Originally posted by akiy
Interesting. What would be, in your thoughts, the differences between pinning your uke and controling your uke's escape exits?
I would say that a pin is when you apply pressure to part of uke's body, and the direction he needs to move in to release this is blocked by the mat. A standing kotegeishi finish is a good example of this, and the standard nikkyo/sankyo finishes. Its a literal 'immobilization' of part of the body.
The other case (let's call it a supression) is when uke is not immobilized per se, but cannot get up because they can't get any leverage against the mat, or the direction they can get leverage (their escape route) is blocked by tori's centre. O-sensei's "drawing a circle of ki around uke", the kokyu ho ending, or just holding someones hands is this type of control. Another nice example is in the middle of a big slow traditional iriminage, where uke is thrown to the ground, and the only escape they have is to come back up/turn towards tori, and receive the second half of the technique.
The standard ikkyo finish can (IMO) be done in either way. What you can't do is half a pin and half a supression, which I think is where a lot of beginners have trouble.