promotion bug : illegal move

[tissatussa]

i compiled Kojiro on Linux (Xubuntu 22.04) and it runs fine in CuteChess (GUI) but sometimes it makes an illegal move concerning promotion .. here are two examples :

[Event "?"]
[Site "?"]
[Date "2024.04.14"]
[Round "?"]
[White "Kojiro v0.1"]
[Black "Kittycat"]
[Result "0-1"]
[FEN "rnbqkb1r/ppp2ppp/5n2/3pp3/8/3PP3/PPPNNPPP/R1BQKB1R b KQkq - 3 4"]
[PlyCount "121"]
[SetUp "1"]
[Termination "illegal move"]
[TimeControl "900+3"]

1... Nc6 {+0.60/7 75s} 2. Ng3 {-0.39/12 21s} Be6 {+0.70/7 69s}
3. Be2 {-0.20/12 21s} Bc5 {+0.65/7 64s} 4. O-O {+0.02/12 22s} Qd6 {+0.55/7 44s}
5. a3 {+0.30/11 22s} O-O {+0.60/7 42s} 6. b4 {+3.59/14 22s} Bb6 {-0.35/8 34s}
7. c4 {+5.67/14 22s} Nd7 {-0.30/7 37s} 8. c5 {+5.69/14 23s} Nxc5 {-0.50/8 35s}
9. bxc5 {+5.77/13 23s} Bxc5 {-0.50/7 33s} 10. Nb3 {+5.81/12 23s}
Bb6 {-0.50/7 32s} 11. d4 {+5.58/12 23s} e4 {-0.55/6 30s} 12. Qc2 {+6.01/12 23s}
Rad8 {-0.60/5 28s} 13. Nc5 {+6.05/12 23s} Bxc5 {-0.70/8 21s}
14. dxc5 {+6.11/13 23s} Qe7 {-0.75/8 22s} 15. Rb1 {+6.02/12 22s}
Rb8 {-0.75/7 24s} 16. Bb2 {+6.28/11 22s} Qg5 {-0.85/7 23s}
17. Rbd1 {+6.35/10 22s} Ne7 {-0.85/7 19s} 18. Qa4 {+6.65/10 22s}
a6 {-0.80/7 21s} 19. Qc2 {+6.17/11 22s} Rfe8 {-0.75/6 20s}
20. Nh5 {+6.22/11 21s} Red8 {-0.90/6 19s} 21. h4 {+7.36/13 21s}
Qg6 {-1.35/7 14s} 22. Bxg7 {+7.29/12 21s} Bh3 {-1.40/6 17s}
23. Nf4 {+7.22/14 21s} Qxg7 {-1.75/7 16s} 24. Nxh3 {+7.13/13 20s}
Qe5 {-1.75/6 16s} 25. h5 {+7.14/11 20s} Nf5 {-1.80/6 15s} 26. Qb3 {+7.05/12 20s}
