Two space pincer for efficiency

Knotwilg · Post by **Knotwilg** » Thu Jul 23, 2015 5:49 am

Believe it or not but recently I got the opportunity to experiment with a certain opening pattern. You may know that I will always play parallel star points, during this stage of my go career which is focused on time management, endgame and life & death.

When one of these star points opposes an 3-4 stone on the 4th line and is approached by the opponent, I found a two space pincer to be more efficient with the subsequent corner pattern at 3-4

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

Click Here To Show Diagram Code: [go]$$B Second pattern $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . 7 . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . 6 . 2 , X . . | $$ | . . X O O X . a W . . . . 4 3 5 . . . | $$ | . . X X O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ --------------------------------------- I found the White stone to be better placed than at A. What do you think?[/go]

Cassandra · Post by **Cassandra** » Thu Jul 23, 2015 6:01 am

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

Probably Black might want to play Double-Kakari with 3 ?

DrStraw · Post by **DrStraw** » Thu Jul 23, 2015 6:04 am

What about this joseki? B5 has the effect of undermining the marked W stone.

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

Uberdude · Post by **Uberdude** » Thu Jul 23, 2015 6:57 am

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

I don't mind playing black here. I might try 7 being one space further, as seems to be the pro fad currently. Yes the marked stone is better for the right, but the aji at black a is considerable (in fact I recently won a game with this opening, I lost the ko at a but got considerable profit from my threat, and by the endgame white's side was reduced to about 20 points, quite a bit less than black's two corners even though he got both bs (I answered the left one, which means white won't make much on the left side).)

MMaestro · Post by **MMaestro** » Thu Jul 23, 2015 10:09 am

I would dislike the shape since white still has weaknesses and is bordering on ippoji

Celebrir · Post by **Celebrir** » Thu Jul 23, 2015 2:14 pm

I don't like the result locally, but the important part which can be easily overlooked in such a diagram is that W has sente to play somewhere else which wouldn't be possible normally. So I guess it depends on how big the move you get in sente is. During the beginning of the opening it might be worth it, but if this would be the last moves of the opening I would try to avoid them.

Kirby · Post by **Kirby** » Thu Jul 23, 2015 3:53 pm

I don't know about the relationship with the 3-4 point, but this was discussed in an issue of a monthly Korean baduk magazine from a few years ago. There, they don't have a diagonal opening:

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

Click Here To Show Diagram Code: [go]$$Wm11 Good for black $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . 1 . O O O . | $$ | . . . O . . . . . , . . . . X X X O . | $$ | . . . . . . . . . . . . . . . . X X . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . a . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

With a one-space pincer, the shoulder hit is effective. But 'a', above, isn't as useful.

Click Here To Show Diagram Code: [go]$$ Better for white than the last one $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . O . O O O . | $$ | . . . O . . . . . , . . . . X X X O . | $$ | . . . . . . . . . . . . . . . . X X . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . W . . . | $$ | . . . , . . . . . , . . . . . . , . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Because of this, they started this whole double approach fiasco, and that was trendy (at least in the pro games I see in go magazines) a few years ago:

Click Here To Show Diagram Code: [go]$$W Trendy a little while ago $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 6 5 . . | $$ | . . . O . . . . . , . . . 3 . X . . . | $$ | . . . . . . . . . . . . . . . 0 8 . . | $$ | . . . . . . . . . . . . . . 9 4 1 . . | $$ | . . . . . . . . . . . . . . . 7 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 2 . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm11 Trendy a little while ago $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . O . . . . . , . . . O . X . 6 . | $$ | . . . . . . . . . . . . . . . X X 5 . | $$ | . . . . . . . . . . . . . 4 O X O . . | $$ | . . . . . . . . . . . . . . 2 O . 1 . | $$ | . . . . . . . . . . . . . . . 3 . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Anyway, word on the street is that this variation was too complicated and unpredictable, so pros ended up leaning toward something simpler:

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

Yada, yada, yada.

