title: Is it possible to lose to "Worstfish"?

text:
# Question
Title: Is it possible to lose to "Worstfish"?
I just found out about Stockfish's stupid little brother, Worstfish. Worstfish calculates the worst move in every position and plays it. Because of this, is it possible to lose against it? If you give it a mate in one, it obviously won't play it because it would be the best move. But is it possible to force your opponent to checkmate you? I hope somebody knows if this is possible or not.

# Answer
Here's an example found by googling "lose to worstfish chess" and following the first hit that comes up (a reddit thread)

In case of link rot the game is below. I note WorstFish opens with the Grob

```
[Event "Casual Rapid game"]
[Site "https://lichess.org/S9GDQ5Pr"]
[Date "2023.09.15"]
[White "WorstFish"]
[Black "EdwinBrum"]
[Result "1-0"]
[UTCDate "2023.09.15"]
[UTCTime "08:08:41"]
[WhiteElo "1500"]
[BlackElo "1721"]
[WhiteTitle "BOT"]
[Variant "Standard"]
[TimeControl "600+0"]
[ECO "A00"]
[Opening "Grob Opening"]
[Termination "Normal"]
[Annotator "lichess.org"]
[FEN ""]

1. g4? { (0.15 → -1.46) Mistake. e4 was best. } { A00 Grob Opening } (1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. d3 Bc5 5. c3 O-O) 1... e5 2. f4?? { (-0.93 → Mate in 1) Checkmate is now unavoidable. Bg2 was best. } (2. Bg2 Nc6 3. Nc3 Nge7 4. e3 d5 5. d4 exd4 6. exd4 Be6) 2... h5?? { (Mate in 1 → -1.82) Lost forced checkmate sequence. Qh4# was best. } (2... Qh4#) 3. f5?? { (-1.82 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (3. g5 exf4 4. d4 Qxg5 5. Nf3 Qf6 6. Nc3 Bb4 7. Qd2 d5) 3... g5?? { (Mate in 1 → -0.68) Lost forced checkmate sequence. Qh4# was best. } (3... Qh4#) 4. fxg6?? { (-0.68 → Mate in 1) Checkmate is now unavoidable. d3 was best. } (4. d3 d5 5. e4 dxe4 6. Nc3 exd3 7. Bxd3 Nc6 8. Bd2 Bd7 9. h4 hxg4 10. Qxg4 Nf6) 4... f5?? { (Mate in 1 → -0.94) Lost forced checkmate sequence. Qh4# was best. } (4... Qh4#) 5. a4?? { (-0.94 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (5. g5 Nc6 6. d4 Nxd4 7. Nf3 Nxf3+ 8. exf3 d5 9. f4 Ne7 10. fxe5 Nxg6 11. Nc3 c6) 5... a5?? { (Mate in 1 → -0.70) Lost forced checkmate sequence. Qh4# was best. } (5... Qh4#) 6. Ra2?? { (-0.70 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (6. g5) 6... d5?? { (Mate in 1 → -2.95) Lost forced checkmate sequence. Qh4# was best. } (6... Qh4#) 7. b4?? { (-2.95 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (7. g5 Qxg5 8. Nf3 Qf6 9. d3 f4 10. e3 fxe3 11. Bxe3 Bg4 12. Bg2 Nc6 13. O-O Qxg6) 7... c5?? { (Mate in 1 → -2.79) Lost forced checkmate