d4 {-1.75/7 11s} 27. Bc4 {+7.38/13 19s} dxe3 {-1.90/7 14s}
28. Rxd8+ {+8.62/13 19s} Rxd8 {-2.20/7 13s} 29. fxe3 {+8.62/12 19s}
Rd2 {-3.10/7 9.4s} 30. Bxf7+ {+8.68/12 18s} Kg7 {-2.70/6 12s}
31. Nf4 {+9.01/13 18s} Rb2 {-2.75/7 12s} 32. h6+ {+9.71/13 18s}
Kf6 {-3.00/6 11s} 33. Qc4 {+9.88/14 17s} Kg5 {-3.25/6 11s}
34. Bg8 {+9.54/13 17s} Nxe3 {-3.00/7 10s} 35. Qc1 {+8.42/14 17s}
Qxf4 {-3.00/7 9.6s} 36. Rxf4 {+8.90/17 16s} Rxg2+ {-3.10/9 7.1s}
37. Kh1 {+9.40/17 16s} Kxf4 {-2.80/9 6.1s} 38. Qe1 {+9.40/15 16s}
Rxg8 {-2.25/8 8.8s} 39. Qf2+ {+10.67/15 15s} Ke5 {-2.25/8 8.5s}
40. Qxe3 {+10.82/16 15s} Rg6 {-2.50/8 6.8s} 41. Qc3+ {+10.96/15 15s}
Kd5 {-2.50/7 6.8s} 42. Qg7 {+19.74/17 14s} Rc6 {-2.75/8 7.7s}
43. Qxh7 {+21.26/14 14s} Kxc5 {-2.75/7 4.9s} 44. Qg7 {+23.58/16 14s}
Rxh6+ {-6.30/7 4.9s} 45. Qxh6 {+24.52/18 13s} b5 {-6.70/7 4.8s}
46. Qxa6 {+26.88/21 13s} c6 {-7.60/8 4.7s} 47. Qa7+ {+27.04/20 13s}
Kc4 {-7.60/6 4.6s} 48. Qb7 {+27.27/20 12s} Kc5 {-7.90/8 4.6s}
49. Qe7+ {+25.66/18 12s} Kd5 {-7.90/6 4.5s} 50. Qd7+ {+27.28/22 12s}
Kc5 {-8.10/6 4.5s} 51. Qe6 {+28.53/22 12s} Kb6 {-8.10/7 4.4s}
52. Qxe4 {+30.09/23 11s} Kc5 {-8.75/7 4.3s} 53. Qe5+ {+27.77/22 11s}
Kc4 {-8.75/6 4.3s} 54. Kg2 {+27.93/22 11s} c5 {-8.75/7 4.2s}
55. Qe2+ {+28.02/19 11s} Kc3 {-9.10/7 4.2s} 56. Qxb5 {+53.91/21 10s}
c4 {-9.50/7 4.1s} 57. a4 {+M19/19 10s} Kd4 {-9.50/7 4.1s} 58. a5 {+M17/18 9.8s}
c3 {-10.00/8 4.0s} 59. a6 {+M15/17 9.6s} Ke3 {-16.90/7 4.0s}
60. a7 {+M9/16 9.3s} Kd2 {-M8/7 4.0s} 61. a8=Q {+M7/15 9.1s}
Kc1 {-M6/6 3.9s, White makes an illegal move: a7a8Q} 0-1

