Basic Tactics For Breaking Yagura Castle (2)

Continued from the previous article. 

There is another famous tactic with a knight.

Diag.1

In Diag.1, ▲N*24 is the tactic which is often seen in the endgame of Yagura as well as the previous ▲S*41 and ▲S*52. With △Px ▲Px (Diag.2), it seems like sente lost material, but, the pawn on 24 becomes the basis to attack. While sente has a gold or silver in hand, dropping it on 23 next will be a decisive attack for breaking the castle. Thus, in most cases, gote needs to remove it with △Sx in spite of the silver - knight exchange. After this, it proceeds with ▲Rx △P*23 ▲R-28. 

And, sometimes △N*31 is better than △Sx though the point in front of the king remains as the threat. It depends on the situation which to choose. I think, basically, in case of attempting to attack afterward (to gain a tempo), △Sx should be played, and in case of defending thoroughly without giving pieces, △N*31 should be played.
In addition, in reply to ▲N*24, △G-31 and △G32-42 are also considered unless there is subsequent attack.

Diag.2

If gote has a pawn in hand in Diag.2, with △P*23 ▲Px+ △Gx (Diag.3), gote can absorb the basis on 24. However, this defense doesn't always work well because the shape of the Yagura gets worse instead of gaining a knight, especially against the attack from the side. 

Diag.3

For example, In Diag.4, after ▲N*24 △Px ▲Px, dropping △P*23 is a blunder. There is a mate with ▲Px+ △Gx ▲Rx21+ △Kx ▲Rx23+ △P*22 ▲G*32 (Diag.5). The line from ▲Rx21+ is often overlooked. In general, the rook on 1st rank or 2nd rank in the opponent's camp has a big influence to the castle, therefore the player on the defense side needs to be careful about the various tactics to attack.

Diag.4

Diag.5

Then, △N*31 also get into danger with ▲P-23+ △Gx (in case of △Nx, ▲P*24 is severe) ▲Rx31+ △Kx ▲Rx23+ (Diag.6). Promoted the rook near the king, it's hard to protect even if the defense side gains material. 

Here, △Sx ▲Rx △P*23 ▲R-28 is a common line.

Diag.6

When having a knight in hand, the attacker should play with the tactic from ▲N*24 in mind. On the other hand, the defender has to choose the move suitable for the situation, otherwise the castle would be broken immediately.

Basic Tactics For Breaking Yagura Castle (1)

Yagura has been the popular strategy for a long time, regardless of pro and amateur. Especially, beginners tend to prefer it when the double static rook games. In Yagura, a player can form his own camp calmly without caring about detailed things, compared to Bishop Exchange and Side Pawn Picker which have the risk of losing immediately. But, once the attack begins, it goes for a risky game. Both players need to pay more attention to their king's safety in the endgame.

I introduce the basic tactics for breaking a Yagura Castle.

Diag.1

Looking at Diag.1, experienced players imagine ▲S*41 or ▲S*52 for attack. When ▲S*52, if the gold run to 53, sente can take the opponent's bishop with ▲S*41+ (Diag.2). In general, when trying to break a castle, it's better to attack the gold, not the silver, because the gold is stronger than the silver as a defending piece. It can move six squares, and silver is only five.

Diag.2

As for ▲S*41, it depends on the situation whether it works effectively. In Diag.1, after ▲S*41△G-31, in case of ▲S-52+, the bishop can run to the left, and in case of ▲S-52= (unpromoted), the gold can run to 53. There is no subsequent attack. If sente has a pawn in hand, ▲P*43 would be a severe move to take the bishop, though. ▲S*41 doesn't work well singly. But, by cooperating with other pieces, it works well.

Diag.3

For example, in Diag.3, ▲S*41 becomes a good attack. Continuing with △G-31 ▲S-52= △G-53 ▲S-51= (Diag.4), the attack succeeds. The bishop cannot take the silver due to the rook being on 72. The attack with the rook and the silver is often seen in the endgame of Yagura Strategy.

Diag.4

One more example in real pro games.
It's sente's turn at Diag.5. Although there are no attacking pieces for sente, it's possible to launch an attack with hand pieces, a rook, two silvers, and a knight.

Diag.5

Here, ▲S*41 △G-31 ▲S*52 (Diag.6) is a good tactic for breaking the Yagura. In reply to ▲S*52, if the gold run to 53, sente would keep on attacking with ▲N-43 which aims at the gold on 31. Gote's castle become unsafe immediately.

In this way, if you have a silver in hand in Yagura Strategy, it would be good to consider the way to attack with ▲S*41 and ▲S*52 first.

Diag.6

Bishop Exchange Double Reclining Silver

The 3rd game of the Ryuou Title Match started yesterday. Both players formed a same position in Bishop Exchange Strategy.

http://live.shogi.or.jp/ryuou/kifu/27/ryuou201411060101.html

Diag.1

Identical formation at Diag.1 had been in fashion in pro games until about 3 years ago. But, now, the main variation from Diag.1 almost come to the conclusion that sente is winning. Here, sente opens fire with ▲P-45 △Px ▲P-24 △Px ▲P-15 △Px ▲P-75 △Px ▲P-35 (Diag.2). 4, 2, 1, 7, 3 in order. The way to attack with pushing pawns 5 times in a row was discovered by 9-Dan Maruyama, who is one of the top players.

Diag.2

Originally, in Diag.1, sente was supposed to attack with ▲P-45 △Px ▲P-35, but, there was the counter attack with △P-65 (Diag.3). The sequence Maruyama discovered is aiming to remove such an attack from gote. By pushing the pawn on the 7th file in advance, whenever sente gain a pawn, ▲P-74 would occur, then force gote to play defensively. Although at Diag.3, it is not necessarily bad for sente, it is recently considered that pushing pawns 5 times is better than two times.

Diag.3

From Diag.2, △S-44 ▲Rx24 △P*23 ▲R-29 △G-63 (for protecting the knight's head) (Diag.4) used to be a main line, but, now, most pro players hardly play like this because of the conclusion that sente is winning. There are plenty of complicated variations around here, which many players had been researching for decades. I can't write down all of them. In brief, with ▲P*12 △Lx　▲Pｘ34 △B*38 ▲R-39 △B-27+ ▲B*11 △+B-28 ▲Bx44+ △+Bx39 ▲P*22 △Gx ▲S*33 (Diag.5), sente can finally win. This line is called Tomioka Style (8-Dan Tomioka invented). Therefore, in Diag.2, other lines are required for gote instead of △S-44. For example, △Px35 ▲Nx45 △Sx　▲Sx △B*37, and △P-86 ▲Px △P-76 ▲Sx △Rx86, and △R-81 have been played.

Diag.4

Diag.5

Moriuchi selected the line from △P-86 (Diag.6). It was different from Diag.2 in that sente attacked without pushing the pawn on 2nd file, though. The slight difference may have an influence to the position.

Now, the position is in the endgame.

Diag.6