sequence. Qh4# was best. } (7... Qh4#) 8. Bb2?? { (-2.79 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (8. g5 axb4 9. c3 Qxg5 10. Nf3 Qf6 11. d3 e4 12. Bg5 Qxg6 13. dxe4 fxe4 14. Qxd5 exf3) 8... b5?? { (Mate in 1 → -0.74) Lost forced checkmate sequence. Qh4# was best. } (8... Qh4#) 9. c4?? { (-0.74 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (9. g5 Bg7) 9... h4?? { (Mate in 1 → 1.50) Lost forced checkmate sequence. Qh4# was best. } (9... Qh4#) 10. Bd4?? { (1.50 → -3.98) Blunder. Bxe5 was best. } (10. Bxe5) 10... h3?? { (-3.98 → -1.81) Blunder. cxd4 was best. } (10... cxd4 11. axb5 fxg4 12. bxa5 Rxa5 13. Rxa5 Qxa5 14. h3 e4 15. hxg4 Bd6 16. Qc2 Nf6 17. Nf3) 11. Ba1?? { (-1.81 → Mate in 1) Checkmate is now unavoidable. Bxe5 was best. } (11. Bxe5 Nc6 12. Bg3 bxc4 13. bxc5 fxg4 14. Nc3 Nf6 15. e4 Nb4 16. Nxd5 Nfxd5 17. Bxc4 Qe7) 11... f4?? { (Mate in 1 → -1.16) Lost forced checkmate sequence. Qh4# was best. } (11... Qh4#) 12. Bc3?? { (-1.16 → Mate in 1) Checkmate is now unavoidable. g5 was best. } (12. g5) 12... e4?? { (Mate in 1 → -1.63) Lost forced checkmate sequence. Qh4# was best. } (12... Qh4#) 13. Be5?? { (-1.63 → Mate in 1) Checkmate is now unavoidable. Qc2 was best. } (13. Qc2 axb4 14. Bxh8 Qh4+ 15. Kd1 bxc4 16. Qb2 Nc6 17. Nxh3 Qxg4 18. Rg1 Qh4 19. Nc3 bxc3) 13... d4?? { (Mate in 1 → -0.68) Lost forced checkmate sequence. Qh4# was best. } (13... Qh4#) 14. Nc3?? { (-0.68 → Mate in 1) Checkmate is now unavoidable. Qb3 was best. } (14. Qb3 Rh6) 14... f3?? { (Mate in 1 → 2.59) Lost forced checkmate sequence. Qh4# was best. } (14... Qh4#) 15. Bg7?? { (2.59 → Mate in 1) Checkmate is now unavoidable. Nxe4 was best. } (15. Nxe4 bxc4 16. Nxf3 Rh6 17. g7 Be7 18. g5 Rg6 19. Qc2 Nc6 20. Nxc5 Nxe5 21. Nxe5 Rxg7) 15... e3?? { (Mate in 1 → -3.50) Lost forced checkmate sequence. Qh4# was best. } (15... Qh4#) 16. Be5?? { (-3.50 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (16. Nxf3 Bxg7 17. Nxb5 axb4 18. dxe3 dxe3 19. Qb3 Qe7 20. Qd3 b3 21. Qxb3 Nc6 22. Ra3 Nb4) 16... d3?? { (Mate in 1 → 2.90) Lost forced checkmate sequence. f2# was best. } (16... f2#) 17. Bf4?? { (2.90 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (17. Nxf3) 17... Nc6?? { (Mate in 1 → 0.88) Lost forced checkmate sequence. f2# was best. } (17... f2#) 18. Bh6?? { (0.88 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (18. Nxf3 Nge7 19. dxe3 Nxb4 20. Nxb5 Nxg6 21. Rd2 Bb7 22. g5 Nxf4 23. exf4 Bxf3 24. exf3) 18... Nd4?? { (Mate in 1 → -3.38) Lost forced checkmate sequence. f2# was best. } (18... f2#) 19. Bf4?? { (-3.38 → Mate in 