Legal moves deemed illegal by the Cute Chess GUI

[Gabor Szots]

Two games from a PGN played under the Cute Chess GUI. The GUI terminates both games because of alleged illegal moves by Alibaba. However, no ilegal moves were made. Have you seen such a behaviour by Cute Chess yet? What can be the reason?

[pgn][Event "My Tournament"]
[Site "?"]
[Date "2022.09.10"]
[Round "1"]
[White "Alibaba_1.38-x64-SzG"]
[Black "Trinket_2.0.0-x64"]
[Result "0-1"]
[ECO "C49"]
[GameDuration "00:00:01"]
[GameEndTime "2022-09-10T08:29:37.870 Közép-európai nyári idő "]
[GameStartTime "2022-09-10T08:29:36.309 Közép-európai nyári idő "]
[Opening "Four knights"]
[PlyCount "14"]
[Termination "illegal move"]
[TimeControl "30+0.2"]
[Variation "Symmetrical Variation"]

1. e4 {book} e5 {book} 2. Nf3 {book} Nc6 {book} 3. Nc3 {book} Nf6 {book}
4. Bb5 {book} Bb4 {book} 5. O-O {book} O-O {book} 6. d3 {book} d6 {book}
7. Bg5 {book} Bg4 {-0.14/6 1.3s, White makes an illegal move: Rf1-e1} 0-1
[/pgn]

[pgn][Event "My Tournament"]
[Site "?"]
[Date "2022.09.10"]
[Round "1"]
[White "Trinket_2.0.0-x64"]
[Black "Alibaba_1.38-x64-SzG"]
[Result "1-0"]
[ECO "A56"]
[GameDuration "00:00:02"]
[GameEndTime "2022-09-10T08:29:41.872 Közép-európai nyári idő "]
[GameStartTime "2022-09-10T08:29:38.889 Közép-európai nyári idő "]
[Opening "Czech Benoni defense"]
[PlyCount "13"]
[Termination "illegal move"]
[TimeControl "30+0.2"]

1. d4 {book} Nf6 {book} 2. c4 {book} c5 {book} 3. d5 {book} e5 {book}
4. Nc3 {book} d6 {book} 5. e4 {book} Be7 {book} 6. Nf3 {+0.24/6 0.79s}
O-O {-0.09/6 0.25s} 7. Be2 {+0.25/6 1.7s, Black makes an illegal move: Bc8-g4}
1-0
[/pgn]

[Lazy_Frank]

I have seen illegal moves if cute-chess cli chess variant (there is a lot) do not match the actual game chess variant.
Could be one of reasons.

[hgm]

It is a bit suspect that this seems to occur always with the same engine. It would be interesting to see what the engine printed as bestmove. Perhaps there is a spurious promotion indicator on the move.

[Guenther]

Two games from a PGN played under the Cute Chess GUI. The GUI terminates both games because of alleged illegal moves by Alibaba. However, no ilegal moves were made. Have you seen such a behaviour by Cute Chess yet? What can be the reason?

White makes an illegal move: Rf1-e1
Black makes an illegal move: Bc8-g4

Well, the move format in Alibaba is strictly said wrong! (WB does some pampering and accepts it despite of it)
If you check my XB/UCI chronology details page! you'll find this entry for Alibaba:

Code: Select all

Name            Vers. FR (prev. name)   Vers. LR        YM-LR   RC      Src     PL      Prot    "CMD (arg) Config"      Peculiarities + Bugs    Author L.N.
Alibaba         1.0 JA                  1.40 JA         2012-11 C3      yes     C       XB      "(-h-256) alibaba.ini"  move format Xe2-e4      Breuker/Ablett

(the dash in move format is against the strict specs)

Running it via WB2UCI fixes it e.g. w/o changing the source.
example:

Code: Select all

[ENGINE]
Name=alibaba_140JA
Author=Denis Breuker (Jim Ablett)
Filename=alibaba_140JA.exe

