Re: [eboard-devel] Eboard "allows" illegal moves when playing against GNUchess 5

[Felipe B. <be...@se...>]

On Wed, 16 May 2001, Daniel Burrows wrote:

The official answer here is: GNU Chess 5 sucks.
When the engine reports that the move was illegal, eboard accepts the
report and goes back, but GNU Chess 5 simply ignores the bad moves without
any answer, as if it was a no-op.

When I first added engine support, eboard's internal move checking code
(in the position.cc file) was too bare and I was afraid if I disallowed
'illegal moves', the incompleteness of the code could block legal moves. I
should add soon an option in the Settings menu to check legality (it must
be a user toggle, not always be on, or variants like wild can become
unplayable). The code is much better now, I think I can already add this
option.

But GNU Chess 5 is failing to give a 'illegal move' string when it
receives a bad move, as stated in the xboard protocol draft. If you want
to go away with it, I suggest sending a bug report to the GNU Chess 5
author. IMHO, GNU Chess 5 sucks so much that it's easier to rewrite it
from scratch.

GNU Chess 4.0pl80, Sjeng 9.1 and 9.2, and Crafty 18.9 report correctly the
illegal move. (I did notice some weird responses from Crafty yesterday
concerning move acceptance, but logging was off and I couldn't reproduce
it anymore -- but somehow it was failing to accept legal moves in
mid-game)

>   Just a quick bugreport to start the day:
>
>   When playing against GNUchess 5, I can click on a piece and make a wildly
> illegal move with it; eboard will accept the move and show the piece in
> the new position, but the engine (unsurprisingly) goes and sulks in the corner,
> or at least doesn't make any additional moves.  (it doesn't print any error
> messages either)
>
>   The simplest thing to do is to start a game against GNUchess (playing as
> black), select your King-pawn, and move it to g4.  (many other bad moves
> are possible, such as Nxh1)
>
>   I don't know if this affects other play modes; I haven't checked.
>
>   Daniel
>

.........................................................................
Felipe Paulo Guazzi Bergo - Free Software Developer (be...@se...)
Personal Info and GPG Public Key: http://www.advogato.org/person/khazad
Campinas - SP - Brazil - Earth

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