Diagram 1 The SWOT analysis of this position is as follows:|
- The upper side is very strong, but the “b” stones don’t reach out very far into the vital center, so their overall impact is only modest.
- The “k” stones already have one eye and potential for another both on the edge and in the center, so they may be considered modestly strong.
- The “i” stones have no eyes and are pressed on both sides by Whites which are stronger.
- The (modest) chance to exploit the weakness of the White “h” stones.
- The (even more modest) possibility of rescuing the trapped “e” stone.
- The chance to attack and possibly capture the White “f” stone.
- The potential for attacking the White “j” stones which still have only 1 eye.
- The still unsettled status of the fairly large “k” group.
- The weakness of the “i” group, sandwiched between the stronger White “h” and “j” groups.
- 10+ points in the upper left corner.
Figure 1 The SWOT analysis of this position is as follows:
- A still quite incomplete lower left corner enclosure.
- Good shape in the upper left corner that should allow making two eyes against any currently foreseeable attack.
- A fairly thick and almost connected right side, with one almost abandoned embedded White stone (W14) and one weak White stone (W26), both within Black’s Sector Lines.
- The “thin”Black lower left side position.
- The chance to exploit the weakness of W6 on the left, and W14 and W26 on the right.
- The possibility for invasion into the big gap between W12 and 24 on the upper side.
- The Aji of the gap between W18 and 24.
- The potential for expansion from the lower left corner, especially along the lower side.
- The potential inherent in White’s possible development of W6 on the left and W14 and 26 on the right.
Figure 2 W32 induced B33 to defend the corner territory, and then W34 not only made a base but threatened to more or less
complete a large moyo on the lower side by continuing at “a” or thereabouts at an appropriate later time.
When B35 strengthened Black’s upper border, it would normally induce W“b” in response to preclude Black’s strong pressing move there. But in this situation the threat it posed against W14 and 26 on the right side is far more serious, so White felt compelled to respond to that instead!
W36 follows the maxim of attaching for defense (see Chapter 1), and after the natural Hane of B37 in response, the cross cut of W38 is a standard technique to “make shape”.
But after the atari of B39, W40, B41, instead of playing W42 White might have been better advised to simply play W“c”, B45, and then skip out lightly (and relatively safely) into the center with W“d”. But because White was also looking at the weakness of the Black lower right side group ...
The sequence shown followed through W52, after which Black has succeeded in the first stage of his strategy by inducing White to develop the weak and isolated W26 into a group too large to give up, but which is nevertheless still ripe for attack!
Figure 3 After W52 White was out of Black’s Sector Lines, so there was no good way for Black to immediately exploit that still unsettled White center group. So Black’s
attention shifted to White’s threat to close off a big lower side moyo, and for this purpose the invasion of B53 was an excellent way to start!
In this situation, the instinct of the typical beginner/intermediate would be to immediately aim next at the potentially vulnerable W32-34 two point third line skip in the lower left, but Black’s sophisticated plan is much deeper than that!
Black’s clever idea is to use B53 et seq as a diversionary mechanism for creating thickness in that area, with which to then:
- support any weaknesses in his own lower right side group, and
- prevent a later flight to safety in that direction by the weak White center group!
After accomplishing those objectives, Black also emerged with Sente because W78 was necessary to secure White’s eyespace and territory in the lower right corner. So Black was free to implement his plan with the cap of B79, blocking the flight of the now large and still eyeless right center White string, once again enclosing it in Black Sector Lines, and forcing it to seek safety above.