[OPTIONS]
Program=alibaba140JA.exe
Logfile=true
Protocol=1

Here a snippet from a log showing what it acchieves:
(last two lines show the transformation of the move format from a wrong xboard move output to a correct uci move otput)

Code: Select all

4.383: C> setoption name UCI_Opponent value none none computer Storm_06
4.383: C> position startpos
4.383: C> position startpos moves e2e4
4.383: C> position startpos moves e2e4 e7e5
4.383: C> position startpos moves e2e4 e7e5 g1f3
4.383: C> position startpos moves e2e4 e7e5 g1f3 b8c6
4.383: C> position startpos moves e2e4 e7e5 g1f3 b8c6 c2c3
4.383: C> position startpos moves e2e4 e7e5 g1f3 b8c6 c2c3 g8f6
6.833: C> position startpos moves e2e4 e7e5 g1f3 b8c6 c2c3 g8f6 f1b5
6.833: C> isready
6.833: C< readyok
6.833: C> go wtime 117552 btime 120000 movestogo 37
6.833: C< info depth 1 score cp 1
6.833: S< new
6.833: S< post
6.833: S< hard
easy
6.833: S< name Storm_06
6.833: S< computer
6.833: S< level 40 2 0
6.833: S< force
6.833: S< e2e4
6.833: S< e7e5
6.833: S< g1f3
6.833: S< b8c6
6.833: S< c2c3
6.833: S< g8f6
6.833: S< f1b5
6.833: S< time 12000
6.833: S< otim 11755
6.833: S< black
6.833: S< go
6.833: S> alibaba.ini found. Loading values....
...
6.911: S> Initializing transposition table (1048576 entries * 40) --> 41943040 bytes
6.911: S> Thinking output (pv lines) is on
6.911: S> opponent's name is Storm_06
6.911: S> 1 -18 0 37 Nf6xe4  .Bb5-c6  b7xc6  Nf3-e5
6.911: C< info depth 1 score cp -18 time 0 nodes 37 nps 37000 pv f6e4 b5c6 b7c6 f3e5
6.911: S> 3 -53 0 284 Bf8-c5   d2-d3
6.911: C< info depth 3 score cp -53 time 0 nodes 284 nps 284000 pv f8c5 d2d3
6.957: S> 5 -47 4 22182 Bf8-d6   d2-d3   h7-h6   b2-b4
6.957: C< info depth 5 score cp -47 time 40 nodes 22182 nps 554550 pv f8d6 d2d3 h7h6 b2b4
7.425: S> 6 -58 50 273120  a7-a6  Bb5-c6   d7xc6    0-0   Nf6xe4  Nf3-e5
7.425: C< info depth 6 score cp -58 time 500 nodes 273120 nps 546240 pv a7a6 b5c6 d7c6 e1g1 f6e4 f3e5
9.968: S> 7 7 305 1665909 Nf6xe4  Qd1-e2  Ne4-g5    0-0   Ng5xf3  Qe2-f3
9.968: C< info depth 7 score cp 7 time 3050 nodes 1665909 nps 546199 pv f6e4 d1e2 e4g5 e1g1 g5f3 e2f3
9.968: S> h7-h6  .Qf3-f7 Ke8xf7  Bb5-c6
13.790: S> 3732911 nodes (int:0, leaf:1839019, quies:0), 1893892 n/s
13.790: S> 4228132 reads, 0 hits ( 0.00%) 3829410627 writes
13.790: S> 10478636 moves in 0 times ( 0.00)
13.790: S> move Bf8-d6
13.790: C< bestmove f8d6

I used just a minimal simple one as I usually don't need it all, but it can fix a few known problems
for several WB programs. Better check my chronology details page :)
(A caveat: it is completely unfinished for the column about Pecularities + Bugs)

[Gabor Szots]

Thank you for the replies, particularly to Günther.

[Modern Times]

The source is available, so presumably that would be easily fixed, if you know what you are doing.