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.