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 Post subject: I got everything I wanted, but no lead - Please review
Post #1 Posted: Sat Sep 02, 2017 7:30 pm 
Dies with sente

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I made a major blunder at the end of the game, but I don't feel bad about it because I would have never seen it in 10 moves. I definitely learned something from that. Other than that, I got everything I wanted this game with two handicap stones, but things were still pretty even. What were my major mistakes?

Thanks for the review.



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Post #2 Posted: Sat Sep 02, 2017 9:21 pm 
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Hi negapesuo,

:b8: Good.

:w9: Probably push at R16 once, first.

:b26: Not good. ( Why did you play it ? ) Just get out, N14 or o14.

:b30: o13.

:w31: R16.

:w33: S16...

:w57: R19.

:w61: R19. ( Locally, o9. )

:w73: mis-click ?

:b78: C2.

:b88: H17...

:b94: Why. You're hurting M3.

:w95: L2. You're hurting yourself.

:b96: L2.

:black: 106 Did you consider K7 hane.

:black: 112 Reading required between K10 v. K11.

:white: 137 M5. B all dead...?

:black: 250 Why.

:black: 272 C15.

:black: 304 A18.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #3 Posted: Sun Sep 03, 2017 11:47 pm 
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white's second move gives away the sente you had on your first move. any simple kakari instead will keep sente. sente is worth about 30 points in the opening, so your second move lost you 30 points.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #4 Posted: Mon Sep 04, 2017 12:16 am 
Judan

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djhbrown wrote:
white's second move gives away the sente you had on your first move. any simple kakari instead will keep sente. sente is worth about 30 points in the opening, so your second move lost you 30 points.

White's first move also gave away sente, so shouldn't he be 60 points behind after move 2?

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #5 Posted: Mon Sep 04, 2017 4:07 am 
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a move in an empty corner is sente.

as any reader of this forum can tell you, Uberdude is a specialist. empty corners are special too, so it logically follows that

proof, as if any were needed, that the road to hell is paved with good intentions

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #6 Posted: Mon Sep 04, 2017 5:21 am 
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djhbrown wrote:
a move in an empty corner is sente.


Nope.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #7 Posted: Mon Sep 04, 2017 5:35 am 
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djhbrown wrote:
white's second move gives away the sente you had on your first move.


By "you" I guess you mean White. White's second move does give up sente.

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any simple kakari instead will keep sente.


False. A kakari may keep sente.

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sente is worth about 30 points in the opening,


False. Sente in the opening is worth about 7 points.

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so your second move lost you 30 points.


False. White's second move has an opportunity cost of around 14 points. But it gains around 14 points, so any relative loss vs. par is small, not worth considering at the level of the players.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #8 Posted: Mon Sep 04, 2017 6:17 am 
Judan

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djhbrown wrote:
a move in an empty corner is sente.
as any reader of this forum can tell you, Uberdude is a specialist. empty corners are special too, so it logically follows that
proof, as if any were needed, that the road to hell is paved with good intentions

As Bill points out, pretty much everything you wrote was false, but if we remain in the alternate universe in which sente in the opening is worth 30 points (whatever that actually means, we've discussed this before) then I was actually rather hoping you would say that the flaw in my profered reasoning was that black's 1st move also gave away sente when he had it, so he lost 30 points by doing so too which cancelled out the 30 points white lost. Saying playing in an empty corner is sente was a surprise! I suppose if there are an even number of empty corners (which there are in a 2-stone game) then you could say each pair of empty corners is effectively miai but I still wouldn't call it sente (and the claim an empty is corner is sente would break down if there are an odd number of empty corners remaining).

And of what am I a specialist and what's that about?

P.S. I feel bad for negapesuo with this thread derailment, so to actually comment on the game: white's cut at the top right was aggressive, perhaps a little overplay, but perhaps not as he has the helping stone on the top. Just so you are aware, if that fight is too difficult you can play s14 at r15. After white crawls s14 you can either hane s13 and then white lives in the corner in sente (which is easier on white as with s14 block the corner needs to live in gote) as you need to cover the 2nd line cut, or make strong shape at o16 and let white come out on the side. The latter is rather over-cautious in this position, but it's a good choice to be aware of when white has support around and the 3-3 is played as a powerful base-stealing and attacking invasion. White's press of 31 was rather thin: I want to cut it but it's complex so maybe that shows you should play r10 at q10. Also I think you tried to kill the corner too early, I want to get out as even if you killed the corner white squeezing the outside is nice for him plus losing the r10/s10 stones was very big (48 bad shape hurt them, but I'm not confident for black in the semeai even with good play), as was the 2 in the middle as they go from cutting stones to junk.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #9 Posted: Mon Sep 04, 2017 7:52 am 
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to me, sente means "if you don't reply, i will make a local gain" such as a follow-up shimari. taking a big point doesn't imply such a big follow-up move.

