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Monday, November 15, 2010

Shusaku Game 7 - Full Game Review

Alright, this game is so exciting that I had to do the whole thing in one large post. There is a lot of complicated middle game fighting and some interesting joseki sequence including a defunct variation of the taisha joseki. This joseki, known as the 'Great Slant' is famous for being a joseki of several hundred variations. It is as complicated as the 'Avalanche' joseki and even professionals have occasionally made mistakes in playing it out. It is telling of his amazing strength that Shusaku exhibited at an early age that here, playing against a 5 dan opponent, he takes only 2 stones. This is also the first game from 1841, the previous six were from 1840. Shusaku was born in 1829 so he would be turning 12 sometime in the year from which this game record is from. There was no komi as was standard at the time.

Fig. 1
 1-16

A Questionable Invasion - White jumps into the corner right away which gives black a thick position on the outside through 12. Black 10 is played to build influence. The joseki move is for white to play 11 at F2 but 11 is also seen in pro games. Note that the black hane at D6, which is standard in many variations of the corner variation, would be redundant here given the thickness of black's wall. After white takes sente to occupy the lower right corner with 13 black establishes a position in the upper left at 14. This is a great move in terms of how it relates to the wall in the lower left because it extends to the absolute maximum distance possible while still having room to make another move up the side at D17. White plays 15 without hesitation because if black plays here fully 3/4 of the board fall under his influence. Imagine if, instead of 15 white enclosed the lower right corner and black plays at 15. Already you can see that the white invasion in the lower left feels premature. After 15 black plays 16 to initiate the taisha joseki. This joseki has many complicated continuations but in the most severe fighting variations the fight will move down the left side towards black's thick wall so it seems a good choice for black in this position.

Fig. 2
17-25

A Defunct Variation - The moves up through 24 are consistent with the modern joseki but 25 is a mistake. I did some research and this variation is played up through about 1880 and then completely disappears from high level play except for one game I found in 1970. I suspect that there is a specific refutation of this move but it seems that the outside is more important at this juncture. The modern move is to play 25 at F17 after which black can play a variety of moves. I played out several variations from this move and it does seem that black has the advantage in the fighting that ensues after this move. It is possible that simply connecting at F15 would be enough since the white hane at 25 is not as urgent as playing F17. Certainly, however, there are certainly other options and I think pressing at F17 directly also leads to a good result. I think that the sequence played in the game, starting with white 17, is an older joseki because the pattern up to white 27 is common in the 1800s.

Fig. 3 
 26-41

The Taisha! - As you can see the variations of the taisha, as each side seeks to stabilize their two groups, grow quite quickly. The exchange of 26 for 27 was standard at the time of the game which is why I think a move other than 26 might give black some advantage. When black pushes on the outside with 28 white turns at 29 which threatens the corner, forcing black to capture a white stone with 30. Now white has to turn to the stones on the top and connect them to the outside with 31 so black gets to extend on the outside at 32. White takes advantage of black's shape by playing a hane at 33 before jumping out with 35. Black piles on the pressure with 36 and white slips in the atari at 37, forcing black to remove a white stone by capturing at 38. White makes eye shape with 39 (note how 37 is necessary to prevent a black atari at A15, which would ruin white's eye shape) and black follows suit with 40 in the corner. When white jumps out at 41 the action on the left side comes to a halt but black has sente and the black group in the center and the white group on the top are both weak.

Fig. 4
42-57 

Pressing White - Black jumps ahead of white with 42. It is always imperative to get ahead of your opponent in a pushing battle. White thrusts at 43 and then pushes at 45. When white captures at 47 black falls back to 48. Now white jumps ahead of black with 49 and black plays a keima to get in front of white at 50. White makes a two point jump to leap still further ahead of black with 51. This sequence perfectly illustrates the need to get ahead of one's opponent in a pushing battle like this. The down side of the two point jump is that it leaves weakness behind and black takes advantage of this with 52. Through 57 black builds thickness in sente. At this point the game looks very good for black as white has very little secure territory and black's stones dominate the center.

Fig. 5
 58-78

Developing on Both Sides - Black approaches in the lower right and white makes a three space pincer at 59. Black immediately attaches at settles his stones rapidly through 64. The joseki move would be to play at 73 but that would leave the stone at 59 open to a pincer from the star point stone in the upper right. While playing 65 gives white a position on the right side it allows black to attack the lower right corner. The attack at 66 is magnificent. A more orthodox play would be to play at 73 directly but with the outward oriented positions above and to the left a play like 66, inviting white to stoop to the second line for safety, is perfect. It also foresees the eventual turn at 69 and is well placed to contain white to the side. With all of black's influence white cannot make up the difference with 2nd line territory so the goal of this attack is to confine white and make sure that these stones live with little territory. Though white creates some space and threatens to escape to the outside through 77, black 78 puts his eye shape into question and secures a base for the black stones. Black continues to do well in this game, the 4 stone wall from 68-76 is well placed to build territory with the thick formation to the left and the stones in the corner are secure and are well positioned to keep white from connecting 77 to the two space extension on the right. White has sente and must be looking for a way to equalize. Shusaku has played an excellent game so far by emphasizing the center and giving no quarter.