1) Checkmate is now unavoidable. Bxe3 was best. } (19. Bxe3 axb4 20. Bxd4 bxc3 21. Nxf3 cxd4 22. Qb3 c2 23. Ra1 Ne7 24. exd3 Nxg6 25. Be2 bxc4) 19... Nc2+? { (Mate in 1 → -7.24) Lost forced checkmate sequence. f2# was best. } (19... f2#) 20. Rxc2? { (-7.24 → Mate in 1) Checkmate is now unavoidable. Qxc2 was best. } (20. Qxc2 dxc2 21. Rxc2 f2+ 22. Kd1 axb4 23. Nd5 Ra7 24. Nxh3 bxc4 25. Nxe3 Qd4 26. a5 Qa1+) 20... Nf6?? { (Mate in 1 → 1.46) Lost forced checkmate sequence. f2# was best. } (20... f2#) 21. g5?? { (1.46 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (21. Nxf3 dxc2 22. Qxc2 Bg7 23. Bxe3 cxb4 24. Nxb5 O-O 25. Bxh3 Nxg4 26. Bg5 Bf6 27. c5 Bxg5) 21... Nd5?? { (Mate in 1 → 0.19) Lost forced checkmate sequence. f2# was best. } (21... f2#) 22. Nb1?? { (0.19 → Mate in 1) Checkmate is now unavoidable. dxe3 was best. } (22. dxe3) 22... Nc3?? { (Mate in 1 → -5.35) Lost forced checkmate sequence. f2# was best. } (22... f2#) 23. Rc1?? { (-5.35 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (23. Nxf3 Nxd1 24. Rc1 Nf2 25. bxc5 Bxc5 26. g7 Rg8 27. cxb5 Qe7 28. Ne5 Rxg7 29. Nc6 Qe4) 23... Na2?? { (Mate in 1 → 2.21) Lost forced checkmate sequence. f2# was best. } (23... f2#) 24. Na3?? { (2.21 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (24. Nxf3 axb4 25. cxb5 Qd5 26. dxe3 Nxc1 27. Qxc1 Bg7 28. Nbd2 O-O 29. Kf2 Rxa4 30. e4 Qd7) 24... Nc3?? { (Mate in 1 → -2.58) Lost forced checkmate sequence. f2# was best. } (24... f2#) 25. Bb8?? { (-2.58 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (25. Nxf3 Nxd1) 25... Ne4?? { (Mate in 1 → -1.20) Lost forced checkmate sequence. f2# was best. } (25... f2#) 26. Rb1?? { (-1.20 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (26. Nxf3) 26... Nc3?? { (Mate in 1 → -4.50) Lost forced checkmate sequence. f2# was best. } (26... f2#) 27. Ba7?? { (-4.50 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (27. Nxf3 Nxd1 28. Be5 Bb7 29. Bf6 Be7 30. Bxh8 Bxf3 31. exf3 Bxg5 32. Be5 e2 33. Bxe2 dxe2) 27... Ne4?? { (Mate in 1 → -2.98) Lost forced checkmate sequence. f2# was best. } (27... f2#) 28. Rb2?? { (-2.98 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (28. Nxf3 Bg4 29. g7 Bxg7 30. Bxc5 exd2+ 31. Nxd2 Bc3 32. Be3 O-O 33. cxb5 Rc8 34. Rc1 Rf7) 28... Qf6?? { (Mate in 1 → -4.91) Lost forced checkmate sequence. f2# was best. } (28... f2#) 29. Rc2?? { (-4.91 → Mate in 1) Checkmate is now unavoidable. Qb1 was best. } (29. Qb1 exd2+) 29... Qc3?? { (Mate in 1 → -5.27) Lost forced checkmate sequence. f2# was best. } (29... f2#) 30. Bb8?? { (-5.27 