so, to me, taking an empty corner is sente whereas the middle of an empty side is not, since there are two sides of an empty side

everything i say is true

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #10 Posted: Mon Sep 04, 2017 8:50 am 
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djhbrown wrote:
to me, sente means "if you don't reply, i will make a local gain"


Then, Humpty Dumpty, nearly every move is sente.

Quote:
so, to me, taking an empty corner is sente whereas the middle of an empty side is not, since there are two sides of an empty side


Oh, but you can make a local gain after playing in the middle of an empty side. At least in the common parlance. ;)

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everything i say is true


By definition, apparently. :D

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #11 Posted: Mon Sep 04, 2017 2:22 pm 
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Uberdude wrote:
white's cut at the top right was aggressive, perhaps a little overplay, but perhaps not as he has the helping stone on the top. Just so you are aware, if that fight is too difficult you can play s14 at r15. After white crawls s14 you can either hane s13 and then white lives in the corner in sente (which is easier on white as with s14 block the corner needs to live in gote) as you need to cover the 2nd line cut, or make strong shape at o16 and let white come out on the side. The latter is rather over-cautious in this position, but it's a good choice to be aware of when white has support around and the 3-3 is played as a powerful base-stealing and attacking invasion. White's press of 31 was rather thin: I want to cut it but it's complex so maybe that shows you should play r10 at q10. Also I think you tried to kill the corner too early, I want to get out as even if you killed the corner white squeezing the outside is nice for him plus losing the r10/s10 stones was very big (48 bad shape hurt them, but I'm not confident for black in the semeai even with good play), as was the 2 in the middle as they go from cutting stones to junk.


Thanks, this seems to be a constant problem of mine. I have a plan and usually get what I want, but I end up giving up way too much in the process. I guess I;m not going after the right objectives.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #12 Posted: Mon Sep 04, 2017 5:16 pm 
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i am convinced that having a plan (a high-level intention) is better than not having a plan, and that planning lies at the heart of what we call intelligence, despite the successes of bots with no idea what a plan is, such as Watson and Alphago.

but it is possible to have a bad plan. two things Uberdude mentioned in his review of your game strike me as good examples of bad plans:
1. he says you tried to kill the corner too early. even without checking the game record, i am sure he is right, because that is a common kyu error
2. he mentions a couple of stones in the middle that went from cutting stones to junk - for a moment, i thought he was talking about the DeepZen-FineArt game, in which the same thing happened (see Swim's Reviews #2). in that game, and maybe in yours too, it is an example of going from bad to worse, since (a) if cutting stones die, they don't cut, so their purpose is wasted - unless they were played as "feints", as sacrifice stones, and (b) a plan to save stones that can't be saved only makes things worse. once they are on the board, they have some value even if they can't live, as they can be used as one side of a double-sided threat that forces opp to kill them while you get something on the other side. This is what "aji" means.

so, how to know whether a plan is good or not?

that's easier said than done, but there are some general principles, eg:

1. if you are ahead, play safe; and if behind, try to start a fight
2. the best form of defence is attack

at first glance, it looks like 2 contradicts 1, but it doesn't, because there are two fundamentally different kinds of attack (because every stone operates in at least two directions):

either, attack to kill
or, attack to force a defence on one side, while you build something on the other side (this is called a "leaning attack"). the shoulder-hit is a simple example of a leaning attack.

now we can see what Uberdude meant when he said "tried to kill the corner too early" because if a kill attack fails, it will be ruinous; and it will have wasted the opportunity to instead make a leaning attack - a double-sided threat that builds outside strength whilst letting the corner live.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #13 Posted: Mon Sep 04, 2017 5:53 pm 
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A minor point, but one that I thought was interesting. At move 58, black faced the board below. You played A, but I *think* B kills the corner. It's not obvious (at least to me!), but B gives black enough liberties to win the fight by threatening to make two eyes. After black B, White has to play A to prevent two eyes, and black C then forces white A again. White now has to play 2 moves in order to play T13. Below is, I think, the sequence of greatest resistance for white, and I think black can even tennuki at move 4.



