As we have seen in the previous weeks, Black has a variety of options in response to White 6. The most popular moves were defending at A and pincering at or near B. A move that was sometimes seen in pro games was C. However, some of my students have asked me if it is possible to defend the corner. Although the game is ultimately about territory, the sanrensei opening stresses influence, as illustrated by the moves on the fourth line. If you want to defend the corner, locally the best move would probably be 7. This move has been played in pro games, but only when the circumstances were right. And, as you might have guessed by now, they differ from this diagram.

 

Last week we looked at a game by Takemiya Masaki, and this week we will look at another of his games. For the amateur who studies thickness and influence in general and the sanrensei specifically, Takemiya is a good top pro to imitate. In this game, played in 1982, his opponent is hane Yasumasa, 9-dan. Before answering White 6, Black decides to play a yosumiru move. Although the sequence in the top left is joseki, locally White gets a better result, even taking in account that White spends an extra move. However, Black is probably happy because his thickness in the top left works together with his sanrensei. Whether Black 23 is the best move is unclear, but it is certainly ambitious. Let’s see what happened in the game.

 

White is now forced to make an extension somewhere along the top, allowing Black to approach at 25 and make a base up to 29. White 30 is a large move, but so is Black 31. As an added bonus White builds thickness in sente with 32 and 34. However, Black is not unhappy to be forced to play a huge endgame at 35—a White move would be sente. White is now ready to invade in the lower right. As we stated last week, when Black has a double-wing formation (extensions on each side from the star point in the lower right), White should usually invade at the 3-3 point, as White does with 36. Black must block on the wider side, which is 37. The moves through 47 are a joseki. Now you can see that the stone at A has its limitations: it does not protect the right side. When White invades at 48, Black has to add a stone at 49, giving a slightly cramped position. White attached at 50, which started a long battle. In the end, Black won by 1.5 points.

 

The last move we will look at in response to a kakari at A is Black 1. In conjunction with the sanrensei, this is a very special move, and the circumstances in which Black played this move were quite different. As a matter of fact, the left side featured a rare position. Let’s investigate.

 

In this game, played in 1975, the players are Sekiyama Toshio (Black) and Hashimoto Shoji, both 9-dan. The sanrensei appeared unexpectedly, after Black had captured a stone in the top left. To optimize his chances of using this influence, Black choose to develop the right side. The top appears to be the largest place to make territory for Black, so White approaches with 18. In this particular case, Black 19 seems a fine move. Why? Black wants White to extend along the top, because that is a relatively uninteresting area. There are two reasons for this. First, for Black it is difficult to turn the top into territory because it is open around A. Second, a White extension from 18 to the left has no impact on Black’s strength. His ponnuki (plus 9) is extremely strong. You might then argue, ‘If the top is not interesting for Black, why should White play here then?’ That is a good point. Imagine the position without the 18/19 exchange but with a Black move at B or C. Can you see that this Black moyo could take on gigantic proportions?

 

White has little choice but to extend to 20—this move definitely has to be on the fourth line because this game is not about territory but about influence, especially at the top. Also, playing on the fourth line makes this stone light, meaning it can escape easily. Meanwhile, Black’s stones marked with triangles stand as a rock and they will never come under attack. But that is not the meaning of White 20. He plays a light move here to prepare for an invasion at C or D. It is unclear what the impact is of the exchange A for B, but Black’s position is that he has defended the corner and he is daring White to invade the right side.

The moves 21 through 35 are given as a reference. The idea behind White’s tight moves of 32 and 34 is that he makes a strong position here. Once he is strong, he is confident he can fight his way out with his weaker stoner in the lower left. After Black 35, the game turns into a confused free-for-all fight.