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (30. Nxf3 dxc2 31. Qxc2 Qxc2 32. Nxc2 Rxa7 33. cxb5 axb4 34. Bxh3 Bxh3 35. b6 Rd7 36. Nxe3 Bg7) 30... Rh4?? { (Mate in 1 → -3.99) Lost forced checkmate sequence. f2# was best. } (30... f2#) 31. Ra2?? { (-3.99 → Mate in 1) Checkmate is now unavoidable. exd3 was best. } (31. exd3 exd2+ 32. Qxd2 f2+ 33. Kd1 Qxa3 34. Qe3 Qa1+ 35. Qc1 Bg4+ 36. Ne2 Qd4 37. Qb2 Rxb8) 31... Rg4?? { (Mate in 1 → -0.64) Lost forced checkmate sequence. f2# was best. } (31... f2#) 32. Qc1?? { (-0.64 → Mate in 1) Checkmate is now unavoidable. Nxf3 was best. } (32. Nxf3) 32... f2+ 33. Kd1 dxe2+?? { (Mate in 10 → -3.85) Lost forced checkmate sequence. fxg1=Q was best. } (33... fxg1=Q 34. Qxc3 Nxc3+ 35. Kc1 dxe2 36. Rxg1 e1=Q+ 37. Kb2 Bf5 38. dxc3 cxb4 39. Nc2 bxc3+ 40. Kb3) 34. Bxe2?? { (-3.85 → Mate in 3) Checkmate is now unavoidable. Nxe2 was best. } (34. Nxe2 Qxc1+ 35. Kxc1 exd2+ 36. Rxd2 Nxd2 37. Bf4 Nb3+ 38. Kb2 Nd4 39. Be5 Bb7 40. Nxd4 cxd4) 34... Qxd2+?? { (Mate in 3 → -5.80) Lost forced checkmate sequence. Rxg1+ was best. } (34... Rxg1+ 35. Rxg1 fxg1=Q+ 36. Bf1 Qxf1#) 35. Qxd2 Ke7?? { (-6.89 → 8.79) Blunder. Rxg1+ was best. } (35... Rxg1+ 36. Kc2 Nxd2 37. Kd3 Rxh1 38. Kxe3 f1=Q 39. Bxf1 Nxf1+ 40. Kf4 Rxb8 41. Nxb5 Rxh2 42. Rxh2) 36. Bf3?? { (8.79 → -14.21) Blunder. Qxe3 was best. } (36. Qxe3 fxg1=B 37. Rxg1 Rxg1+ 38. Qxg1 Rxb8 39. Bf3 Bf5 40. Bxe4 Bxe4 41. Qxc5+ Ke6 42. Qe3 Ke5) 36... Ke6?? { (-14.21 → Mate in 3) Checkmate is now unavoidable. f1=Q+ was best. } (36... f1=Q+ 37. Kc2 exd2 38. Nxh3 Qxf3 39. Be5 Bf5 40. Kb2 d1=Q 41. Rxd1 Rg2+ 42. Kc1 Qe3+ 43. Rad2) 37. Qc2?? { (Mate in 3 → Mate in 1) Lost forced checkmate sequence. Qd5+ was best. } (37. Qd5+ Ke7 38. Qf7+ Kd8 39. Bc7#) 37... Kf5?? { (Mate in 1 → 13.10) Lost forced checkmate sequence. f1=Q# was best. } (37... f1=Q#) 38. Nb1?? { (13.10 → Mate in 1) Checkmate is now unavoidable. Bxg4+ was best. } (38. Bxg4+ Kxg4 39. Qxe4+ Kh5 40. Ne2 Bg4 41. Qxa8 bxc4 42. bxa5 Bg7 43. Qe4 Bd4 44. Nxc4 Bxe2+) 38... Rxb8?? { (Mate in 1 → 9.61) Lost forced checkmate sequence. f1=Q# was best. } (38... f1=Q#) 39. g7?? { (9.61 → Mate in 1) Checkmate is now unavoidable. Bxg4+ was best. } (39. Bxg4+ Ke5 40. Nf3+ Kf4 41. Bxc8 Rxc8 42. Ke2 Re8 43. cxb5 Nxg5 44. Qc4+ Re4 45. Qc3 Re6) 39... Bxg7?? { (Mate in 1 → 9.02) Lost forced checkmate sequence. f1=Q# was best. } (39... f1=Q#) 40. Na3?? { (9.02 → Mate in 1) Checkmate is now unavoidable. Bxg4+ was best. } (40. Bxg4+ Ke5 41. Nf3+ Kf4 42. Bxc8 Rxc8 43. Ke2 Re8 44. bxc5 b4 45. Qd3 Bf8 46. Qxe3+ Kg4) 40... Be6?? { (Mate in 1 → 