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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #14 Posted: Mon Sep 04, 2017 8:27 pm 
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the position BlindGroup discusses suggests to me that both players are playing what i call "psychopath Go" - playing with only one thought in mind: killing.

i found myself wondering how they got into such a mess, each with all their eggs in one basket.

it all goes back to white's second move (move 3), which i still think is weak because it gives away sente. his first move, taking the empty corner was sensible, with which even argumentative Bill might agree.

taking an oba is what you do when you dont have a decent sente move, but after black sensibly took the last corner, white has 6 sente move areas to choose from (6 sides to kakari from, with several choices of kakari in each of the 6 areas).

so when white threw away the initiative with K17, black had a chance to seize it.

but in playing D10 black threw his chance away too! - although Go Seigen might like his san-ren-sei, and who am i to argue with Go Seigen?

black D10 is much better than white's K17, because D10 looks both ways up and down the left side, whereas K17 is just sitting there all alone, waiting to be attacked.

but D10 is gote, so white has another chance to take sente, and this time, at move 5, he does take it... sort of... but does so with an overplay.

i've seen pros make 3 space jumps and more, but to me it doesnt look right in this position, because as well as unecessarily leaving behind a weakness at M17, black has D16, so white's chances of making much at the top are not good. therefore, it would be more prudent to make a 2-space jump, or to kakari from the other side, pincering the corner stone - either corner.

black 6 is sensible. it strengthens black's potential in the upper right, and thereby also weakens K17-O17, which is why O17 was an overplay.

white follows up his blunder with an even bigger blunder - a "Jealousy Go" move, trying to steal black's corner, which is going to make black strong on the outside, making K17-O17 even weaker.

had K17 been at L17, entering the corner is locally feasible, but at this stage of the game, the top right corner is the smallest part of the board, so w should have turned elsewhere instead.

black's block at Q17 is sound. at this point, white should realise he has already made 2 blunders and gracefully resign.

but of course, not all Go players are honourable, and many carry on beserkering long after the curtain has fallen.

the sequence to white 13 is a joseki, and that's where the joseki ends; black has sente and the opportunity to build something along the bottom, or maybe to make white cry at the top.

but black doesn't do that - instead, he plays a yose move, blocking the right side which is doubly bad, because (a) it is aji-keshi, eliminating one of his future ko threats, and (b) because white already has Q4, black's potential territory on the right is smaller than his potential on the bottom. And because black already has R14, white's potential on the right is small too. The bottom side is bigger (more urgent) for both players.

so why did black play S14? what was his plan? to kill the top right??!

if the top right were killable, the joseki wouldn't be joseki.

PS can anyone tell me how to copy an eidogo record in a post so as to use it in a reply?

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #15 Posted: Tue Sep 05, 2017 2:23 am 
Judan

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negapesuo wrote:
Uberdude wrote:
white's cut at the top right was aggressive, perhaps a little overplay, .... I think you tried to kill the corner too early, I want to get out as even if you killed the corner white squeezing the outside is nice for him


Thanks, this seems to be a constant problem of mine. I have a plan and usually get what I want, but I end up giving up way too much in the process. I guess I;m not going after the right objectives.


These kind of situations with a not-yet-alive group delaying playing a gote move to live and instead cutting the 2 surrounding groups are reasonably common. As a general guideline you want to avoid the surrounding groups from getting enclosed but keep on fighting for centre access. If you kill the group but they then get several forcing moves on the outside it's often not so great, particularly if you actually have to take the dead group off the board (semedori: filling in your own territory) in a semeai instead of being able to live independently. But if they come back to live then your outside groups no longer have the option to kill to make eyes so you need to make sure if you get 2 moves in a row on the outside you are happy (with both groups).

BlindGroup wrote:
A minor point, but one that I thought was interesting. At move 58, black faced the board below. You played A, but I *think* B kills the corner.

Well spotted: that does increase liberties. So guess where would have been better for white's previous move? ;-)

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #16 Posted: Tue Sep 05, 2017 3:29 am 
Judan

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As they say, the best way to get the right answer on the internet is to post the wrong answer:

djhbrown wrote:
the position BlindGroup discusses suggests to me that both players are playing what i call "psychopath Go" - playing with only one thought in mind: killing.
i found myself wondering how they got into such a mess, each with all their eggs in one basket.

