2015年1月22日木曜日

Oushou Title Match

The 2nd game of Oushou Title Match between title holder Watanabe and challenger Gouda started today. It's played as a 7-game match and each game have been played for two days. Today was the first day.

The position has proceeded in Bishop-exchanged Double Reclining Silver. Watanabe for gote selected △P-65 strategy (Diag.1). If anything, this strategy is intended to play defensively, including a draw game due to repetition (thousand-day moves). Then, in some cases, △B*64 is dropped in order to restrict the opponent's attacking formation.

Diag.1


About ten moves later from Diag.1, the position became Diag.2.

Diag.2

From here, it proceeded with ▲R-69 △R-62 ▲R-59 △R-92 (Diag.3)
At a glance, this rook's movement looks strange. But, there is a deep meaning behind ▲R-59 and △R-92.

Diag.3


To put it simply, in Diag.2, sente wants to open fire with ▲P-45 △Px ▲Nx. But, after △S-42, it's not easy to keep attacking. Conversely, gote can take the knight for free with △P*44 next. The attack from ▲P-45 wouldn't go well.
Here, if the gold's position is on 42 in Diag.2, not on 43, the same attack with ▲P-45 △Px ▲Nx would go well because when ▲Nx, the silver must go to 44. In this case, sente is not worried about being taken the knight by △P*44. After △S-44, supporting the knight with ▲P*46 (Diag.4), the position is satisfactory for sente. It's possible to exchange the pawn on the rook's file and manage to keep attacking, such as an edge attack.

Diag.4

Therefore, sente wants to give gote a turn at Diag.2. ▲R-59 was the move aiming at a turn loss purposely. If the rook goes back to 82 instead of △R-92, the aim achieves with ▲R-29. Gote must play something in Diag.2. For example, against △P-74, ▲B*64 △R-92 ▲P-45 △Px ▲Sx would be an effective attack. △R-92 means that when ▲R-29 again, the rook also go back to 82. The position is the same as Diag.2 with sente's turn. It's the repetition. Sente doesn't want to go for a draw game because of first mover advantage.
In Diag.3, although ▲S-47 △R-62 ▲P-56 △B*64 is the common line, challenger Gouda thought the other attack line from ▲P-45 after moving the rook to 48  Today's final position is Diag.5.


Diag.5

If gote takes the pawn, it would proceed with ▲Sx △Sx ▲Nx △S-44 ▲P*46. After this, sente is aiming to drop the bishop on 63. And, △R-82 is also considered in preparation for the attack from 8th file later. In this case, the line of ▲P-44 △Sx ▲R-28 △S-33 is common. Anyway, I think at least both players don't still go for the attack fiercely.






















2015年1月11日日曜日

Side Pawn Picker, △B*45 strategy (1)

I heard from some beginners that when Side Pawn Picker, they are afraid of △B*45 strategy which has the risk of losing immediately, and this is why they hesitate to take a side pawn. After △B*45, it is certain that both players have to attack fiercely without castling. However, △B*45 strategy is rarely seen in pro games because of the high winning percentage for sente. I explain about the basics of this strategy.


Diag.1

Diag.1 is the position which sente just took a side pawn. Here, gote exchanges the bishop with △Bx88+ ▲Sx, and drop a pawn to 28. After ▲Sx, △B*45 is dropped (Diag.2). It's important to throw in △P*28 ▲Sx before △B*45, otherwise when △B*45, with ▲R-24 △P*23 ▲R-28, it won't go well (Diag.3). The rook prevents gote's rook from invading with △Bx67+ ▲Gx △Rx88+. Then, when ▲R-24, the attack quickly with △Bx67+ ▲Gx △Rx88+ is supposed to be better for sente with ▲Rx21+ (Diag.4).

Diag.2


Diag.3
Diag.4

In Diag.4,  sente's threat is king-promoted rook fork with ▲Rx31 △Gx ▲B*33. Thus, gote cannot play like △+Rx89 ▲P*69 △+Rx99 or simply △+Rx99. When ▲P*69, even if gote attacks with △N*55 ▲G-68 △S*67 instead, it won't be an effective attack with ▲G68-58 (Diag.5). There are few attacking pieces. On the other hand, ▲N*24 will be severe for gote later, and ▲B*33 △Gx ▲+Rx31 will also become an effective attack in some cases. In Diag.5, although it seems like sente is in danger, he has an advantage here.


Diag.5

Therefore, gote is supposed to play △B*45 after △P*28 ▲Sx. Then, in this case, when ▲R-24 △P*23, the rook must not pull back to somewhere. With △Bx67+ ▲Gx △Rx88+, gote will be better immediately because compared to Diag.4, sente's rook cannot promote. According to Joseki, against △P*23, ▲B*77 (Diag.6) is the best move.

Diag.6

If the rook on 86 runs to somewhere on 8th file, sente's rook also could run to 26. And, in the position, sente has a strategic advantage because gote doesn't have the attack from △Bx67+ and have already lost two pawns in early stage. For that reason, in Diag.6, it proceeds with △Rx88+ ▲Bx △Px24 ▲Bx11+ (Diag.7).


Diag.7

Diag.7 is the basic position in this strategy. Nowadays, in spite of  silver-lance exchange, it's said that sente is slightly better here. The promoted bishop on 11 has a big influence on the board.