Life In 19x19

I've noticed professionals playing the high chinese opening recently, and when white approaches the 3-4 from the outside black makes a low rather than high shimari as I would have expected.

Click Here To Show Diagram Code

[go]$$W
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . a . . |
$$ | . . . . . . . . . . . . c . . d . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . O . . . . . 3 . . 1 . . , b . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Does anyone know who started this and what the thinking behind it is? My thoughts are:
- compared to the high shimari it's not so easy to live at a or do things in the corner like b; more territorial.
- the black followup at c from the high shimari is weaker shape now.
- the high Chinese stone ends up looking a little odd: you wouldn't play there if you made the shimari first, but also white's 4th line approach on the lower side would be a bit strange against a regular shimari opening.
- the high Chinese stone does mean the should hit reduction at d is not so effective.
- a little more plausible for white to tenuki after the shimari as being lower is less good for a subsequent attack when black pincers, but still it's unlikely for white to tenuki at this point of the opening. But later it does mean that group has a little more breathing space if it gets cut off from the lower left corner.

Here's an example game by Iyama Yuta against Yamashita Keigo in the latest Kisei title match

I have no answer but the same pattern (with on the 3rd line) was played last week in the NHK Cup game between Ida Atsushi and Ko Iso. A video of the game can be found here. Around 3:00, the commentator for the game, O Meien, comments on this position.

Maybe someone knowing more Japanese than I do could tell us what are his thoughts/explanations on this?

The earliest version that I have is only three months old. Gu Li used the small knight's move against Mi Yuting in the Chinese city league on 2014-11-22. Black has won 8 of the 11 games in my database played since then. The large knight approach to the high Chinese dates back to at least 1984 but the normal responses were either the high shimari or the diagonal move at P4. Interestingly Tuo Jiaxi played the high shimari against Choi Cheolhan in the city league on 2014-11-22 as well. Black won both games but the high shimari hasn't appeared since. Everyone seems to have concentrated on Gu Li's new move.