Assuming "psychopath" is meant as a criticism, I think that's too strong: plenty of good Go is about fighting, but yes this is an early brawl, but white started it with the cut so I wouldn't blame black (the OP) for tagging along.

djhbrown wrote:
it all goes back to white's second move (move 3), which i still think is weak because it gives away sente.

I wouldn't call it weak (particularly at kyu level), just not as active as an approach. In a handicap game white often wants to play an active and fast development, but plodding and calm has its merits too. Also a kakari is a very standard move which black will surely be able to play a decent standard answer to, but playing something a bit more unusual might elicit a sub-optimal response. Also as a general point for handicap (or indeed even) games, you don't always want to be playing sente moves, as if finding a good answer is within your opponent's ability then you don't gain anything (though of course you can be playing bullying sente moves which do gain a bit), whereas if you play a gote move you pose a problem to your weaker opponent: "Where is the most important place on this board, and what should you play?". They will often flub this problem and play some rubbish tiny move, giving you sente to do good moves again. This is particularly true in high handicap games in the middlegame I have found, where you have given them plenty of scaring looking bits of aji to be over-cautious about.

djhbrown wrote:
his first move, taking the empty corner was sensible, with which even argumentative Bill might agree.

I'm sure Bill would agree that was a sensible and good move, it was your claim it was sente that was wrong.

djhbrown wrote:
taking an oba is what you do when you dont have a decent sente move, but after black sensibly took the last corner, white has 6 sente move areas to choose from (6 sides to kakari from, with several choices of kakari in each of the 6 areas).

I do actually prefer to approach than wedge for white's 2nd move to be more active, but it's no big deal at 10k level. However the more general advice you are giving here that you should play a move like an approach because it is sente rather than a gote oba (big fuseki point) I disagree strongly with. There are plenty of times a gote oba is an excellent choice, and plenty of times it will be better than some approach.

djhbrown wrote:
so when white threw away the initiative with K17, black had a chance to seize it.
but in playing D10 black threw his chance away too! - although Go Seigen might like his san-ren-sei, and who am i to argue with Go Seigen?

I wasn't aware Go Seigen was a particular fan of the regular san-ren-sei, wasn't he more famous for saying he liked the diagonal one including tengen (compare to the 4-4, tengen, 3-3 he played against Shusai)

djhbrown wrote:
black D10 is much better than white's K17, because D10 looks both ways up and down the left side, whereas K17 is just sitting there all alone, waiting to be attacked.

D10 is a wonderful move, as you say looks up and down left side. Something like h17 (is this the sort of sente move you want to play?) also great, but not better.

djhbrown wrote:
but D10 is gote, so white has another chance to take sente, and this time, at move 5, he does take it... sort of... but does so with an overplay.

Not an overplay.

djhbrown wrote:
i've seen pros make 3 space jumps and more, but to me it doesnt look right in this position, because as well as unecessarily leaving behind a weakness at M17, black has D16, so white's chances of making much at the top are not good. therefore, it would be more prudent to make a 2-space jump, or to kakari from the other side, pincering the corner stone - either corner.

m17 is not a worry, even with a black stone already at h17 approach at o17 is fine (if black m17 then simple way is white o15 as sente on corner and then cover at l16). n17 2-space extension is overcautious (and liable to overconcentration). It's odd that you criticize k17 for not being sente when it's okay, but then suggest this good more sente approach is wrong. "kakari from the other side" means r14? Also good. "either corner" means c14? Dubious with d10 in place.

djhbrown wrote:
black 6 is sensible. it strengthens black's potential in the upper right, and thereby also weakens K17-O17, which is why O17 was an overplay.

Correct, except final conclusion. If black m17 white can dodge to 3-3, extend to g17 (here I'm being cautious, f17 approach could get complex).

djhbrown wrote:
white follows up his blunder with an even bigger blunder - a "Jealousy Go" move, trying to steal black's corner, which is going to make black strong on the outside, making K17-O17 even weaker.

Neither are blunders, but invading is indeed rather jealous. However, given the presence of k17 it's got some support and white may want to start a fight because he's ranked stronger. Many ways to play a handicap game.

djhbrown wrote:
had K17 been at L17, entering the corner is locally feasible, but at this stage of the game, the top right corner is the smallest part of the board, so w should have turned elsewhere instead.

k17 helps enough too, indeed white might end up thinking l17 could be too close when you descend at o18. Tenuki instead of 3-3 would indeed be good and more normal.

djhbrown wrote:
black's block at Q17 is sound. at this point, white should realise he has already made 2 blunders and gracefully resign.
but of course, not all Go players are honourable, and many carry on beserkering long after the curtain has fallen.