9.07) Lost forced checkmate sequence. f1=Q# was best. } (40... f1=Q#) 41. Rb2?? { (9.07 → Mate in 1) Checkmate is now unavoidable. Bxg4+ was best. } (41. Bxg4+ Ke5 42. Nf3+ Kf4 43. Bxe6 Nc3+ 44. Kc1 Rf8 45. cxb5 Kxf3 46. bxa5 Kf4 47. Qd3 Be5) 41... Bxc4?? { (Mate in 1 → 9.68) Lost forced checkmate sequence. f1=Q# was best. } (41... f1=Q#) 42. Rb1?? { (9.68 → Mate in 1) Checkmate is now unavoidable. Bxg4+ was best. } (42. Bxg4+ Ke5 43. Nxc4+ bxc4 44. Ne2 Kd5 45. Bf3 Re8 46. Nf4+ Kd4 47. bxa5 e2+ 48. Kxe2 Nxg5+) 42... Rd8+ 43. Qd2 Ng3? { (Mate in 2 → -7.43) Lost forced checkmate sequence. f1=Q+ was best. } (43... f1=Q+ 44. Kc2 Rxd2#) 44. Rc1? { (-7.43 → Mate in 1) Checkmate is now unavoidable. Bxg4+ was best. } (44. Bxg4+ Kxg4 45. Nf3 Be2+ 46. Kc2 exd2 47. Nxd2 Bd3+ 48. Kb3 c4+ 49. Ndxc4 bxc4+ 50. Nxc4 Nxh1) 44... e2+?? { (Mate in 1 → -3.38) Lost forced checkmate sequence. Rxd2# was best. } (44... Rxd2#) 45. Kc2?? { (-3.38 → Mate in 7) Checkmate is now unavoidable. Nxe2 was best. } (45. Nxe2 Nxh1) 45... Ke5?? { (Mate in 7 → 6.74) Lost forced checkmate sequence. Rxd2+ was best. } (45... Rxd2+ 46. Kxd2 Rd4+ 47. Kc2 Bd3+ 48. Kd2 e1=Q+ 49. Rxe1 Bb1+ 50. Ke3 fxe1=Q+ 51. Be2 Rd3#) 46. Rf1?? { (6.74 → Mate in 6) Checkmate is now unavoidable. Qe3+ was best. } (46. Qe3+ Ne4 47. Nxc4+ bxc4 48. Bxg4 Rd2+ 49. Qxd2 fxg1=Q 50. Rhxg1 Nxd2 51. Kxd2 cxb4 52. Rxc4 Kd5) 46... Rd3?? { (Mate in 6 → 0.68) Lost forced checkmate sequence. Rxd2+ was best. } (46... Rxd2+ 47. Kxd2 Nxf1+ 48. Kc2 Ne3+ 49. Kb2 Kf5+ 50. Kc1 e1=Q+ 51. Bd1 Qxd1#) 47. Bd5?? { (0.68 → Mate in 5) Checkmate is now unavoidable. Nxe2 was best. } (47. Nxe2) 47... Kd4?? { (Mate in 5 → 2.24) Lost forced checkmate sequence. Rxd2+ was best. } (47... Rxd2+ 48. Kxd2 Nxf1+ 49. Kc1 e1=Q+ 50. Kb2 Kxd5+ 51. Kc2 Ne3#) 48. g6?? { (2.24 → Mate in 5) Checkmate is now unavoidable. Nxe2+ was best. } (48. Nxe2+ Kxd5 49. hxg3 Rxd2+ 50. Kxd2 axb4 51. Nxb5 Rxg5 52. Rxf2 Kc6 53. Rxh3 Rd5+ 54. Ke1 b3) 48... Re4?? { (Mate in 5 → -4.13) Lost forced checkmate sequence. Rxd2+ was best. } (48... Rxd2+ 49. Kxd2 Nxf1+ 50. Kc1 e1=Q+ 51. Kc2 Ne3+ 52. Kb2 Kxd5#) 49. Kc1?? { (-4.13 → Mate in 4) Checkmate is now unavoidable. Nxe2+ was best. } (49. Nxe2+ Rxe2 50. Qxe2 Rc3+ 51. Kb1 Bxe2 52. Nxb5+ Bxb5 53. axb5 Nxf1 54. Rxf1 Kxd5 55. Rxf2 Rb3+) 49... Be5?? { (Mate in 4 → 0.00) Lost forced checkmate sequence. exf1=Q+ was best. } (49... exf1=Q+ 50. Kb2 Rxd2+ 51. Nc2+ Kxd5+ 52. Ka3 Qd3#) 50. Qa2?? { (0.00 → Mate in 3) Checkmate is now unavoidable. Nf3+ was best. } (50. Nf3+ Kxd5 51. g7 exf1=Q+ 52. Rxf1 Ne2+ 53. Kb1 Bxg7 54. Qg5+ Re5 55. Qxg7 Rb3+ 56. Kc2 Rxf3) 50... Kc3?? { (Mate in 3 → Mate in 1) Lost forced checkmate sequence. exf1=Q+ was best. } (50... exf1=Q+ 51. Kc2 Qd1+ 52. Kb2 Kxd5#) 51. Be6?