1 to 4 is a fixed sequence. The recent tendency is for White to adopt a high posture with 5---formerly White 'a' was more common. White 5 at 'b' and switching elsewhere are also possible.

White's reason for staking out a high position with 5 in Dia.2 is that he can press at 1 whenever he feels like it. Black2 or Black 'a'-White 'b'-Black 'c' follows, strengthening Black's position, but the sente move of 1 proves to be very helpful for White when playing on the right side. It is also possible for White to begin by playing 1 at 'c'.

White can follow up with 1 when he attaches more importance to the top than to the right side. Black probably has to answer at 2, so White can regard 1 as a forcing move. Black 'a' before White plays 1 is a first-rate point in the fuseki.

White can make a severe invasion at 1 when Black ignores his checking extension. Resisting with 2 is unreasonable because of the combination of 3 and 5. Black's position falls apart after the sequence to 11. The standard answer is to play 2 at 3 and let White connect.

Taking up position with 1 is possible. However, this does not give White the perfect forcing move of Dia. 3, while the exchange of 2 for 3 is Black's privilege. This helps reduce the severity of a white invasion at the top. Black 2 at 'a', aiming at 'b', is also possible.

White 1 to 3 is the direct method for expanding his position on the right. The placement of Black 4 at the vital point is a tesuji. This forces 5, giving Black the chance to fix up his shape with 6. White 7 indirectly defends the cutting point. This sequence is a joseki.

This is the famous 'group-capturing masterpiece' between the top players in the team match between the Nihon Ki-in and the Kiseisha in 1926. It is celebrated as one of the most difficult matches of all time. White built up a large moyo with 1 to 7, whereupon Black invaded at 8 in order to reduce it. The sequence to 19 was forced but Black 20 was questionable. Because of this move White made a ferocious attempt to capture by depriving him of eyes. The fight with the white group in the corner ended up as an approach-move-ko, resulting in a setback for black.

Black could have lived by playing 20 in the Figure at 1. If White still attempts to capture with 2 to 6, Black cuts at 9, then plays the tesuji of 11. The sequence to 17 brings about White's collapse.

Consequently, when Black plays 1, White has no choice but to play 2 to 4, letting Black live with 5, White jumps to 6 and the game will be decided by how well he does in the center.

Black cannot omit the extension to 4, but white can now switch elsewhere. White's shape is very resilient precisely because he played two low moves on the second line. When White does play elsewhere, Black can press at 'a' to build center thickness or play 'b' when he wants to stress the right side.

White has a peaceful answer. Black gets nice shape by blocking at 3 and controls the center, but one must remember White has played two moves fewer here. Next, White can jump to 'a' or switch elsewhere once again.

If Black continues after Dia.11 by blocking at 1, White answers at 2 and can then play elsewhere yet again. Black attacks with 5 and 7, but White lives with the sequence to 12, while creating a cutting point in Black's outside wall. This is not interesting for Black, Black 11 at 12, making this a false eye, is unreasonable as White moves out at 11.

White can answer Black 1 by counterattacking with 2. 3 and 4 make a fight unavoidable. The simple connection at 5 is correct. Up to 12 is forced. The corner lives, so the center becomes the problem area.

This was the first game of Takagawa's successful challenge for the Honinbo Title. The sequence to 12 is a joseki. In this position Black 13 is probably the only move. Even though White invades at 14, Black saves himself with the double contact-play tesuji of 15 and 17. The vulgar cut at 20 instead of 17 is bad, as White captures at 19. Black should play 23 at 24, in exchange for White 'a'. Simply playing 23 lets White make things easy for himself by connecting at 24.

The aim of attacking at 1 is to build up influence on the right side. The idea behind 2 to 5 is the same as in the 5-3 joseki. White 6 is a sparking tesuji. The sequence to 10 has become a joseki.

Black cannot resist White 1 as White has forcing moves at the top. Black 4 is the only answer to 3. White then plays his second tesuji with 5, including 6 and 8 so that he can connect at 9. Moving out with 11 gives him a superior result to Dia. 14.

The hane at 2 is also unreasonable. White uses 3 and 5 as sacrifice stones in order to get out with 7 and 9. Black may have increased his area at the top but his original plan of building up the right side has been shattered. This result is favorable for White.

Answering 4 with 5 is a mistake in direction, as White plays 6 to 10. White's shape seems to be heavy, but settling himself like this means that he is free from anxiety. Black must be sure to play 5 at 8.

Pushing into Black's position with 4 is also an interesting idea. Black will probably extend at 5, so White gets life early by capturing a stone. Once White lives, a black blockading move at 'a' has no effect on him. If Black 5 at 6, White gets a light shape by jumping to 'a'.

White can also answer Black 1 by attaching at 2. However, this move is meant for rescuing oneself in an emergency and is not recommended in an ordinary position. The simple moves of 3 and 5 are good enough for Black. White's overall position up to 6 is too low. Black also has the tough move of 'a' instead of 3.

White tries the knight's move of 3. Suffering Black 4 means a loss in the corner, but White's plan is to get in the extension to 5. White adopts this strategy when Black has an enclosure in the lower right corner. Black's continuation in the corner is Black 'a', White 'b', Black 'c', capturing the two stones.

White plays the combination of 1 and 3 when Black already has the extension at the top. This makes miai of 4 and 5. The result to 5 is equal. If White makes the ordinary move of 'a' instead of 3, pressing at 'b' works well for Black and the extension gains efficiency.