I presume this is a joke.
Something not mentioned yet is although q17 is good, p18 is a decision point: black can also play r16 rather than separating white. Usual continuation is s18 s17 r18 r11. Black allows white to connect the 3-3 to the approach, but avoids any cut and fight and settles on the right side. Normally this is a bit soft, but seeing as white already has k17 (which works well in the game fight) but after this sequence is somewhat misplaced (if you removed it from the board white would rather play it at f17 or o3 or somewhere else as top side not so interesting now) it has merit particularly if you want to avoid early fighting in a handicap game (of course fighting is fine too).

djhbrown wrote:
the sequence to white 13 is a joseki, and that's where the joseki ends; black has sente and the opportunity to build something along the bottom, or maybe to make white cry at the top.

Nope, black normally continues locally. Now white will normally not invade 3-3 so early, so there won't be such big opening points up for grabs so here I wouldn't criticise a tenuki (particularly o3, which could be seen as a probe to decide how to continue at top right: if white answers at r6 then right side is lower so r15 becomes to look more attractive than s14), but local answer is good too to pressure the corner.

djhbrown wrote:
but black doesn't do that - instead, he plays a yose move, blocking the right side which is doubly bad, because (a) it is aji-keshi, eliminating one of his future ko threats, and (b) because white already has Q4, black's potential territory on the right is smaller than his potential on the bottom. And because black already has R14, white's potential on the right is small too. The bottom side is bigger (more urgent) for both players.

s14 isn't yose, it's sente to kill the corner. (a) not really, there is a very real possiblity white will continue with push and cut if you tenuki; r16 is the classic kyu aji keshi here. (b) true that white q4 reduces right side black potential, but not so much to make s14 bad. Bottom side is indeed big, I like o3 for fancy probey reasons above.

djhbrown wrote:
so why did black play S14? what was his plan? to kill the top right??!
if the top right were killable, the joseki wouldn't be joseki.

Yes, s14 is sente to kill top right (even if white pushes at r15 and you block, then t15 kills, learn your L groups). That's why it's joseki (or at least a standard early-middle game sequence). This status does change if white pushes down at o18 and black plays o19 (rather than p19) to put more pressure on the outside 2 stones as then q19 being sente helps the corner live. The presence of an outside liberty (if black played one-point jump instead of knight's move) is also important here, you see this early 3-3 a lot in the Chinese opening these days.

djhbrown wrote:
PS can anyone tell me how to copy an eidogo record in a post so as to use it in a reply?

I'd download the sgf and then directly include the file contents (edited as you wish) in sgf tags.


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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #17 Posted: Tue Sep 05, 2017 4:13 am 
Judan

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Regarding move 14 s14 vs r15, here is a pattern search of the local quadrant (with k17) in pro games: http://ps.waltheri.net/827102. r15 is most common at 12 games, with 4 at s14 and no tenukis. Here's some sample games to show how the surrounding positions affect the choice of continuation.

Here black has the support of the marked black stones, so the 3-3 invasion is stealing the base of the white group and white doesn't want a fight so prudently just blocks on top of the slide and then hanes on top of the approach stone to make a strong shape. If white blocked with 1 at 2 then black's push and cut would make a very hard fight for white, quite probably one of the groups could die. Black then comes out on the 3rd line there making some territory on the lower side and preventing white sealing in the corner so white extends to 7: this makes his group stronger whilst aiming at the invasion at a. Black then indirectly defends against this whilst reaching out to k16 with the jump out to 10 (b is a probe, if white answers at b to be stronger outside then c becomes sente so the invasion at a doesn't work.

