2014年9月27日土曜日

Side Pawn Picker (1)

Side Pawn Picker (Yokofudori in Japanese) is one of the most popular strategies among pro players, but, amateur players don't really prefer it. I suppose this is because Side Pawn Picker tends to be an aerial battle (called like this) which major pieces act dynamically around the middle ranks without advancing generals. It may look complicated.


  1.P-76    2.P-34    3.P-26    4.P-84    5.P-25   6.P-85    7.G-78    8.G-32
  9.P-24   10.Px   11.Rx  12.P-86   13.Px   14.Rx   15.Rx34 (Diag.1)


Diag.1

First of all, gote here must pay attention to sente's threat. If △Rx76 is played as well, with ▲Bx22+, the game will be over immediately.
From Diag.1, gote has several ways to go for strategies.

(1) △N-33 (Diag.2)

Diag.2

△N-33 had been the fashion in the past.
The concept of this move is to bring the king to the right side such as △K-62, △K-72 or △K-62, △S-72, △K-71 (△K-52 is also selectable), and the disadvantage is to stop the bishop's path. Depending on the situation, The knight on 33 will jump to attack. For example, if sente plays ▲R-24 here, △N-45 would occur. ▲K-58 would get into trouble with △Bx88+, ▲Sx, △B*33 (Diag.3). Gote almost win already.


Diag.3


When △N-45, ▲R-25 has been played in pro games. After that, a slashing sequence continues with △Nx57+, ▲Rx22+, △Sx, ▲B*24, △K-52, ▲Bx57, △R*27, ▲P*28, △R-25+ (Diag.3). In spite of gaining a knight, it's still an equal game as the promoted rook has great influence on the board.

Diag.4

If sente wants to avoid this variation, the rook should pull back to 36. ▲R-36 or ▲K-58 is the common move here. And, when ▲R-24, △P-14 is also selectable for gote to go into a slow game.





2014年9月25日木曜日

The 7th game of the Oui Title Match

The Oui Title Match had ended today.
The title holder Habu beat the challenger 8-Dan Kimura, and defended his title with a score of 4-2. There was one draw game.

http://live.shogi.or.jp/oui/kifu/55/oui201409240101.html




In this position, ▲L*83 Habu played was an impressive move.
Sacrificing the lance, and forcing the rook to change the rank, sente is aiming for ending attack.
If gote take this lance, sente would attack like ▲Sx21= △Kx ▲N*24 △S*32 ▲S*12 △K-31▲G*52 (Diag.1). Instead of △S*32, if gote plays △S*23, sente can capture the king with ▲S*12 △Sx ▲G*32 △K-11 ▲P*13 (Diag.2).


Diag.1

Diag.2


Actually, as ▲G*52 is not threatmate, continuing like △B-64 ▲Nx32+ △Kx ▲S*21 △K-31 ▲P*33 △Sx ▲Gx66 (Diag.3), it may be still an equal game. But, gote must pay attention to his king's safety.

Diag.3



Against ▲L*83, the challenger Kimura judged △R-62 as better.
But, Against ▲N*24 at Diag., △S-33 was a losing move because the ending attack from ▲S*12 △K-31 ▲Nx33+ △Gx ▲S*53 occurred. △S*32 was better.
In the postgame, Habu said that he wouldn't have any confidence if △S*32 had been played instead of △S-33.

Watching this series, I felt that Habu's endgame skill was better than Kimura's, and in the top title game, precise calculation is required in endgame.



2014年9月21日日曜日

4th-file rook vs static rook (4)

Continued from Yamada Joseki.

In Diag.1, △P-45 is also possible instead of △P-36.
It used to be written in strategy books that △P-45 was not good because sente's silver could advance to 35 automatically taking a pawn. But, thinking of this position based on modern strategy, I suppose it's still a very close game.

Diag.1

After △P-45 ▲Bx33+ △Sx ▲Sx35 (Diag.2), gote has two ways to counterattack.


Diag.2

(1) △P-34
Continuing with ▲P-24 △Px ▲Sx △Sx ▲Rx, gote here responds △B*33 ▲Rx21+ △R-22 ▲+Rx △Bx (Diag.3) as the variation of △P-36 in Diag.1.
http://kingcrimsondiscipline.blogspot.jp/2014/08/4th-file-rook-vs-static-rook-2.html

Diag.3


Diag.4
Gote is slightly better

Compared with the variation of △P-36 (Diag.4), gote has one pawn less in hand and the place of the pawn on the 3rd file is different. The pawn on 36 is better than on 34 in that the knight on 29 can not jump. Therefore, it seems like gote is not good at Diag.3. But, actually, I think it's by no means easy for sente to win.
▲B*55 △Bx ▲Px △R*28 ▲N-37 △S*49 is the one of the variations from Diag.3, which becomes a close game. ▲S*77 △R*28 ▲N-37 △S*49 is also considered.


