Samsung Cup Game 3 questions

emeraldemon · #1

Prokofiev, I decided to pull your question into its own thread so that maybe more people will see it:

prokofiev wrote:

A question about the game:

Click Here To Show Diagram Code: [go]$$Wcm16 $$ . . . . . . . . . X . . | $$ . . . . . . . . , . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . 2 . . . | $$ . . . . . . . . . . . . | $$ . . . . . 7 0 . 5 1 . . | $$ . . , . 9 8 . . , 4 . . | $$ . . . . 3 . 6 . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$-------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm26 $$ . . . . . . . . . X . . | $$ . . . . . . . . , . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . 5 . X . . . | $$ . . . . . 2 1 4 . . . . | $$ . . . . 3 O X 6 O O . . | $$ . . , . O X . . , X . . | $$ 7 . . . O . X . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$-------------------------[/go]

This sequence in the lower right in game 3 seems much better for black (Won Sungjin) to me. Is it? The corner looks huge.

The next moves here were black moving the N6 stone with move 35, even.

See GoGameGuru for the complete game.

Here's the sgf:

I also like black's result there better, but I tend to underestimate the value of outside influence, so I'm probably not the person to ask

prokofiev · #2

emeraldemon wrote:

Prokofiev, I decided to pull your question into its own thread so that maybe more people will see it

Thanks!

Mef · #3

I'm sure stronger players than I will have a better analysis - but for me when I look at this position, I think "Black starts with about 1.5 moves in the area, and finishes in gote." So the positions I would use as a reference for "fair exchange" would be plays against the outside of 4-3 enclosures, rather than shapes from approach joseki:

Click Here To Show Diagram Code: [go]$$Wc Possible reference sequence against a high enclosure, W11 is marked $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . 8 9 . . . . . | $$ . . . . W 7 6 0 X . . . | $$ . . , . . . 5 2 , . . . | $$ . . . . . . 3 1 X . . . | $$ . . . . . . . . 4 . . . | $$ . . . . . . . . . . . . | $$-------------------------[/go]

In game, black's corner is perhaps slightly larger, but white has more to look forward to on the outside. White's position in game is probably somewhere in between this and a corner approach which would make sense given he was entering an area B had strength (but wasn't quite as strong as an enclosure)

Uberdude · #4

To analyze this position we need to take into account the whole board, particularly the lower left corner. The position at move 17 is as below.

Click Here To Show Diagram Code: [go]$$cm17 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 1 . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . a . O . . | $$ | . . . O . . . . . , . . . b . , . . . | $$ | . . . . . X . . . . . . . . . X . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After being pincered a common thing to do is jump out, such as to a, but then black plays b and grows the bottom side. Due to black's support in the lower left and on the right, this looks nice for black. So instead Gu Li dodged to the lower side. It is therefore natural for black to press the advantage on the approach stone, such as below:

Click Here To Show Diagram Code: [go]$$Wcm18 Another way $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . O . . . . . . . . . . . . c . . | $$ | . . . . . . . . . . . . . . . 2 O . . | $$ | . . . O . . . . . , . . . . . , a . . | $$ | . . b . . X . . 3 . . 1 . . . X . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This kind of approach and then dodge to make a 2 space extension on the side is seen a lot in modern go. According to the old theory, you shouldn't tenuki the one space high pincer as black gets a very thick shape with the cover at :b19:

. However, the idea now is white has miai of a and b. If black solidifies the corner with a (or c) he gets a nice big corner and thickness, but has spent 3 moves to do so (and the white stone sill has some aji) and takes gote, which means white gets to play b which makes profit and takes away the base from those 2 black stone which can no longer extend to make a base due to :w20:

. Conversely if black plays b white will play a and live in the corner giving black a wall. However, due to the 2 space extension white has established already on the lower side the wall is not so useful. On the plus side black b does unsettle the 2 white stones in the bottom left so they are owed a move later.

So taking these ideas as reference diagrams, let's look at the game. Instead of covering, black kicks, a more territorial move, inviting white to stand and become heavy, which he accepts as black is locally in bad shape. Black would like to play :b21:

one line higher to attack the 2 stones more, but does not due to the weakness at a created by :w18:

. White then lightly jumps out, loosely connecting all his stones together. Black then pushes into the knight's move with :b23:

, a crude play one would rather avoid as it strengthens the opponent, but one he is willing to make in exchange for cutting the thin 2 point jump and swallowing the 2 white stones on the right.

Click Here To Show Diagram Code: [go]$$Wcm18 The game $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . O . . . . . . . . . 9 . . . . . | $$ | . . . . . . . . . . . . 5 8 . 3 O . . | $$ | . . . O . . . . . , . 7 6 . . , 2 . . | $$ | . . . . . X . . . . . 1 . 4 a X . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black then continues with 2 more crude ataris that strengthen white, but on the plus side these mean he gets to solidly connect at :b31:

for a big corner.