Click Here To Show Diagram Code
[go]$$Wc Yun Seonghyeon 9p (black) vs Kim Jiseok 4p; 2007
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 9 O . O . . . . . . . O X X . . . |
$$ | . . O 8 b . . . . X . . O . O , X . . |
$$ | . . O # . . 0 . . . . . . . O X . . . |
$$ | . c # # . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . a . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . # , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . 7 . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . X X O O . . |
$$ | . . X 3 . . . . . . . . . . O X O O . |
$$ | . O O . . . . . . . . . . . . X X X . |
$$ | . X O O . . 5 . . , . . . # . X . . . |
$$ | . X X . 1 O 4 6 . . # . . # O . O . . |
$$ | . . . . X 2 . . . . . . # O O . . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Here black is strong on the top side, but white is strong and has good potential on the left, so blocking is appropriate. Black pushes and cuts, rather than living directly, to give white some bad aji (presumably if 4 at 6 directly, he didn't like white defending the cut at a as white can then develop the left side nicely later). After living black immediately pulled out the cutting stone at 10 and by putting pressure on both white groups developed his cutting group and stopped white making much on either the left or top (black won by resign).

Click Here To Show Diagram Code
[go]$$Wc Choi Choelhan 9p (black) vs Lee Changho 9p; 2013
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . # . . . |
$$ | . . X X O . . . . . . . . . # . X O . |
$$ | . . X O O X . . . # . . . . O # O . . |
$$ | 8 . 6 O . 7 . . . , . . . . # # O . . |
$$ | 5 X 2 3 . . . . . . . . . . . # X O . |
$$ | . 1 O 4 0 . . . . . . . . . . . O . O |
$$ | . . . . a . . . . . . . . . . . . O . |
$$ | . . 9 . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O X . |
$$ | . . . . . . . . . . . . . . . X X . X |
$$ | . . . . . . . . . . . . . . O X O X . |
$$ | . . . . . . . . . . . . . O . O O O . |
$$ | . . @ . . . . . . . . . . . O X X O . |
$$ | . . . . . . . . . . . . . . X . X . . |
$$ | . . . @ . . . . X , . . . . X , X O . |
$$ | . . . . . X . . . . . X . . X X O . . |
$$ | . . . O . . . . . . . . . . . O . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This game seems less clear cut to me which answer is best: the main focus is black's moyo on the lower and right sides but white's already wedged it with a stone that's not weak or strong yet, so sente is important. White top left is strong, note black hasn't finished the joseki there but a could still be an aim if developing the top side. Black played block on top and then 2nd line hane, which gave white sente to help his wedge stone. Black pressed this and then white reduced again, the fighting from this then spread all the way to the top of the board and white won by resign. Lee Yeongkyu is perhaps a bit of a patient/thick player but I wonder if he was a little too patient and slack here giving white sente seeing as the top side wasn't so interesting.

Click Here To Show Diagram Code
[go]$$Bc Lee Yeongkyu 8p (black) vs Park Jinsol 5p; 2011
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 3 2 O . . . . |
$$ | . . @ . . @ . a . . . . 5 X 1 4 O O . |
$$ | . X . @ . . . . . , . . . . . X X O . |
$$ | . . . . . . . . . . . . . . . . X X . |
$$ | . . X . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , @ . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . 6 . . |
$$ | . . . X . . . . . . . . . . . 7 8 . . |
$$ | . . O X . . . . . . . . . . . . 9 . . |
$$ | . . O X . X . . . , . 0 . . . , X . . |
$$ | . . O O X . . . . . X . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Here black is strong but low on the top side, and white's wedging stone is in decent health for now. After cutting white aggressively takes the shape point at 6. This seems like a fairly balanced fight to me, and neither player would have gone for it if it was much better for one or the other.

Click Here To Show Diagram Code
[go]$$Bc Kim Jiseok 9p (black) vs Kang Yootaek 6p; 2014
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . 9 . . . . |
$$ | . . . . . . . . . . . . . 1 O . . . . |
$$ | . X # # . # . . . . . 5 . X 2 0 O O . |
$$ | . X O O O . . . . , . . 8 4 3 X X O . |
$$ | . O O . . . . . . . . . . 7 . . X X . |
$$ | . . X . . . . . . . . . . . . 6 O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , @ . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . . X , . X . . . , . . . . . , X . . |
$$ | . . X O O . . . . O . . O . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


The fighting continues for dozens of moves.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . X 6 . . . |
$$ | . . . . . . . . . . . . . X O . . . . |
$$ | . X X X . X . . . . 3 X . X O O O O . |
$$ | . X O O O . . . . , . 2 O O X X X O . |
$$ | . O O . . . . . . . . . . X . . X X . |
$$ | . . X . . . . . . . . . . . 1 O O 4 5 |
$$ | . . . . . . . . . . . . . . . . 0 7 . |
$$ | . . O . . . . . . . . . . . 9 . 8 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . . X , . X . . . , . . . . . , X . . |
$$ | . . X O O . . . . O . . O . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This post by Uberdude was liked by: Kirby
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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #18 Posted: Tue Sep 05, 2017 6:34 pm 
Lives in gote
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3-3 invasions and their continuations are so frequent, it is worthwhile for even a casual player to try to understand them a bit.

when children become parents, they usually forget what it was like to be a child, and end up arguing with their children because they have lost the empathy they need to understand where the child is coming from.