(2) △S-44 ▲Sx △Rx  (Diag.5)

Diag.5

△S-44 is the move which was not seen when Yamada Joseki had been the fashion. The similar move appeared afterwards in the variations of Fujii System. If silver run to 34, with △S-35, it's possible to protect the 2nd file.

In Diag.5, sente has several ways to attack. ▲B*55, ▲B*22, ▲R-38 and so on.
After ▲B*55 or ▲B*22, it would proceed with △R-34 ▲Bx11+ △S*39 ▲L*38 △Sx28+ ▲Lx34 (Diag.6). It's an even position. I think gote is easy to win relatively though, because gote's castle is stronger than sente's.
When ▲B*22, the proceeding like △B*33 ▲Bx △Nx ▲R-38 △P*32 is also considered. There are a lot of variations here.


Diag.6
 











2014年9月11日木曜日

Good ending attack

The 6th game of Oui Title Match had ended a while ago.
Challenger 8-Dan Kimura won against the title holder Habu. The ending attack from △N*25 at #99 was great.

http://live.shogi.or.jp/oui/kifu/55/oui201409100101.html


#98

In this position, the gote's threat is △+Rx58, ▲Sx, △G*88, ▲K-97, △Px96.
Sente has to capture the king at this moment without giving a gold. For instance, ▲G-22 here is taken by the rook, and then when ▲+Sx, sente's king is checkmated by △G*88.
Generally, ▲+B-34 would be played here. If taken with the gold, sente would almost win with ▲+Sx. But, with △Nx33, ▲+Bx, △Rx32 (Diag.), gote can gain a gold. The threatmate occurs.




Instead of ▲+Bx, if ▲Gx is played, after △Gx34, ▲Gx, sente's king will be checkmated by △S-88+, ▲Kx, △B*79, ▲K-98, △S*97, ▲Nx, △Bx+, ▲Kx, △+Rx99. ▲N*98, △Px96 (Diag.).



By putting ▲N*25, △Px (△Gx, ▲+Bx, △Px, ▲G*23 mated) before ▲+B-34, it becomes possible to check with ▲+Bx35 when △Nx33 (Diag.). After that, sente can capture the king with △S*24, ▲Gx33.



This is why △N*25 at #99 was a good ending attack.








2014年9月7日日曜日

Ouza Title Match (2)

What both players calculated during the endgame and postgame has been reported in detail on this site.

http://kifulog.shogi.or.jp/ouza/


It is said that △P*66 was losing move for gote at #102 because sente had the decisive attack at that moment.



The position at #101


At first, challenger Toyoshima had been thinking  △P*71 and △G-32 as candidate moves.
But, in the case of △P*71, after calculation with ▲G*53 △N*85 ▲+Rx92 △Lx ▲R-62 △K-23 ▲S*22 △P-25 ▲Px △+Bx ▲P*26 (Diag.1), he couldn't have any confidence in the position.


Diag.1


And, in the case of △G-32, it proceeds to quite complicated positions.
After calculation with ▲N-82+ △Sx68 ▲Gx △G*78 ▲Gx △Sx+ ▲Kx △B*69 ▲K-67 △B-58+ ▲K-66 △+B-46 (Diag.2) ▲S*31 △K-23 ▲N*15 △Px ▲G*22 △K-13 ▲S*14 △+Bx ▲Px15 (Diag.3), he was not sure which side was winning at Diag.3, and then finally evaluated the position as not good for gote. Thus, although he chose △P*66, as the result, △P*66 became a losing move. Habu considered the position as a very close game.


Diag.2

Diag.3

At Diag.2, △+B-46 is a threatmate with △+B58-57 ▲K-65 △+B57-56 ▲G*43. If the king run above like △K-75, the rook will be utilized by △Rx82.
The sequence from ▲S*31 to ▲Px15 is the technique for removing the threatmate and giving a threatmate to the opponent's king reversely. The other ways for gote to deal with the check would lead to a checkmate.
At first glance, you may think sente is winning at Diag.3. But, after this position, a lot of variations still exist. They are written in detail on the website. Please check it out.











2014年9月4日木曜日

Ouza Title Match

The Ouza Title Match between Ouza title holder Habu and challenger 7-Dan Toyoshima started today. Ouza is one of the 7 major titles, and played as a 5-game match.
Both players have 5 hours of thinking time and each game is played within one day different from Oui Title Match.