Fig. 6
 79-88

Reducing Black's Influence - White decides that reducing black's influence is of primary importance. To this end white extends out at 79. In and of itself this is a pretty move, turning two fairly weak stones, at C6 and C10, into a nice balanced framework aiming directly at the center area dominated by black. Shusaku apparently understands that using influence to directly make territory is a fools game and instead of protecting his potential territory in the center he makes a powerful hane at 80 which forces white to make an empty triangle at 81. Truthfully white should have played around 80 (playing P7 is one idea since it cramps black's shape) instead of tenuki. Not content black picks another fight on the right side by attaching at 82. White hanes but after the black counter hane at 84 plays tenuki again to peep at 85. This again reduces black's central influence but white is leaving a great many weaknesses in his wake. After 87 black feels that a prudent move to ensure life on the bottom is in order and blocks at 88. This is a good example of honte, or honest play, a solid reinforcement. It is never good to have weaknesses cluttering up the board, restricting future action and since black has a solid position throughout it would be foolish to let white start an attack now.

Fig. 7
89-104

Thrust and Parry - White continues on the right with a cut at 89 and through 93 gets good shape on the side at the cost black capturing a stone in a ladder with 94. This also cuts the original white formation in half. When white cuts at 95 black prudently finishes the ladder with 96. It is almost always a mistake to leave an important ladder hanging, even though 95 wasn't a ladder break if we look just a few moves ahead 99 would be. White plays a tesuji at 97 which makes black's hane at 98 a bit awkward since after white extends at 99 black has to come back and connect at 100. When white plays 1 black must give way again at 2. This gives white the opportunity to capture the cutting stone at O7 in a net by playing at 4 but, instead, white plays an extension at 3 in the upper left. I'm not sure about the logic of this last white move as it doesn't seem very urgent. If black were to play here white could easily live with a modest corner by jumping into the 3-3 point. Whatever the reasons the black extension at 4 is severe.

Fig. 8
 105-127

Chaos! A Complicated Fight - White has few options and 5 is one of the most aggressive. Black has read out the variations and hanes with 6 which is also a very aggressive move. Since black has the advantage in influence it behooves him to attack. The sequence to 13 is forced and then black ataris at 14, forcing white 15, before pushing again at 16. Here white take time to jump to 17, indirectly capturing 14 and threating the five black stones on the right. Black is forced to jump to safety with 18 which gives white time to go back and answer black's push in the center with 19. Black extends again with but white switches back to the right side and cuts with 21. Black noses in with 22 and white blocks with 23. Black activates his other cutting stone by pushing up with 24 and when white extends in the center with 25 black ataris at 26 and white connects with 27. The white position is fairly precarious with the group on the right side having but one eye and four stones floating in the center, although with the cutting point at M11 white still has some aji. I also wonder if you've noticed the weak point at O2? White needs another move to secure eye space on the bottom and it is looking doubtful that white can find the time to defend.

Fig. 9
 128-144

Black extends again in the center with 28 and white saves his right side group by cutting at 29. Through 35 white secures a second eye but loses sente. Black seals the large white group in with 36, this combined with 28 mean that white cannot connect out, as an added bonus 36 makes the black group on the bottom unconditionally alive. White peeps with 37 but black astutely ignores this and goes for bigger fish by making the placement at 38. If black can kill this white group then it won't matter that white follows up with E4 and captures four black stones. With 38 through 44 black ravages white's eye space. I'm somewhat dubious of 39, I would think about playing at 43 or 44 directly after 38. As it stands in the game this white group isn't even assured of a single eye at this point.

Fig. 10
145-165 
59 at 54

White Counterattacks - Starting at 45 white threatens to link up with forces on the outside but black 46 quashes any such ambition. With the game on the line white attempts to capture the black group floating in the center. Through 59 white cuts off the black center but black gets an excellent squeezing tesuji with 54 that allows him to connect at 58 in sente. After white connects at 59 black hanes at 60 which is severe. White keeps pushing with 61 and 63 and then jumps to 65. I like the jump to 65, personally, it seems a stylish move, making the black stone at D11 less relevant, extending from the safe position on the left to the floating group in the center. Still it seems that white is in a precarious position with its large group in the lower right without eyes and the black group in the center in an even dual with another weak white group.

