From: Manabu Terao <Manabu.Terao <at> JAPAN <dot> SUN <dot> COM>
Date: 19 feb 1999
Subject: Shogi strength drill - #16

Dear Shogi Fans,

Here is Problem #16.

Manabu Terao(on behalf of ISPS)


Problem #16

Yagura Castle will be ruined instantly if you attack the vital point.
It will be the most effective to sacrifice your kNight in hand to do
so.


   9    8    7    6    5    4    3    2    1
+--------------------------------------------+       White in hand:
|    |    |    |    |    |+bB |    | wN | wL |  a   +------------------+
+--------------------------------------------+      | (Nothing)        |
|    |    |    |    |    |    | wG | wK |    |  b   |                  |
+--------------------------------------------+      +------------------+
|    |    |    |    |    | wG | wS | wP | wP |  c
+--------------------------------------------|
|    |    |    |    |    | wP | wP |    |    |  d
+--------------------------------------------+
|    |    |    |    |    |    |    | bP | bP |  e
+--------------------------------------------+
|    |    |    |    |    |    | bP | bR |    |  f
+--------------------------------------------+
|    |    |    |    |    |    | bN |    |    |  g
+--------------------------------------------+      Black in hand:
|    |    |    |    |    |    |    |    |    |  h   +------------------+
+--------------------------------------------+      | SN               |
|    |    |    |    |    |    |    |    | bL |  i   |                  |
+--------------------------------------------+      +------------------+

Reference #16

   9    8    7    6    5    4    3    2    1
+--------------------------------------------+       White in hand:
|    |    |    |    |    |    |    | wN | wK |  a   +------------------+
+--------------------------------------------+      |SP                |
|    |    |    |    |    |    |+bB |    |    |  b   |                  |
+--------------------------------------------+      +------------------+
|    |    |    |    |    | wG | wS | wP |    |  c
+--------------------------------------------|
|    |    |    |    |    | wP | wP |    | wL |  d
+--------------------------------------------+
|    |    |    |    |    |    |    | bP |    |  e
+--------------------------------------------+
|    |    |    |    |    |    | bP | bR |    |  f
+--------------------------------------------+
|    |    |    |    |    |    | bN |    |    |  g
+--------------------------------------------+      Black in hand:
|    |    |    |    |    |    |    |    |    |  h   +------------------+
+--------------------------------------------+      |GN                |
|    |    |    |    |    |    |    |    |    |  i   |                  |
+--------------------------------------------+      +------------------+

The answer is ; N*2d,Px2d,Px2d.

Point : kNight drop at 2d as a tesuji of breaking Yagura Castle.

N*5e will be worse. White will respond it by G4c-4b to threat
your promoted Bishop and you will lose initiative as you are
most likely to prevent your promoted Bishop from being taken.

P1d can be considered a good move if you plan the following sequence;
P1d, Px1d, Lx1d, Lx1d, S1a, Kx1a, +Bx3b(See Reference diagram above)
It is a fine sequence. But there will be a sharper sequence.

   (Text to be continued below the Answer Diagram)

Answer #16

   9    8    7    6    5    4    3    2    1
+--------------------------------------------+       White in hand:
|    |    |    |    |    |+bB |    | wN | wL |  a   +------------------+
+--------------------------------------------+      | N                |
|    |    |    |    |    |    | wG | wK |    |  b   |                  |
+--------------------------------------------+      +------------------+
|    |    |    |    |    | wG | wS |    | wP |  c
+--------------------------------------------|
|    |    |    |    |    | wP | wP | bP |    |  d
+--------------------------------------------+
|    |    |    |    |    |    |    |    | bP |  e
+--------------------------------------------+
|    |    |    |    |    |    | bP | bR |    |  f
+--------------------------------------------+
|    |    |    |    |    |    | bN |    |    |  g
+--------------------------------------------+      Black in hand:
|    |    |    |    |    |    |    |    |    |  h   +------------------+
+--------------------------------------------+      | SP               |
|    |    |    |    |    |    |    |    | bL |  i   |                  |
+--------------------------------------------+      +------------------+

                   ( Continued )

N*2d is a fine move. If White respond it by moving G3b-4b, your S*3a will
close the game. If White respond the N*2d by moving G4c-4b, then there
will be brinkmate(Hisshi) followed by Nx3b+,Gx3b,G*4c,Gx4c,S*3b.

Therefore, White has no choice but to capture your N*2d by Px2d. and then
it will be no problem for you to capture back the pawn by Px2d.

After your Px2d, White will be forced to capture the pawn by Sx2d.
Then your P*2c will lead two brinkmate(Hisshi) sequences.
One is ; Gx2c,S*3b. The other is ; Kx2c,Rx2d,Kx2d,+Bx3b, White
cannot avoid your two Gold drops at 2c or 2e to mate at the same
time. In case you cannot let your Rook in White's hand, then take
the following sequence; Sx2d,Rx2d,Px2c,R2h, aiming next S*3a.

To make a long story short, N*2d is the vital point and the quickest
approach to White King in Yagura Castle.