Three black moves (not counting white) or two black moves and one white move?
It’s Go, so Black-White-Black. Just like in Shogi where a 3te tsume means check escape checkmate. Unless @jlt made a typo
Yes I meant black-white-black.
To count a move as black + white is a chess culture thing, not so in go.
For problem #6: I’m not seeing the tesuji. Am I missing it, or is this perhaps more a brute force reading depth challenge? Then again, 3 moves would not really suffice for such a solution (3 moves would only initiate a potential fight without showing an outcome), so I’m probably missing it.
Yes maybe 3 moves is not enough, but I’d say that after seeing 3 moves we can be reasonably confident that the fight is good for Black.
Anyway the goal is to save three black stones and an important fact is that White’s corner group is not alive yet.
Ooh, interesting ^^
Spoiler
P14, Q13, O16 ?
Edit :
Spoiler 2
(Afterwards, Black has a hane at N15 if White O15, and N17 to defend after White O14 – either before or after pushing once at N14)
Correct!
The variation is in the OJE (Play Go at online-go.com! | OGS), but it does not show what happens if white runs out his stone, which I suppose black should read out before he plays that last atari.
The variation in OJE is not the one suggested by fuseki3 or by Katago (although it also works).
Let me add two moves:
[spoiler]
White has two weak groups to defend, so the fight is probably good for Black.
I suppose the OJE variant may not work as well with that white stone already present at K17.
But even with K17 present, …
... I suppose
… I suppose white should still not try to save P15, because her corner group is not alive either.
So this might be a proper continuation by both sides?
I suppose this fight could continue for a while, marking the transition from the opening to the middle game.
Waltheri’s also has a pro game with this fight: Huang Xin (4p) vs. Huang Yunsong (6p) | Waltheri's go pattern search
All in all, I think I’d call this more a haengma puzzle than a tesuji puzzle, but the distinction is not very sharp ofcourse and puzzle categories can overlap.
At the bottom of that senseis page there is a link to a nice puzzle where the solution is a combination of tesuji and haengma.
Spoiler warning: the Haenmaui Maek link will lead to the page that has the puzzle diagram as well as solution diagram(s) of problem #7.
Problem #7, black to play.
I’d call the first move a tesuji, leading to 2 different haengma follow-ups.
The last part of the sentence above is perhaps a slight hint, so I blurred it.
From today’s Ing Cup Round of 56 Kim Eunji (B) VS Gu Zihao(W).
White’s jump at G9 was a mistake and black’s next move was the deciding move.
It’s a common tesuji that appears in life and death problems but hard to find in real games.
I don’t even know in which part of the board to play…
Focus is on the left side of the board
Not sure at all. The only point that looks like a common tesuji to me is A7 however the continuation looks quite uncertain to me. Black’s group G5 is weak, so White may escape with H3 while attacking Black. But White H6 is not completely alive either.
The direct is correct. The idea is not to take away white’s eye but to prevent white from making an eye in sente.
Since I couldn’t find the solution I looked at the game record. The tesuji is A9A10. However the normal move B9, followed by White B8 and Black B10 is at least as good according to AI. I understand that the tesuji move reduces (at least in the main variation) White to zero eye on the left side while the normal move gives White one eye, however the main focus of the game is the battle between Black’s weak group G5 and White’s two weak groups G3 and H6, and the tesuji doesn’t change that fact.
A9? The coordinates are a bit off? Are you talking about A10?
When I checked the difference between A10 and B9 is quite big, about 20 percentage points difference.
Yes sorry I made a typo, I meant A10. My version of Katago, which is only 15 blocks but still at least strong pro level (I think) says after 20k playouts: 58.6%, B+3.8 after A10 and 62.6%, B+4.6 after B9, i.e. it actually slightly prefers the normal move. Anyway the difference between the two moves is probably too subtle for average amateurs to grasp.