The dangers of tewari? from Haylee vs Ten

Uberdude · #1

Antti Törmänen (aka Ten), the Finnish player who recently made 1p in Japan and Hajin Lee 3p (IGF secretary and Haylee on youtube) recently played a game on OGS (https://online-go.com/game/3668339). Haylee won, and I felt Antti made several awkward shapes, but there is one in particular which in Ten's review he used tewari to say it was reasonable for him, but I felt it was a total disaster and think he is misusing tewari to trick himself. I would appreciate your thoughts on the issue I explain below.

First here's the whole game:

The fighting immediately starts with white's invasion on the lower side. g4 feels a bit odd to me as f2 is white's sente: h5 looks potentially better as then the j4 peep is effective if white jumps to k5. Calvin Sun AGA 1p also said this in this video commentary (I only watched a little) https://www.youtube.com/watch?v=nOy8aQrlCKA. Anyway maybe Ten likes the more solid shape. But the main issue is white's move at n2 and the resulting squeeze, a standard tesuji in this shape. I think this is just too bad for black: white gets a perfect shape of thickness and eyeshape in sente whilst black gets only a few points, lost the chance to j4 peep, and p3 just looks retarded afterwards. Calvin also didn't like this, and was looking for ways for black to resist with j4 peep, or answer n2 at m4, basically anything to avoid the squeeze. However in his review (https://online-go.com/review/99482) it seems Antti was happy enough with his result below (maybe there was live audio or other context I missed, but see move 36 text comment):

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . b . . X . . . . . . . . . . . . | $$ | . . a . . . . . . . . . . . . . . . . | $$ | . . . . O . X . B . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , O . . | $$ | . . O O X . O . . O O X O X X . . . . | $$ | . . . X X O . . . . . X O X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Ten's review wrote:

Ten: I wonder, how did Haylee evaluate this result this far?
Ten: I also thought it wasn't bad for me

So even enough, as expected
Ten: Ah, sure?
Ten: Necessary for black?

Antti does concede that the marked black stone no longer has much effect on white once she got strong with the squeeze, but he did that for the aim of a. (But can't white resist that with b as Calvin also suggests, but nevermind).

Antti's review makes the following tewari argument by removing four stones:

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , . . . | $$ | . . O O X . O . . O O X a b X . . . . | $$ | . . . X X O . . . . . X c d . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Ten's review wrote:

To me, the shape is like this
And a bit thicker for black, finally
My way to evaluate it, anyway;

Playable for both; that's what I thought

He takes away the a-d exchanges, which he thinks are a little bit of a minus for white as they make black thicker, so concludes the result if ok for him. However, I have two problems with this tewari analysis: First, are those exchanges really bad for white? They make the p3 stone stupid, and there was another way to answer, namely like this:

Click Here To Show Diagram Code: [go]$$Wc $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O a . . . . . | $$ | . . O X . X X . . , . O X X . , . . . | $$ | . . O O X . O . . O O X 1 . X . . . . | $$ | . . . X X O . . . . . X 2 . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Answering this ways white's push at a is harder to ignore due to the upcoming atari (but maybe black wouldn't mind answering to make a big corner), but on the plus side L2 is no longer sente. But most importantly (?) there is an eyeshape difference on the edge: black is more alive: with the game sequence if/when white comes into the corner and a sequence like the game happens black's group has to worry about making two eyes if he were to play 6 on the outside:

Click Here To Show Diagram Code: [go]$$W $$ | . . . . . . . . . . . . . . . 6 . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . 4 2 . . | $$ | . . O . . . . . . . . . . . 5 3 . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , 1 . . | $$ | . . O O X . O . . O O X O X X a b . . | $$ | . . . X X O . . . . d X O X . 7 . . . | $$ | . . . . . . . . . . . . c . e . . . . | $$ +---------------------------------------+[/go]

Here black can actually live with a-e (which is pretty miserable), but if white can exchange the extension first like below it might even be dead (so black would give the 2 stones, there's a timing issue here):

Click Here To Show Diagram Code: [go]$$W $$ | . . . . . . . . . . . . . . . 6 . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . 4 2 . . | $$ | . . O . . . . . . . . . . . 5 3 . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , 1 . . | $$ | . . O O X . O . . O O X O X X . . . . | $$ | . . . X X O . . . . . X O X . 9 . . . | $$ | . . . . . . . . . . . . 7 8 . . . . . | $$ +---------------------------------------+[/go]

However, if black had answered the cut (in our tewari sequence) with the atari from below then black is definitely alive:

Click Here To Show Diagram Code: [go]$$W $$ | . . . . . . . . . . . . . . . 6 . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . 4 2 . . | $$ | . . O . . . . . . . . . . . 5 3 . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , 1 . . | $$ | . . O O X . O . . O O X O . X . . . . | $$ | . . . X X O . . . . . X X . 8 7 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

So first of all I don't buy the tewari argument that those 4 exchanges were a clear loss for white, they could also be viewed as a probe which black answered in a way which means he is less sure of having 2 eyes later so white's invasion of the corner has more attacking power.