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qb2# was best. } (51. Qb2#) 51... Rd2?? { (Mate in 1 → Mate in 2) Lost forced checkmate sequence. exf1=Q# was best. } (51... exf1=Q#) 52. Bd7?? { (Mate in 2 → Mate in 1) Lost forced checkmate sequence. Nxb5+ was best. } (52. Nxb5+ Kxb4 53. Qa3#) 52... Re3?? { (Mate in 1 → 10.68) Lost forced checkmate sequence. exf1=Q# was best. } (52... exf1=Q#) 53. Bf5?? { (10.68 → Mate in 1) Checkmate is now unavoidable. Qxd2+ was best. } (53. Qxd2+ Kb3 54. Qxe3+ Bc3 55. Rxf2 e1=R+ 56. Qxe1 Bxe1 57. Rf3+ Bc3 58. Rxg3 Bd5 59. Nxb5 cxb4) 53... Bd4?? { (Mate in 1 → 3.91) Lost forced checkmate sequence. exf1=Q# was best. } (53... exf1=Q#) 54. Be4?? { (3.91 → Mate in 1) Checkmate is now unavoidable. Nxb5+ was best. } (54. Nxb5+ Kxb4 55. Qxd2+ Bc3 56. Nxc3 e1=Q+ 57. Rxe1 fxe1=Q+ 58. Qxe1 Rxe1+ 59. Kd2 Rf1 60. hxg3 Rf2+) 54... Nxe4?! { (Mate in 1 → -13.63) Lost forced checkmate sequence. exf1=Q# was best. } (54... exf1=Q#) 55. Re1?! { (-13.63 → Mate in 1) Checkmate is now unavoidable. Nxb5+ was best. } (55. Nxb5+ Bxb5 56. Qa3+ Kc4 57. Nf3 Rxa3 58. Nxd2+ Nxd2 59. Kxd2 Ra2+ 60. Kc1 exf1=Q+ 61. Rxf1 Ra1+) 55... Bd3?? { (Mate in 1 → -5.37) Lost forced checkmate sequence. fxe1=Q# was best. } (55... fxe1=Q#) 56. Nc4?? { (-5.37 → Mate in 1) Checkmate is now unavoidable. Nxe2+ was best. } (56. Nxe2+ Kxb4 57. Qxd2+ Nxd2 58. Kxd2 fxe1=Q+ 59. Rxe1 Bxg6 60. Nxd4 Rd3+ 61. Kc1 Rxa3 62. Nc6+ Kxa4) 56... Rc2+? { (Mate in 1 → -8.84) Lost forced checkmate sequence. fxe1=Q# was best. } (56... fxe1=Q#) 57. Kb1? { (-8.84 → Mate in 1) Checkmate is now unavoidable. Qxc2+ was best. } (57. Qxc2+ Bxc2 58. Nxe2+ Kxc4 59. Kxc2 fxe1=Q 60. Rxe1 axb4 61. Kc1 Nc3 62. a5 b3 63. a6 Re8) 57... Rb2+ 58. Kc1 Rc2+? { (Mate in 1 → -9.60) Lost forced checkmate sequence. fxe1=Q# was best. } (58... fxe1=Q#) 59. Kb1? { (-9.60 → Mate in 1) Checkmate is now unavoidable. Qxc2+ was best. } (59. Qxc2+ Bxc2 60. Nxe2+ Kxc4 61. Kxc2 axb4 62. Kd1 fxe1=R+ 63. Rxe1 Nc3+ 64. Nxc3 Rxe1+ 65. Kxe1 Bxc3+) 59... Nd2+ 60. Nxd2 Rb2+ 61. Kc1 c4?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. fxe1=Q# was best. } (61... fxe1=Q#) 62. Qb1?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qxb2# was best. } (62. Qxb2#) 62... Rc2+?? { (Mate in 1 → 3.05) Lost forced checkmate sequence. fxe1=Q# was best. } (62... fxe1=Q#) 63. Qxc2+ Kxb4 64. Qa2?? { (2.39 → Mate in 1) Checkmate is now unavoidable. Rxe2 was best. } (64. Rxe2 fxg1=B) 64... Kc3?