[Event "?"]
[Site "?"]
[Date "2024.04.14"]
[Round "?"]
[White "Kojiro v0.1"]
[Black "Athene v0.1"]
[Result "0-1"]
[FEN "rnbqkb1r/ppp2ppp/5n2/3pp3/8/3PP3/PPPNNPPP/R1BQKB1R b KQkq - 3 4"]
[PlyCount "95"]
[SetUp "1"]
[Termination "illegal move"]
[TimeControl "900+3"]

1... Bg4 {+0.40/6 33s} 2. c4 {-0.57/12 21s} Nc6 {+0.35/6 32s}
3. cxd5 {-0.38/12 21s} Nxd5 {+0.45/6 31s} 4. a3 {-0.15/12 22s} Bd6 {+0.50/6 30s}
5. h3 {-0.02/12 22s} Be6 {+0.40/6 29s} 6. Ng3 {+0.07/12 22s} f5 {+0.70/6 28s}
7. e4 {+0.11/12 22s} fxe4 {+0.55/6 28s} 8. dxe4 {+0.11/11 23s} Nf4 {+0.55/6 27s}
9. Nf3 {-0.07/10 23s} Qf6 {+0.60/5 26s} 10. Qc2 {-0.29/11 23s}
Nxh3 {+0.50/5 25s} 11. Ba6 {-0.17/11 23s} Nb4 {+1.10/6 24s}
12. axb4 {+0.77/13 23s} bxa6 {+0.50/6 24s} 13. Rxh3 {+0.76/12 23s}
Bxh3 {+1.10/6 23s} 14. Bg5 {+1.30/13 23s} Bxb4+ {+1.10/7 22s}
15. Ke2 {+1.31/12 22s} Qb6 {+1.10/6 22s} 16. gxh3 {+1.42/13 22s}
Qb5+ {+1.00/6 21s} 17. Qd3 {+1.44/13 22s} Bd6 {+0.90/7 20s}
18. Qxb5+ {+2.08/14 22s} axb5 {+0.10/7 20s} 19. Nf5 {+1.99/14 22s}
g6 {+0.70/6 19s} 20. Nxd6+ {+3.92/16 21s} cxd6 {-0.15/7 19s}
21. Rd1 {+4.01/16 21s} Kd7 {-0.40/7 18s} 22. Nxe5+ {+4.49/15 21s}
Ke6 {-0.40/7 18s} 23. Nf3 {+4.51/14 21s} a6 {-0.50/7 17s} 24. Rd5 {+4.92/13 20s}
Rab8 {-0.60/7 17s} 25. Bf4 {+5.81/15 20s} Rb6 {-1.45/7 16s}
26. Ng5+ {+5.99/14 20s} Kd7 {-2.45/7 16s} 27. Bxd6 {+6.13/16 19s}
Kc8 {-2.40/7 15s} 28. Be5 {+6.51/14 19s} Re8 {-2.45/7 15s}
29. Nf7 {+7.18/16 19s} Kb7 {-2.40/7 15s} 30. Nd6+ {+7.13/16 18s}
Rxd6 {-2.35/9 14s} 31. Bxd6 {+7.31/17 18s} Rxe4+ {-2.35/7 14s}
32. Kf3 {+7.18/15 18s} Rh4 {-2.40/8 14s} 33. Kg3 {+7.44/16 17s}
Kc6 {-2.45/8 13s} 34. Kxh4 {+8.71/19 17s} Kxd5 {-2.45/9 13s}
35. Bf8 {+9.42/21 17s} Ke4 {-2.50/9 12s} 36. Kg5 {+9.73/23 16s}
Kf3 {-3.30/9 12s} 37. Bc5 {+10.11/22 16s} Kg2 {-3.40/9 12s}
38. h4 {+10.60/24 16s} Kh3 {-3.40/9 12s} 39. b4 {+13.01/22 15s}
Kh2 {-3.40/9 11s} 40. Kh6 {+14.71/23 15s} Kh3 {-3.40/10 11s}
41. Be7 {+29.92/24 15s} Kg4 {-3.50/10 11s} 42. Kxh7 {+30.20/23 14s}
Kf3 {-3.50/9 10s} 43. Kxg6 {+40.13/24 14s} Kf4 {-9.95/9 10s}
44. h5 {+41.03/23 14s} Ke5 {-12.30/9 10.0s} 45. h6 {+41.60/22 13s}
Ke6 {-13.40/9 9.8s} 46. Bc5 {+41.64/20 13s} a5 {-14.35/9 9.5s}
47. h7 {+M15/19 13s} axb4 {-14.35/8 9.3s} 48. h8=Q {+M11/18 12s}
Kd7 {-14.40/7 9.1s, White makes an illegal move: h7h8Q} 0-1

[tissatussa]

did you consider to look into this Issue ?

[Babak-SSH]

I checked the positions first in the Terminal to verify the output and then proceeded to try the positions in Arena Chess which is the usual GUI I use and promoted the queen with no problem in those two positions, furthermore, I tried the positions in lichess and played with Kojiro to verify there is no problem in the output of the UCI.

Having said that there's clearly a problem with my promotion move output and the CuteChess GUI, so I did a little bit of digging and found this issue thread which furthermore strengthens my suspicion that CuteChess GUI doesn't accept upper case for promotions.

these two promotion moves are upper cases because I use upper cases for white and lower cases for black, which isn't against UCI protocol afaik, and is kind of an aesthetic decision that follows the pattern of FEN format. I might think about removing it in other versions.

for now, if you want to try the bot with CuteChess GUI I guess replacing uppercase letters in promoted_pieces array with lowercase ones will solve the problem, it will only affect PV and bestmove output in UCI.

@tissatussa btw thanks for trying out my bot :)

[tissatussa]

..replacing uppercase letters in promoted_pieces array with lowercase ones will solve the problem..

indeed, that's it !
this way i compiled successfully and the binary plays valid games in CuteChess GUI, also with promotions !

you should update the source code accordingly and create v0.1.1 ?

[tissatussa]

btw. when compiling, i didn't get any errors, but lots of warnings !? i guess they're easy to fix - and you should ?