Anyway, my bigger problem with Ten's tewari argument is that he took away 4 fairly incidental stones, but ignored the far more important earlier ones! He takes as his starting position, one which he presumes to be largely even, the below:

Click Here To Show Diagram Code: [go]$$W $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , . . . | $$ | . . O O X . O . . O O X . . X . . . . | $$ | . . . X X O . . . . . X . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

But just by intuition this looks great for white to me: black is overconcentrated whilst white has a nice outside. If we could move p3 to r3 that'd make it better surely? But how about applying tewari to this position to see how we got here from the game

Click Here To Show Diagram Code: [go]$$W $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O 5 . . . . . . | $$ | . . O X . X X . . , . 3 4 6 . , a . . | $$ | . . O O X . O . . O 1 X . . X . . . . | $$ | . . . X X O . . . . . 2 . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Here is the one sequence I propose. White, concerned about the double peep, buts at 1, probably a bad move. But then black answers very submissively at 2, instead of standing at 3. White then plays the vital point of 3. Black answers at 4, another slow move that is not necessary, instead he could tenuki or play something like a to make many more points in the corner. White answers at 5, which is quite a reasonable move (though maybe a bit slow as not sente), as a black push here would be painful, and black defends at 6, which is quite big and consistent with 4, but again feels rather slow given the corner is open and white is already strong. This sequence is clearly good for white to me, which agrees with my intuition that the squeeze in the game sucks for black. So Ten only does a partial tewari on the minor 4 stones which are possibly a bit good for black, but misses out on tewari on the more important 6 stones which are very good for white.

Do you agree with my analysis? If anyone watched Ten's live review did I misunderstand his position?

RobertJasiek · #2

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , . . . | $$ | . . O O X . O . . O O X O X B . . . . | $$ | . . . X X O . . . . . X O X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Tewari after move 35 can be simple: the marked black stone is essentially superfluous, so Black lost one move. Instead of 35, Black should have played:

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , 1 . . | $$ | . . O O X . O . . O O X O X X . . . . | $$ | . . . X X O . . . . . X O . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Uberdude · #3

@Robert: Yes, not taking those 2 stones could be better, but I still prefer white whose group is now strong and black didn't get enough in return (his left group is still weak). I wonder if all this problem comes down to p3 and the joseki choice on the lower left: after white splits black checks from the right side with m3, but this ends up too close to p3 because after white jumps to k5 black doesn't want to jump to m5 because then p3 is too close (would be better at r3 for example), but if white gets m5 then black doesn't want to answer (could l3 be an ugly makeshift sente defence?) but if you don't defend n2 is just too good for white. Looking in ps.waltheri.net with p3 no pros play the d2 atari and then hanging connection. The most popular answer is in fact tenuki to the funky shimari at q6 (quite a few hits are of O Meien (known for his funky openings)) and that has a good winning % of the tiny sample if white then plays d2.

pwaldron · #4

To start with, I'm with you.

John Fairbairn's idea of a "Hiroshima group" (I think) seems relevant here. White has created a strong group with strong eye shape, and it's going to turn the right side into a wasteland as far as developing territory for Black. That's in addition to anything he gets in the centre.

Bill Spight · #5

Roughly even?

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . B . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . W O . . . . . . | $$ | . . O X . X X . . , . O X X . , O . . | $$ | . . O O X . O . . O O X O X X . . . . | $$ | . . . X X O . . . . . X O X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

I like White. For one thing, the exchange of :bc:

for

is good for White, I think.

Also, my evaluation function, which has a known bias towards influence, likes White. (!) :roll:

Tewari? What tewari?

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , O . . | $$ | . . O O X . O . . O O X W B X . . . . | $$ | . . . X X O . . . . . X W B . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Törmänen does tewari by pairing the marked stones.

Click Here To Show Diagram Code: [go]$$Wc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , O . . | $$ | . . O O X . O . . O O X 3 4 X . . . . | $$ | . . . X X O . . . . . X 1 2 . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

That means that he envisages this as an equitable line of play. All I can say is, You've got to be kidding! :shock:

wineandgolover · #6

Antti is Finnish, writing (not speaking) in English, about a concept that we associate with the Japanese term tewari. So let's cut him a little slack.

That said, I like white.

Calvin Clark · #7

It's an interesting opening, so I decided to check with GoGoD to see if it's been played before. Up to move 10, I found 11 games, 4 of which were played by O Meien, who (not surprisingly) chose 'a' every time, but that's his thing.

Other players have chosen 'b', 'c', and 'd'.

Antti's move, 'e', is new in this whole board position, but if just looking at the lower side, 'e' has been played but the continuation at 'g' instead of protecting solidly at 'h' was played by 2 players out of 3. Some players also played at 'i' directly without making the e-f exchange.

Another thing I was curious about is CrazyStone's evaluation at the point in question. On my machine at move 35, CrazyStone 2013 evaluates at White +7.5. (CS is weaker than either of these players, so take it a grain of salt.)

