody else would know what we were talking about. For instance, you used the word "void" above where I generally say "hole." Judo background, talking about holes. So, when students are having a hard time with a wrist lock/submission, I usually start out the conversation with something like, "Well... which lock is the end of that, what you are going for?" The proper response from my people is one of the three words above, gaeshi, hineri or mawashi.
