Something I've noticed in pro games over the month or two, particularly Korean, is this variation on a classic joseki, 7 being one line further than the normal solid one space jump at a. I also saw Park Junghwan 9p doing it on the 4th line at b. I've not read/heard any commentary on this new trend, but I imagine it's trying to be a bit more efficient, and as white played the hanging connection of 6 the attachment at c isn't working so well yet as black can hane on the outside and gets a useful atari. I don't think I've seen this further, thinner moves with the solid connection for 6. I don't think I'd be alone if reviewing this move in a weaker player's game I said "Hmm, that's a bit strange, you leave some bad aji there, probably better to be solid one point jump (or the other joseki moves there like peep if the situation warrants it)". One game Lee Sedol as white did use the thinness to good effect later (I'll try to find it), it will be interesting to see how it develops. There are some older instances of it (e.g. 1995, 2008 from quick check on ps.waltheri.net) but it seems to be popular lately, I wonder why.

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . . |
$$ . . . . . 6 . . . |
$$ . . . . . . 4 . . |
$$ . . . . . 2 3 . . |
$$ . . b . . , 5 . . |
$$ . . 7 a c 1 . . . |
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ ------------------+[/go]

Park Jungwhan doing it on the 4th line. It seems rather painful/inefficient when he answered with the iron pillar, but he then used that to jump further into the centre.

Also I've seen a lot of tenukis after so the evaluation of this line in the context of more active black openings might be changing.

It is indeed interesting. I have seen a similar move when white plays further out, as below. A Takemiya game comes to mind (colors reversed). But in those cases, it is a little easier to see why it works and is more efficient. For me, at least, it is more difficult to judge with the hanging connection.

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . 6 . . . 4 . . |
$$ . . . . . 2 3 . . |
$$ . . b . . , 5 . . |
$$ . . 7 a c 1 . . . |
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ ------------------+[/go]

And Park JS 7p used it against Lee Sedol 9p just yesterday (in a Korean Baduk league game?, was broadcast on WBaduk):

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . 5 . . . . . 7 . . . . . . . |
$$ | . . . 2 . . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 6 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 0 . . |
$$ | . . . . . . . . . . . . . . . 8 9 . . |
$$ | . . . 4 . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Click Here To Show Diagram Code

[go]$$Bm11
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 7 . . . . . . . . . . . . . . . |
$$ | . . . . . X . . . . . X . . . . . . . |
$$ | . . . O . . . . . , . . . . . , X . . |
$$ | . . . . . . 0 . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 5 . . |
$$ | . . 9 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 6 . 4 . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 2 . . . |
$$ | . . 8 . . . . . . . . . a . . . O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . O . . . . . , . . . . b , 1 . . |
$$ | . . . . . . . . . . . . 3 c . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

In this game nothing much happened with the thinness: later black jumped at a and white exchanged b for c and the push and cuts below b gave white some nice little bits of yose.

P.S. Can't find the other Lee Sedol game with it in go4go, maybe I misremembered the players or they don't have it. It was at the black top right corner, anyone else see it?

A faster movement leaves behind a greater weakness so that a reinforcement can become necessary more easily. Hence, this is just a fashion and need not be viewed as a joseki change.

Maybe not a change, but if it sees significant play(and did not before) some dictionaries might need to add it as an extra line in their new editions.

By that logic the Shin Fuseki and sanrensei were just fads and not real fuseki.

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Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Exciting joseki gets boring.

Haha. Reminds me of the SNL character Debbie Downer.

Pro plays it -> efficient

Kyu plays it -> mistake

(deleted, accidental double-post)

What fascinates me about this game is the life and death problem in the top right corner.

I assume the black group in the top right was killed and immediately had to resign because white now has an unassailable 30 point lead, but that problem is way too advanced for my pitiful skills. I can't see how he is dead at all. I get lost just trying to start; it feels too vast, like I'm just playing random moves. Anyone have any variations on it, that I could study? (If not, I will keep hacking away at it.)

If I'm wrong and that's NOT what happened, what did happen? I'm still struggling to learn here.

I don't see a clear kill necessarily, but what I do see is most of black's expected corner points disappearing. Counting the rest of the board and prisoners, black has surprisingly little territory... maybe 45 points. Ignoring the entire top right again, white has about 50 points on the board, plus komi. I imagine black expected to have enough points in the top right to keep him in the game if not win, but now it seems unlikely that he's going to get a lot more than 2 points here, while white will pick up quite a few, and most of the other big endgame moves have all happened already.

Right, it's not a kill, just good endgame.

I noticed this game which may have some relevance, apart from the very impressive result from a name I haven't heard yet, we get to see a variation of discussed joseki in the upper right corner:




EDIT: Oops, wrong SGF, fixed

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Tactics yes, Tact no...