This has been an ongoing play against the Low Chinese since early last year. I believe the first time I saw this in a pro game was in April. This game between Ahn Kukhyun 4p and Shin Minjun 1p - it was just a random game that I reviewed that day along with other matches by more prominent players like Park Jungwhan and Lee Changho, but I remember how surprised I was the first time I saw this.

Now, it is getting old. I'm starting to have to play against it in my own games because I almost always play the Low Chinese as black. On the plus side, I've memorized this invasion joseki really well. Here's a game played a couple days ago that featured the invasion.

Click Here To Show Diagram Code

[go]$$B Zhao Chenyu 3p (B) vs. Xu Jiayang 2p (W) - 2/11/2014
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X O O . . |
$$ | . . . . . . . . . . . . . O X X O . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . O O . |
$$ | . . . . . . . . . . . . . . . X X X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

And here are some examples of games from the last year that feature this early 3-3 invasion as well:
Tang Yi 2p (B) vs. Qiu Jun 9p (W) - 4/10/2013
Yu Zhiying 4p (B) vs. Chen Yiming 2p (W) - 5/14/2013
Guo Wenchao 5p (B) vs. Ke Jie 4p (W) -7/7/2013

I see everyone doing this. From 9 dan to 1 dan. When I reviewed three games from the last couple of days that had the Low Chinese I saw that all 3 featured this, and I was shocked at the game where white made the Low Chinese and black chose to invade the 3-3 again!

Click Here To Show Diagram Code

[go]$$W Xie Ke 1p (B) vs. Li Qincheng 1p (W) - 2/12/2014
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O O X . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | . O O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Is this invasion really that strong against the Low Chinese? And why was this not played until recently? I've just finished the second chapter of The Chinese Fuseki by Kato Masao, the chapter on approaches to the 4-4 stone, and this move is never mentioned - as if invading the 3-3 is just too silly to think about. Instead, it talks about white playing the old-fashioned slide move, which I see less, but is still played today by pros.

Does anyone know the reasoning behind this 3-3 invasion fixation that pros suddenly have when facing the Low Chinese?

_________________
"You have to walk before you can run. Black 1 was a walking move.
I blushed inwardly to recall the ignorant thoughts that had gone through
my mind before, when I had not realized the true worth of Black 1."
-Kageyama Toshiro on proper moves

Have you done any number crunching research? You could take all the games that feature the move and determine the percentage of time the player using the invasion end up winning. If they are winning more often than not, then that would explain its adoption. It would probably make sense to only analyze games with smaller rank differences.

If you do end up doing research I'm curious as to the results. I might even try and put something together ;D

I'd love to be able to do that, but I don't have access to GoGoD or any other go database software. My "research" into this move has basically been reviewing the pro games that I've come across on Go4Go.net. I posted this because it seems like I've been seeing it a lot. When I realized that today's review session featured 3 Low Chinese games and all 3 had this, I wanted to see if others had done that sort of research.

From my own subjective experience it seems like the win-rate is about 50-50 from this. It doesn't seem like white wins more than black. However, again, I don't have access to hard data.

_________________
"You have to walk before you can run. Black 1 was a walking move.
I blushed inwardly to recall the ignorant thoughts that had gone through
my mind before, when I had not realized the true worth of Black 1."
-Kageyama Toshiro on proper moves

I've read Kato Maso's book and this joseki is not in it, in actuality this is the first time I've seen it played.

It seems like it favors white as he finishes off with sente which he could follow up with something like N4. Also that approaching stone in the top right still has a lot of use left in it.

Perhaps black should pincer that approaching stone instead or use a knights move instead of a one space jump down the side.

Yeah, I have Smart Go but doubt the database included is up to date enough to have a significant number of games if it's a newer trend. I do have some Access and SQL experience. Maybe it might be fun to try and mine some data if I can find the time! If it really is 50-50 then it could just be the fashionable move for today

You've piqued my curiosity for the challenge of what kind of data I can analyze. I know Smart Go can analyze Fuseki and also pattern match localized positions. I suppose if I could output results to Access I could spit out some usable info. If I come up with anything, I'll let you know.

My copy of GoGoD (games up to the end of 2012) has 8 instances of this invasion for White (Cho Chikun responsible for 3 of them). The first is from 2005, see attached:



The rest are all in 2012. For the tiny sample: B: 62.5% for what it's worth.

I believe the innovation that has made this move popular is not so much the 3-3 invasion itself but more the immediate push at o18 afterwards because if black hanes to put pressure on those outside two stones then white has q19 in sente so his corner is already alive so he has fast development (and if black extends white has to live in gote but in exchange his outside stones are stronger). Another basic idea is that for move 11 it is slack for black to block the right side and take sente as then it is equivalent to white playing the slide, black tenuki, and then white later playing 3-3 and black blocking immediately which is a slow move as that exchange is good for white. Another idea is that after the 3-3 invasion black's r9 stone can be considered too close to the wall above as it is still fairly easy for white to approach at q5 and settle (space to extend to r7 in the standard sequence). Given this upper right sequence black would probably prefer to move r9 to r8 to make it harder for white to come into the lower right corner which is partly why this runty chinese opening has also become popular recently. I've not checked GoGoD but I doubt you'll find the 3-3 invasion with r8, instead the inside approach is normal.

P.S. check the commentaries on gogameguru.com, some of those feature this opening.

I was going to say it was probably Cho Chikun's fault. I've noticed strategy books tend to be a little biased towards strengths of a line of play, and only occasionally mention weaknesses, however I get the impression that corner invasion joseki are considered kind of basic. Anyway, everyone who plays the 4-4 should know, it's not about the territory in the corner.