From: Manabu Terao <Manabu.Terao <at> JAPAN <dot> SUN <dot> COM>
Date: 12 feb 1999
Subject: Shogi strength drill - #15

Dear Shogi Fans,

Here is Problem #15.

Manabu Terao(on behalf of ISPS)


Problem #15

One of weak points of Katayagura is the ears('kobin') of the King. It's
critical for you to make use of your opponent's weakness. Where would
you drop your kNight in hand as the vital move?

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

Answer #15

   9    8    7    6    5    4    3    2    1
+--------------------------------------------+       White in hand:
|    |    |    | bR |    |    |    | wN | wL |  a   +------------------+
+--------------------------------------------+      | (Rest pieces)    |
|    |    |    |    |    | wG | wK |    |    |  b   |                  |
+--------------------------------------------+      +------------------+
|    |    |    |    | wP | wG |    | wP | wP |  c
+--------------------------------------------|
|    |    |    |    |    | wP | wP | bP |    |  d
+--------------------------------------------+
|    |    |    |    | bP |    |    |    | bP |  e
+--------------------------------------------+
|    |    |    |    |    |    | bP | bR |    |  f
+--------------------------------------------+
|    |    |    |    |    |    | bN |    |    |  g
+--------------------------------------------+      Black in hand:
|    |    |    |    |    |    |    |    |    |  h   +------------------+
+--------------------------------------------+      |SS                |
|    |    |    |    |    |    |    |    | bL |  i   |                  |
+--------------------------------------------+      +------------------+

The answer is ; N*2d, Sx2d, Px2d

Point : kNight drop at 2d to ruin the Katayagura

S*5a would be much worse. This Silver drop would make little
effect on White's castle.

P2d can be considered. This is a light tesuji move aiming at
whether S*2c or N*2c to be followed by Kx2c, Rx2a+ if White
captures it by Px2d. But it's not severe enough.

You will see what a fine move Nx2d is! If White respond it by
Px2d, there will be a mate as following sequence;

      Nx2d, Px2d, S*2c, Kx2c, Rx2a+, (any piece in hand)*2b,
      Px2d, Sx2d, Rx2d, Kx2d, +Rx2b, (any piece in hand)*2c,
      S*2e,

altough this sequence may not be easy enough for beginners
to read through. Then White has no choice but capturing the
kNight drop on 2d by Sx2d and it will be no problem if you
capture back the silver by Px2d. If White respond it by Px2d,
there will be the same mate sequence as above and the solid
Katayagura castle will become broken instantly.

Please remember N*2d to use it in your real games.