Japanese paper on the technical development of kouchigari

Technical historical paper tracing the development of kouchigari from the days of two points bouts and how it has changed.

English abstract at the end.

https://www.jstage.jst.go.jp/article/budo1968/19/1/19_50/_pdf

So, what does anyone think of the notion that it evolved to gain points versus ippon?

I agree with his opinion in english text.

I agree with opinion, that it is good Waza for continuing in Newaza (Osaekomi waza) too. I like Ashi waza - lot of quick, suprisingly technigues with minimum risk during attack. In my view (for me) is difficult gain ippon with Kouchigari. Kouchi gari is very often used as starting technigues for Renraku waza - force opponent to do any reaction.

I agree with you Noboru, but I have seen a number of videos where kouchigari scored ippon.,in most of those throws tori was able to drive uke's head backward by pushing up under the side of uke's jaw.

You are right though as most often kouchigari is used as the initial part of a combination.

Udon wrote:I agree with you Noboru, but I have seen a number of videos where kouchigari scored ippon.,in most of those throws tori was able to drive uke's head backward by pushing up under the side of uke's jaw.

What also helps is using the whole hip (or even the whole body) for the reaping action. Apparently if done right, both of uke's legs should get displaced.

This is according to my understanding and with a big caveat that I'm no expert at ko-uchi-gari.

Linking this topic to a neighbour thread on bunkai, I remember there is a Karate kata technique that has the ko-uchi-gari leg action with a thrusting action.
EDIT: It is Goju-ryu's kata Seiunchin - see the technique at 0:59 below:

Can you explain the video's correlation to the technique.

It is not easy to see, for it is not a big and fast motion in the video. At the 59 second mark, she did a leg reaping action that emphasised whole-body movement. Now this is a kata demonstration, so the technique is not exactly what one would have done if one was to really reap an opponent's leg for a ko-uchi-gari.

This was posted just to draw a parallel with another thread which discussed the concept of bunkai. I felt it opportune to link it here with a ko-uchi-gari application.

If you ask me what is the whole point of this? And, no, I'm not saying all judoka should go learn karate kata. It is that solo exercises have their merits, particularly for techniques such as ko-uchi-gari (and foot sweeps), where one needs to work on whole-body movements especially on how to use the hip effectively.