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. fxe1=Q# was best. } (64... fxe1=Q#) 65. g7?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qb2# was best. } (65. Qb2#) 65... b4?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. fxe1=Q# was best. } (65... fxe1=Q#) 66. g8=N?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qa1# was best. } (66. Qa1#) 66... Bc2?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. fxe1=Q# was best. } (66... fxe1=Q#) 67. Qb1?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qxc2# was best. } (67. Qxc2#) 67... Kd3?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. fxe1=Q# was best. } (67... fxe1=Q#) 68. Ne4?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qxc2# was best. } (68. Qxc2#) 68... Bc3?? { (Mate in 1 → 14.95) Lost forced checkmate sequence. fxe1=Q# was best. } (68... fxe1=Q#) 69. Ngf6?? { (14.95 → Mate in 1) Checkmate is now unavoidable. Qxc2+ was best. } (69. Qxc2+ Kd4 70. Nxe2+ Ke5 71. Nxf2 b3 72. Ng4+ Ke6 73. Nf4+ Kd6 74. Qg6+ Kc5 75. Rxe3 Bd4) 69... Bd2+? { (Mate in 1 → -7.11) Lost forced checkmate sequence. fxe1=Q# was best. } (69... fxe1=Q#) 70. Nxd2? { (-7.11 → Mate in 7) Checkmate is now unavoidable. Kb2 was best. } (70. Kb2 c3+ 71. Ka2 Bxb1+ 72. Rxb1 f1=Q 73. Nxe2 Qxe2 74. Nc5+ Kc4 75. Nb3 Bc1+ 76. Ka1 Bb2+) 70... fxe1=Q+ 71. Kb2 Qc1+?? { (Mate in 6 → -4.80) Lost forced checkmate sequence. Qxd2 was best. } (71... Qxd2 72. Ne4 Kxe4 73. Qxc2+ Qxc2+ 74. Kxc2 e1=Q 75. Nf3 Re2+ 76. Nd2+ Rxd2#) 72. Ka2?? { (-4.80 → Mate in 1) Checkmate is now unavoidable. Qxc1 was best. } (72. Qxc1 c3+ 73. Ka1 e1=Q 74. Ne2 Qxd2 75. Nf4+ Kc4 76. Nd7 Qxc1+ 77. Rxc1 b3 78. Nb6+ Kc5) 72... Kc3?? { (Mate in 1 → 8.34) Lost forced checkmate sequence. Qa3# was best. } (72... Qa3#) 73. Nh7?? { (8.34 → Mate in 1) Checkmate is now unavoidable. Nxe2+ was best. } (73. Nxe2+ Rxe2 74. Qxc1 Kd3 75. Rf1 Kd4 76. Ka1 c3 77. Qxc2 Rxd2 78. Qe4+ Kc5 79. Rf5+ Rd5) 73... Re4?? { (Mate in 1 → 9.69) Lost forced checkmate sequence. Qa3# was best. } (73... Qa3#) 74. Nf1?? { (9.69 → Mate in 1) Checkmate is now unavoidable. Nxe4+ was best. } (74. Nxe4+ Kd4 75. Qxc1 Bd1 76. Qf4 e1=Q 77. Nf3+ Bxf3 78. Rxe1 c3 79. Nxc3+ Kxc3 80. Qe3+ Kc4) 74... Rd4?? { (Mate in 1 → Mate in 9) Lost forced checkmate sequence. Qxb1# was best. } (74... Qxb1#) 75. Nd2?? { (Mate in 9 → Mate in 1) Lost forced checkmate sequence. Nxe2+ was best. } (75. Nxe2+ Kd3 76. Qxc1 Ke4 77. Qg5 Bb1+ 78. Ka1 Rd6 79. Nfg3+ Kd3 80. Kxb1 c3 81. Qf4 c2+) 75... Bd3?? { (Mate in 1 → Mate in 6) Lost forced checkmate sequence. Qa3# was best. } (75... Qa3#) 76. Nb3?? { (Mate in 6 → Mate in 1) Lost forced checkmate sequence. Qxc1+ was best. } (76. Qxc1+ Bc2 77. Ndf3 Kd3 78. Nf6 b3+ 79. Ka3 Kc3 80. Nxe2+ Kd3 81. Qd2#) 76... Qb2+?