Serious scholars of Go can learn a lot from in-depth study of pro games, but most weekend golfers have neither the time nor patience nor dedication to put in the 10,000 hours of practice needed to get a swing consistent enough to be able to add the extra touches needed to be able to fade or draw the ball at will.

What does Uberdude's lengthy and detailed analysis tell us ordinary folk, without our having to do hours and hours of homework on it to tell the wood from the trees?

As he says, whether a move is appropriate depends on the situation - that's a universal truth - so, in this case, what is that situation?
Attachment:
Screenshot_2017-09-06_11-04-42.png
Screenshot_2017-09-06_11-04-42.png [ 425.52 KiB | Viewed 7248 times ]


My guess is that the value of black blocking at S14 depends on whether black already has influence over the lower right side, so that the blocking move would work with it to start to form a right-side moyo.

In the game under review, that is not the case: in fact, it's just the opposite: it's white who has a lower right side presence.

To be sure, S14 is kikashi - white has to defend at R15 - but the position after he does so is overall better for white than it was before black blocked, because:
(1) black now has one less forcing move opportunity against the top right corner
(2) black's two stone pillar (R14, S14) is more of a liability than an asset, because the forced response white R15 separates it from the ugly empty triangle Q16,
(3) Q16 is also weakened by white R15
(3) white already "owns" the lower right, negating the influence of the pillar over the right side

So black's blocking move achieves less than nothing for him and only helps white solidify his corner.

So it net loses points - more opportunity cost than value, and creating more of a liability than an asset.

negapesuo describes the game as "close" - but i would describe it as more like a see-saw, a chaotic pendulum swinging violently in all directions, only happening to end up near the middle when it runs out of space - anything but finely balanced, the commonsense meaning of "close"!

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #19 Posted: Wed Sep 06, 2017 12:57 am 
Gosei
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Quote:
would describe it as more like a see-saw, a chaotic pendulum swinging violently in all directions, only happening to end up near the middle when it runs out of space - anything but finely balanced, the commonsense meaning of "close"


I can assure you that pros will look at any amateur game this way.

Why don't you try answering the OP's question on his terms, rather than use his post to hypothesize on stuff way above your head, make unsupported claims(*) all over the place and call others "argumentative" along the way?

(*) On sente: a move is sente, in the sense that it keeps the initiative,

- in a trivial way, when the opponent locally responds, allowing you to play elsewhere without great cost
- properly speaking, when the opponent is "forced" to respond locally. No opponent can ever be forced, so the idea is that not answering locally will allow for a follow-up that makes a much greater profit than the one obtained by the opponent's playing elsewhere. A move that threatens to kill a major group is probably sente
- sometimes a move has the pretention of being sente and indeed not answering it will incur a local loss, but the offset of playing elsewhere is still positive

Probability is the key here: if we have complete information about what will happen, the notion of sente vanishes. In case we're already lost in a deterministic game, it won't make a difference whether we answer (and lose by a small margin) or not (and lose by a big margin). In a game where the outcome is undecided, one plays probabilities. Answering (and not suffering a big loss) will keep the game under control, even if it is by allowing the opponent to keep the initiative and lead by a small margin (which we don't know).

By this definition of "sente", you could argue that occupying the last corner with a 3-4 move is "sente" because it threatens to make a corner enclosure. In some situations this will be true but the opening is so versatile that you cannot simply call a move in the corner "sente". In fact, even in a situation where the 3-4 "forces" the approach, we call it "urgent" rather than sente.

It's true.

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 Post subject: Re: I got everything I wanted, but no lead - Please review
Post #20 Posted: Wed Sep 06, 2017 6:12 am 
Honinbo

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Knotwilg wrote:
Probability is the key here: if we have complete information about what will happen, the notion of sente vanishes.


Well, it may not be necessary to find perfect play, but it still has explanatory value. :)

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