Fig. 11
166-194

A Last Ditch Plan - Black strikes directly by cutting at 66, white defends at 67. Now black jumps to 68 to increase liberties for the upcoming capturing race between his large central group and the large white group in the lower right. White connects underneath with 69 and 71, necessary to continue threatening the large black dragon but after 71 black delivers the deathblow with 72, robbing white of any chance to make eyes or increase liberties. Looking at the board, and probably completely surprised by this young Go playing prodigy, white settles on one last attack. The black stones along the top center have been weakened by the white development in the center during the fighting. If white can capture all these stones then victory would be in reach. To this end white plays 73 to 79 in the upper right to further isolate the black group. Unfortunately black cuts through at 80 and secures life easily through 94 whereupon white resigned.

I hope you enjoyed this game review, I really liked this game and am glad I got to slip another review in before I get swamped by the big run up to finals week in school. Bye everyone.

Thursday, November 11, 2010

Shusaku Game 6 Part 2

Again, I'm in school now so these posts are going to be few and far between, finals are in one month though and then I'll have a bit of free time again. If you're just getting here you might want to start at the first half of the review. And now, the thrilling conclusion to our latest Shusaku game.

Fig 1
 101-129

Remember that black just captured a ko at M15 so white looks to reinforce the stones on top with 1. Black takes the opportunity to seal off the bottom with 2 which, after the forcing move at 3, causes White to invade the corner at 5. Black responds by blocking on the wider side with 6 but then plays a non-joseki move at 8. I did a little research and this is valid when black either highly values the right side or has a lot of supporting stones in the area. In fact it was played by Ishida Akira 9p as white against Takemiya Masaki 9p in the 1995 Tengen tournament in Japan and white went on to win by 2.5 points, you can review the game on Eidogo if you want. It also is hard for white to live in sente against black 8. Notice that after 9 and 11 black could have ignored these to jump in at B2 and do great harm to the potential for White to make eyes locally. If the 3 black stones at C8 were stronger this might have been a viable strategy. After white descends at 13 black turns to the weak group at the top and looks to take profit while destroying White's eye space. Unfortunately white moves out smartly and while black does take a large corner there is still a sense of the stones on the top, both the top center and the upper right corner, being over concentrated. Finally white connects at 29 to secure access to the center.

Fig. 2
130-151

Black strikes at the white group on the bottom with 30 before turning back to lash out at white's group which is safe enough to let white play 33 before connecting to the right through 39. Now black turns to the center with 40 and after building a little thickness with 41 and 43 before jumping into black's territory with 45. Adding in the hane at 47 and at 51 it seems that white has pulled fairly close to even on the board. Certainly black has not gotten much territory in the lower left after building such a large framework earlier in the game. I think white has done well at seizing the initiative so far.

Fig. 3
 52-79

Most of these moves are pretty clear, black defends his territory on the bottom with 52 and white creates some aji with 53. Black plays a series of sente sequences starting with 56 and 58 on the right and then playing the large hane at 60 on the left. After forcing a bit more through 66 black turns to the bottom to make a capture with 68 and 70. Now white plays at 71 to prevent black from taking the corner and notice how 76 and 78 work to create a shortage of liberties in the corner for white. White can''t block at T2 with 79 because he would put himself in atari. This is a nifty sequence that eats away at white's territory on the bottom. After 78 white turns back to block at 79 which is necessary to prevent the ko that black could create by playing at 79 (white pays O1 and black can create a false eye by playing at P3).

Fig. 4
 80-210

Black secures his territory on the bottom with 80 and white responds by cutting through the center with 81. A small fight starts and with 88 and 90 black decides to expand the bottom rather than try to salvage some territory in the central area. White makes time to make the large hane at the top with 91. Black turns to the lower left with an atari at 92 to which white defends with 93 forcing black to connect at 94. Taking sente white builds a bamboo joint in the center with 95 and proceeds to force black through to 203 (3 on the diagram) before turning to defend the lower left at 5. Black makes the sente endgame hane at 6 and because of the bad aji in his shape white has to make eyeshape at 9 which lets black turn at 10 in the lower right. The game is very close at this point and only small endgame moves remain.

Fig. 5
211-245

The final push for both sides is here. This takes us through to the end of the game record and while there are still a few moves to be made around H18 the game is almost over at this point. The record indicates that white won by a single point which gives him revenge on Shusaku for their last game which went the other way by the same minuscule margin. Thanks for reading and I hope you enjoyed the game.