Computer Chess Club Archives


Search

Terms

Messages

Subject: K+P ending in practical play

Author: Bruce Moreland

Date: 09:43:26 10/26/98


Here is the tail end of a game played between my program (Ferret) on a 533 mhz
Alpha and Crafty on a dual 450 mhz Pentium II, at time control of 5 0, on ICC.

My program got smoked in a K+P ending it traded into (apparently) voluntarily.

One of the things you hear about if you talk to old-timers in this field is that
the square of the pawn is a totally important evaluation term.  I'm not sure who
said it, but someone said that it's worth 100 Elo points.  This was a long time
ago, back when programs would get killed in endings routinely, but I get the
idea that this wisdom hasn't been re-evaluated much since then.  It is my
opinion that square of the pawn is worth almost nothing in practical play, since
the number of K+P endings that actually occur, with play still in them, seems to
be approximately zero.

This ending may prove to be a counter-example.  I currently don't have this
knowledge in my program.  I'm going to stick it back in and see if it
understands this ending better.

I would be interested in knowing if anyone has any thoughts about this subject
in general or this ending in particular.

[White "Ferret"]
[Black "Box"]
[Result "0-1"]
[ECO "C75"]
[WhiteElo "2986"]
[BlackElo "2969"]
[Opening "Ruy Lopez: modern Steinitz defense"]
[NIC "RL.11"]
[Time "19:46:56"]
[TimeControl "300+0"]
[SetUp "1"]
[FEN "8/6pp/4pk2/4p3/2PqP3/3Q2P1/4KP2/8 w - - 18 62"]

62. Qxd4 exd4 63. f4 e5 64. c5 exf4 65. gxf4 h5 66. e5+ Ke6 67. Kd3 h4 68. c6
g6 69. c7 Kd7 70. Kxd4 h3 71. Ke3 h2 {White resigns} 0-1

--------------------------------

    a   b   c   d   e   f   g   h
  +---+---+---+---+---+---+---+---+
8 |   |///|   |///|   |///|   |///| 8
  +---+---+---+---+---+---+---+---+
7 |///|   |///|   |///|   |/p/| p | 7
  +---+---+---+---+---+---+---+---+
6 |   |///|   |///| p |/k/|   |///| 6
  +---+---+---+---+---+---+---+---+
5 |///|   |///|   |/p/|   |///|   | 5
  +---+---+---+---+---+---+---+---+
4 |   |///| P |/q/| P |///|   |///| 4
  +---+---+---+---+---+---+---+---+
3 |///|   |///| Q |///|   |/P/|   | 3
  +---+---+---+---+---+---+---+---+
2 |   |///|   |///| K |/P/|   |///| 2
  +---+---+---+---+---+---+---+---+
1 |///|   |///|   |///|   |///|   | 1
  +---+---+---+---+---+---+---+---+
    a   b   c   d   e   f   g   h

8/6pp/4pk2/4p3/2PqP3/3Q2P1/4KP2/8 w - - 18 62

White to move and lose.  My program played 62. Qxd4, with a score of about +1,
although the move apparently loses by force.  I would be interested to know if
other programs avoid 62. Qxd4.  If white can safely avoid this move it should be
better, I think.

--------------------------------

    a   b   c   d   e   f   g   h
  +---+---+---+---+---+---+---+---+
8 |   |///|   |///|   |///|   |///| 8
  +---+---+---+---+---+---+---+---+
7 |///|   |///|   |///|   |/p/| p | 7
  +---+---+---+---+---+---+---+---+
6 |   |///|   |///| p |/k/|   |///| 6
  +---+---+---+---+---+---+---+---+
5 |///|   |///|   |///|   |///|   | 5
  +---+---+---+---+---+---+---+---+
4 |   |///| P |/p/| P |///|   |///| 4
  +---+---+---+---+---+---+---+---+
3 |///|   |///|   |///|   |/P/|   | 3
  +---+---+---+---+---+---+---+---+
2 |   |///|   |///| K |/P/|   |///| 2
  +---+---+---+---+---+---+---+---+
1 |///|   |///|   |///|   |///|   | 1
  +---+---+---+---+---+---+---+---+
    a   b   c   d   e   f   g   h

8/6pp/4pk2/8/2PpP3/6P1/4KP2/8 w - - 0 63

White to move.  Here is the positions with the queens off, if this helps anyone.
 I think white is lost already here.

--------------------------------

    a   b   c   d   e   f   g   h
  +---+---+---+---+---+---+---+---+
8 |   |///|   |///|   |///|   |///| 8
  +---+---+---+---+---+---+---+---+
7 |///|   |///|   |///|   |/p/|   | 7
  +---+---+---+---+---+---+---+---+
6 |   |///|   |///|   |/k/|   |///| 6
  +---+---+---+---+---+---+---+---+
5 |///|   |/P/|   |///|   |///| p | 5
  +---+---+---+---+---+---+---+---+
4 |   |///|   |/p/| P |/P/|   |///| 4
  +---+---+---+---+---+---+---+---+
3 |///|   |///|   |///|   |///|   | 3
  +---+---+---+---+---+---+---+---+
2 |   |///|   |///| K |///|   |///| 2
  +---+---+---+---+---+---+---+---+
1 |///|   |///|   |///|   |///|   | 1
  +---+---+---+---+---+---+---+---+
    a   b   c   d   e   f   g   h

8/6p1/5k2/2P4p/3pPP2/8/4K3/8 w - - 0 66

White to move is completely lost.  Mine figures this out after a while, but it
takes too long, in my opinion (over a minute on a P6/200 to really start to
crater).  I'd be interested in knowing if anyone knows they are dead quickly.

Thanks,

bruce



This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.