You can check the game on this site.
http://live.shogi.or.jp/ouza/kifu/62/ouza201409040101.html

Habu had been holding Ouza for 19 years. This is the record for holding the same title continuously. And he has 4 of 7 titles now.


Yagura, Silver-46 Strategy has been played.
You may be surprised that the position is in the endgame already at noon. But, actually, there were several precedents until △S*69. And Habu played a new move with ▲G78-68 against △S*69. I guess he prepared for this move in advance.

It's a complicated game. I'm expecting high level moves will go on from here.









2014年9月3日水曜日

4th-file rook vs. static rook (3)

A continuation from the previous article.
http://kingcrimsondiscipline.blogspot.jp/2014/08/4th-file-rook-vs-static-rook-2.html




 33.B*7g   34.B*5d   35.R-2f   36.L-1b  (Diag.1)


Diag.1


B*5d may look strange at a glance, but it serves as both attack and defense, watching the rook's head indirectly and aiming at a pawn with B*7f. Gote is expecting this bishop to work well. If sente attacks with P-2d against B*5d, it would proceed with Px2d, Sx2d, P-3g+ Sx3g,  P*2g (Diag.2). 
In addition, instead of B*5d, P-6e is also selectable, which attempts to drop B*6d.



Diag.2
Gote is better

The rook cannot take the pawn in Diag.2. P-4f would be a severe move threatening to take the rook with the bishop and promote the pawn with Px4g+ at the same time. Thus, the meaning of R-2f is to avoid the threat beforehand. And, Although Yamada Joseki indicates this line, I suppose it's also possible to take it with the knight when  P-3g+. Continuing with P*2g, Rx2g, P-4f,  Sx3c+, Nx3c, R-2c+, it would be a close game. (Diag.3)



Diag.3

The lance moves up to 1b in preparation for the attack from P-2d. After the silver is exchanged, the bishop on 7f cannot take the lance directly.


37.P-2d   38.Px2d   39.Sx2d   40.Sx2d 41.Rx2d   42.P*2h (Diag.4) 


Diag.4
  
The rook on 2d cannot take the knight in the next because the knight has been strung by the bishop. So, gote doesn't need to guard against Rx2d. Here, P*2h is the counterattack gote has been preparing for since B*5d. 

43.Rx2h   44.P-4f   45.Px4f   46.P-3g+ 47.Sx3g   48.S*2g  (Diag.5)


Diag.5

The sequence from P*2h is one of the characters of Yamada Joseki. 
Sacrificing the pawns with P-4f and P-3g+, the bishop's path is opened clearly to 2nd file. And then it becomes possible to stop the rook's line with S*2g. When P-4f, promoting the rook to 2c is met by Px4g+, Sx4g, P*4f, S-3h, S*4g (Diag.6). Breaking the 4th file, gote is better. 

Instead of S*2g, P*2g is also considered. However, after R-4h, gote has no strong candidates to attack. If gote plays S*3i, it would proceed with S*3i, R-3h, P-2h+, Sx2h, Sx2h+, Rx2h    Rx4f, S*5e (Diag.7). The bishop-rook fork with S*5e gives an advantage to sente.



Diag.6
Gote is better



Diag.7
Sente is better

49.R-4h   50.P*3h   51.R-4i   52.Bx7f  (Diag.8)


Diag.8

Dropping the pawn on 3f instead of P*3h, there would no subsequent attack after the silver run to 2f. On the other hand, sente is aiming at P*2h in the next. So, It's not a good move.
In reply to P*3h, playing with P*2h, it will proceed with P-3i+, P*2g, Bx2g+ (Diag.9). In spite of gaining a silver, gote has a little advantage because the horse and the tokin (promoted pawn) are strong pieces which can take the materials back immediately.
Bx7f may look dangerous as sente would play P*2h, but, gote has the way to help the silver here.


Diag.9


53.P*2h   54.P-3i+  55.Rx3i   56.P*3f 57.Px2g   58.Px3g+  59.Rx3g   60.Rx4f (Diag.10)



Diag.10
equal game

Using the pawn gote just took, the silver exchange is done by P-3i+, Rx3i, P*3f, Px2g, Px3g+, Rx3g.
After the trade, as the silver is not on 3g, the rook can career off to 4g. 
P*4f or S*4f will be played at Diag.10 to prevent the rook from invading. It's still an equal game.

These lines are the mainstream in Yamada Joseki.
If you have any questions, please ask me in the comment field. I will answer as much as possible.