Click Here To Show Diagram Code: [go]$$ Continuations $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . d . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O b . . . . . . . . . . . a . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . O X . h . . g i . . . . . , c . . | $$ | . . f O X . . . . . . . . . X . . . . | $$ | . . . e . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Uberdude · #8

I don't think Antti's English will be a source of confusion as he's basically fluent, and we know what tewari is (and he studies Japanese too). It's possible I misunderstood his review, maybe I'll ask him. I'm now looking at 1:43:00 in the youtube review and Haylee says she also thinks the exchange of j7 for m5 is good for white. Will watch more later when I have time, now I have to play a PGETC game!

Edit: PGETC delayed, so watching more of the review. It seems I did correctly understand Antti's tewari argument, and Haylee doesn't even challenge it but "yes, that makes sense, that's a good point". I don't know if she is just being diplomatic or not bothering to analyze deeply or be critical, but I really can't agree with this tewari of 4 fairly incidental stones (though as Bill points out even that tewari is dubious) whilst ignoring the much more important tewari of the 6 stones which resulted in white getting such magnificent outside shape and thickness and black a meagre territory.

Calvin Clark · #9

pwaldron wrote:

John Fairbairn's idea of a "Hiroshima group" (I think) seems relevant here.

It's called a Chernobyl group. It's too bad NewInGo isn't up on the internet any more, though it's in the GoGoD download. I miss that series and T Mark.

Uberdude · **#10**

Calvin Clark wrote:

Another thing I was curious about is CrazyStone's evaluation at the point in question. On my machine at move 35, CrazyStone 2013 evaluates at White +7.5. (CS is weaker than either of these players, so take it a grain of salt.)

Was that with or without komi?

Calvin Clark · **#11**

Uberdude wrote:

Calvin Clark wrote:

Another thing I was curious about is CrazyStone's evaluation at the point in question. On my machine at move 35, CrazyStone 2013 evaluates at White +7.5. (CS is weaker than either of these players, so take it a grain of salt.)

Was that with or without komi?

With komi. Very early positions evaluate closer to even. BTW, by move 54 CS thinks it's a half-point game, so weird tewari or no, there's a lot more to look at later on.

Sennahoj · **#12**

Bill Spight wrote:

That means that he envisages this as an equitable line of play. All I can say is, You've got to be kidding! :shock:

I don't think that's implied, I think he means the "other" kind of tewari, "Take away an equal number of (superfluous) stones of both colors from a position" (from Sensei's)

Bill Spight · **#13**

Sennahoj wrote:

Bill Spight wrote:

That means that he envisages this as an equitable line of play. All I can say is, You've got to be kidding! :shock:

I don't think that's implied, I think he means the "other" kind of tewari, "Take away an equal number of (superfluous) stones of both colors from a position" (from Sensei's)

Well, for each player to play an equal number of superfluous stones may be silly, but it is equitable.

Also:

Click Here To Show Diagram Code: [go]$$Wc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , O . . | $$ | . . O O X . O . . O O X W B X . . . . | $$ | . . . X X O . . . . 1 X W B . . . . . | $$ | . . . . . . . . . . . . 2 . . . . . . | $$ +---------------------------------------+[/go]

The

stones are hardly superfluous, as :w1:

is atari. Even if it is not sente at this time.

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . X . X . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . O X . . . . . O . O O . . . . . . | $$ | . . O X . X X . . , . O X X . , O . . | $$ | . . O O X . O . . O O X C C B . . . . | $$ | . . . X X O . . . . O X C X . . . . . | $$ | . . . . . . . . . . . . C . . . . . . | $$ +---------------------------------------+[/go]

If he had applied tewari to arrive at this position by pairing the stones on the marked points, there would not have been that problem. After all, we expect that atari to be sente at a later point in the game. For White to play sente from the right would not be good for Black, and in the game Black took pains to prevent it. OC, in this position the :bc:

stone is questionable.

Uberdude · **#14**

So I sent Antti an email asking him for his view. He kindly replied but didn't really address the tewari argument:

Antti Törmänen wrote:

When I took the two white stones on the lower side, my main reasoning was that there are really big points left on the board (lower right enclosure and lower left pincer), and I considered myself happy enough with the result if I could get one of them.

Calvin Clark · **#15**

Uberdude wrote:

So I sent Antti an email asking him for his view. He kindly replied but didn't really address the tewari argument:

Antti Törmänen wrote:

When I took the two white stones on the lower side, my main reasoning was that there are really big points left on the board (lower right enclosure and lower left pincer), and I considered myself happy enough with the result if I could get one of them.

Thanks for asking. I am confused. If there are two big points, then they are either miai or one is bigger. The response makes sense in neither case. Or maybe it does if he is saying gote in fine here because they are miai.

Xylol · **#16**

Calvin Clark wrote:

[]... Antti's move, 'e', is new in this whole board position ...[]

Click Here To Show Diagram Code: [go]$$ Continuations $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . d . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O b . . . . . . . . . . . a . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . O X . h . . g i . . . . . , c . . | $$ | . . f O X . . . . . . . . . X . . . . | $$ | . . . e . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

'e' was played by Ogaki Yusaku against Hon Seisen in 2008-03-03.

The dangers of tewari? from Haylee vs Ten

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