Click Here To Show Diagram Code: [go]$$Bcm27 The game continued $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . 4 . X . . . | $$ | . . . O . . . . . . . . 1 O 3 . . . . | $$ | . . . . . . . . . . . 2 O X 5 O O . . | $$ | . . . O . . . . . , . O X . . , X . . | $$ | . . . . . X . . . . . O . X . X . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

In this sort of position the 1-2-3 principle says black should play :b29:

directly without :b27:

first. If the sequence below happened black would be happy as he cuts off the 2 stones with the solid connection and has not strengthened white on the outside: he has the cut at a or peep at b to look forward to.

Click Here To Show Diagram Code: [go]$$Bcm27 Black's dream $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . O . . . . . . . . 2 O 1 . . . . | $$ | . . . . . . . . . . b a O X 3 O O . . | $$ | . . . O . . . . . , . O X . . , X . . | $$ | . . . . . X . . . . . O . X . X . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

However, white would not be so generous, but would cut in sente at :w28:

which as a bonus gives black bad shape (the circled exchange is awful for black giving him an empty triangle and losing the option of cutting across the knight's move). Black then needs to defend :b27:

but his shape is poor, and the white stones have loads of aji to cause problems, such as the sequence shown. So in order to avoid this position and ensure connecting his corner through to the pincer stone, black was forced to play the crude pushing into the knight's move and crude atari. Thus white can be content.

Click Here To Show Diagram Code: [go]$$Bcm27 Shattering black's dream $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 5 . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . O . . . . . . . . 4 O 1 . . 8 . | $$ | . . . . . . . . . . . . O X 2 O O . . | $$ | . . . O . . . . . , . W B 3 . , X 6 . | $$ | . . . . . X . . . . . O . X . X . 7 . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

As another point, once the corner sequence concludes white played at :w32:

. This is an even better point (combining pincer and extension from white's wall) against the black f3 stone in the lower left than one space to the right which arose in the reference diagram. However white does owe a move at a and b and can only get one of them. White chooses to fix b, so black pulls out his cutting stone and a new fight develops. Also quite soon after black played at c which struck me as a rather slow move. My take on that is it not only added support for the centre fight that developed when black pulled out his cutting stone, but it also patched up some aji of those white stones in the corner that weren't quite dead yet, for example d-e-f-g-h. So when you thought black had a big corner, maybe it wasn't actually as big/safe as you thought so black had to take gote again to totally secure it.

Click Here To Show Diagram Code: [go]$$Wcm32 The game continued $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O b O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . c . . . | $$ | . . . . . . . . . . . . . . . . g h . | $$ | . . . . . . . . . . . a . O . X f . . | $$ | . . . O . . . . . . . . X O X . . . . | $$ | . . . . . . . . . . . O O X X O O . . | $$ | . . . O . . . . . , . O X . . , X d . | $$ | . . 2 . . X . 1 . . . O . X . X . e . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

prokofiev · #5

Wow, thanks Uberdude for the great comparisons and especially the last two diagrams.

ez4u · #6

The shape in the lower right is a known, though not widely used, one that appears a few times in GoGoD, going back to the forties. However, it does not appear to have been used with the high one-space pincer before. See below for reference. The fact that in the game, the equivalent of the marked stone below was tighter at "a" and that Won reinforced the right side (Q9 in the diagrams in the previous post) may have helped Gu to decide to play this way.

Click Here To Show Diagram Code: [go]$$Bc Kong Jie (White) - Wang Yao; 2009 China Weiqui League 2009-07-04 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 0 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . 6 4 O . . | $$ | . . . . . . . . . . . . . 5 O 3 . . . | $$ | . . . . . . . . . . . . 8 2 1 . X . . | $$ | . . . . . . . . . . . . . 7 9 . . . . | $$ | . . . O . . . . . , . B a . O , X . . | $$ | . . . . . . . . . . . . . . O X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Uberdude · #7

An Younggil 8p has just reviewed this game over on GoGameGuru (http://gogameguru.com/commentary-won-se ... msung-cup/). He actually said Won's reinforcement at q9 was a mistake as too slow

. It also included the elegant sequence below which shows why black had to push into the knight's move to cut.

Click Here To Show Diagram Code: [go]$$c Can't cut this way $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . O . . . . . , . . . . X X . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . O . . . . . . . . . 4 . . . . . | $$ | . . . . . . . . . . . . O 1 5 O O . . | $$ | . . . O . . . . . , . . . . . 6 X 2 . | $$ | . . . . . X . . . . . O . X . X . 3 . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Samsung Cup Game 3 questions

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