Anyway, this is different board position than with the 3-4 like in your example, but I suspect that, because two-space pincer is more efficient when the opponent goes into the 3-3, double pincer might be a good response.

Uberdude · Post by **Uberdude** » Fri Jul 24, 2015 12:40 am

In Kirby's example from the Orthodox opening, white doesn't want to activate the aji of the approach stone, because to do so means black makes a large efficient territory in the lower right based on his shimari which secures the corner (I put a common continuation on the lower left for black to lose sente):

Click Here To Show Diagram Code: [go]$$W Black develops an efficient lower right $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . a O . O O O . | $$ | . . . O . . . . . , . d b 0 X X X O . | $$ | . . . . . . . . . . . . . . . . X X 6 | $$ | . . . . . . . . . . . . c . 9 . O 3 4 | $$ | . . . . . . . . . . . . . . . . . . 5 | $$ | . . . . . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . 2 X 7 . | $$ | . . . , . . . . . , . . . . . , . 8 . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . X . . . . . , X . . | $$ | . . . . . X . . . . . . . . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Contrast this to the inefficient territory with no scope for expansion white (colours reversed in Knotwilg's example) builds if black does the same thing, as black already has a solid group in the lower right corner. The black (in Kirby's) or white (Knotwilg's) wall is unlikely to die in either example, but does suffer from being chased a bit.

Click Here To Show Diagram Code: [go]$$B Second pattern $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . d . . . . . . . . . . . . . . . | $$ | . . a b . c . . . . . . . . . . . . . | $$ | . . X 0 . . . . . . . . . . . . X . . | $$ | . . . O . 9 . . . . . . . . . . . . . | $$ | . . X O . . . . 2 , . . O . O , X . . | $$ | . . X O O X . 1 W . . . . O X X . . . | $$ | . . X X O 3 . . 7 8 . . . . . . . . . | $$ | . . . . 6 4 5 . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Knotwilg · Post by **Knotwilg** » Fri Jul 24, 2015 1:26 am

Thanks all for the replies. This leaves me with a more general question of direction of play. When I have a 4-4 stone opposing an enemy 3-4 stone (on the same 4th line), should I be tempted to approach that 3-4 stone and as such pincer an approach to my 4-4 stone, to build influence and back up my approach?

Conversely I won't pincer such an approach if the opponent's 3-4 stone is on the 3rd line at my side because my influence will be reduced and I cannot approach the stone. I might pincer high, so that my pincer stone ends up as a reduction of sorts.

Is this proper thinking? Or am I too focused on grabbing the approach move?
Any pro researches available here, on the choice of pincer and the choice of approach?

Uberdude · Post by **Uberdude** » Fri Jul 24, 2015 2:42 am

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

a is the most common answer (1564/2950), b is second (685/2950). Two space low pincer is rare (3 hits) but two space high is third with 215 hits. If white does pincer black will not normally take the corner, because then white ends with sente to approach the 3-4 stone (low better) for a slightly favourable position; so black usually makes a shimari, which makes miai of playing on the right side and taking the corner. As white I prefer to then play at a as it has more fighting spirit to stop black getting the easy opening he wants, and checking the DB this has a higher popularity and win rate (285 of 471 games, 51% win) versus splitting the side (108 of 471 with 40% win).

Btw, With parallel 4-4s I asked On Sojin 7p about playing the one space pincer as white against the approach, and he said it was a little bad (despite many pro games of it), just knight's answer is better. It's ok with the 3-4 to approach (on the lower side) afterwards.

I would not advocate ignoring their approach to approach the 3-4 (but if you do then high please), they will ignore and double approach your 4-4 which is more painful. But if you want to do it for reasons of fighting spirit and stopping them playing their favourite mini-chinese opening then do it, but one space pincer does that too in a more sound way.

Life In 19x19

Two space pincer for efficiency

Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency

Re: Two space pincer for efficiency