Computer Chess Club Archives


Search

Terms

Messages

Subject: Crafty and draw by repetition ?!

Author: pete

Date: 13:32:21 04/21/00


Game : Crafty17.10 (winboard)- Junior6 on 2 computers ( rest really irrelevant
); crafty played with the "official" book.bin .

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Be7 6.Re1 b5 7.Bb3 d6 8.c3 0-0 9.h3
Bb7 10.d4 Re8 11.Ng5 Rf8 12.Nf3 Re8 13.Ng5 Rf8 14.Nf3

Here crafty claimed draw by repetition !?

Part of crafty-logfile :

Black(13): time 462484
time remaining:  77:04 (crafty).
Black(13): otim 447395
time remaining:  74:33 (opponent).
Black(13): e8f8
predicted move made.
              time=5:41  cpu=99%  mat=0  n=67749325  fh=90%  nps=198567
              ext-> checks=777869 recaps=260250 pawns=28570 1rep=59721 thrt:1500
              predicted=14  nodes=67749325  evals=22514617
              endgame tablebase-> probes done=0  successful=0
              time used:   1:38
White(14): Nf3
              time used:   4:03
game is a draw by repetition.
1/2-1/2 {Drawn by 3-fold repetition}

       +---+---+---+---+---+---+---+---+
    8  | *R|   |   | *Q|   | *R| *K|   |
       +---+---+---+---+---+---+---+---+
    7  |   | *B| *P|   | *B| *P| *P| *P|
       +---+---+---+---+---+---+---+---+
    6  | *P|   | *N| *P|   | *N|   |   |
       +---+---+---+---+---+---+---+---+
    5  |   | *P|   |   | *P|   |   |   |
       +---+---+---+---+---+---+---+---+
    4  |   |   |   | P | P |   |   |   |
       +---+---+---+---+---+---+---+---+
    3  |   | B | P |   |   | N |   | P |
       +---+---+---+---+---+---+---+---+
    2  | P | P |   |   |   | P | P |   |
       +---+---+---+---+---+---+---+---+
    1  | R | N | B | Q | R |   | K |   |
       +---+---+---+---+---+---+---+---+
         a   b   c   d   e   f   g   h

              puzzling over a move to ponder.
              clearing hash tables
         nss  depth   time  score   variation (1)
                6->   0.83   0.00   14. ... Re8
                7     0.83   0.00   14. ... Re8
Black(14): Re8 [pondering]
              clearing hash tables
              time limit 2:42 (16:15)
         nss  depth   time  score   variation (1)
Black(14): result 1/2-1/2 {Drawn by 3-fold repetition}
Black(14): force
Black(14): quit
LearnBook() executed
execution complete.

This seems to be a bug to me . As far as I understand the rule the 1st one who
could claim draw here is black when he plans Re8 which is btw not forced at all
.

Minor issue is that I have seen this special opening line in a few computer
programs opening books now and I remember a few that won't avoid the draw by
simply choosing something else .

happy easter.

pete








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.