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qxb1# was best. } (76... Qxb1#) 77. Qxb2# { White wins by checkmate. } 1-0

```
> 19 votes

# Answer
There is a significant difference between making the worst move assuming best play and the worst move assuming worst play. The former is what Worstfish does (as far as I understand), but the latter is what would be the best strategy when trying to lose against an opponent that also tries to lose.

A game with standard chess rules but where both sides try to lose is sometimes also referred to as misere chess. Fairy-Stockfish supports it and also has an NNUE network trained for misere chess. As expected the best strategy actually is to more or less play normal chess trying to win material and only once you are significantly up in material you can use zugzwang to force your opponent to checkmate you. Below are two example games of Fairy-SF as white playing against a human player:

(The sidelines are automatic analysis from lichess, can be ignored)

https://lichess.org/eHYEox53

```
[Event "Casual Rapid game"]
[Site "https://lichess.org/eHYEox53"]
[Date "2022.05.31"]
[White "BortElGrasitas"]
[Black "forsenRage"]
[Result "0-1"]
[UTCDate "2022.05.31"]
[UTCTime "21:21:23"]
[WhiteElo "1500"]
[BlackElo "1972"]
[Variant "Standard"]
[TimeControl "720+3"]
[ECO "A13"]
[Opening "English Opening: Agincourt Defense"]
[Termination "Normal"]
[Annotator "lichess.org"]
[FEN ""]

1. c4 e6 { A13 English Opening: Agincourt Defense } 2. d4 Ke7?? { (0.26 → 2.74) Blunder. Nf6 was best. } (2... Nf6 3. Nf3 d5 4. Nc3 c6 5. Bg5 h6 6. Bxf6 Qxf6 7. e3) 3. e4 Kd6?! { (2.58 → 3.39) Inaccuracy. Ke8 was best. } (3... Ke8 4. Nc3 Bb4 5. Ne2 Be7 6. Be3 d6 7. Qc2 Bd7 8. O-O-O) 4. Nc3 Ne7?? { (3.08 → Mate in 2) Checkmate is now unavoidable. Ke7 was best. } (4... Ke7 5. Bg5+ f6 6. Be3 Ke8 7. Qa4 Nh6 8. Be2 Nf7 9. Nf3 a5 10. a3 b6 11. b4) 5. e5+ Kc6 6. d5+ Kc5 7. Ne4+ Kb4 8. Qb3+ Ka5 9. Bd2+ Ka6 10. Qa3+ Kb6 11. Qb4+ Ka6 12. c5+ b5 13. cxb6+ Kb7 14. bxa7+ Kxa7 15. Be3+ c5 16. Bxc5+ Qb6 17. Bxb6+ Kb7 18. Bd8+ Ka7 19. Bb6+ Kb7 20. Bc5+ Kc7 21. d6+?! { (Mate in 1 → 27.08) Lost forced checkmate sequence. Qb6# was best. } (21. Qb6#) 21... Kc6?! { (27.08 → Mate in 2) Checkmate is now unavoidable. Kd8 was best. } (21... Kd8 22. dxe7+ Bxe7 23. Bxe7+ Ke8 24. Bb5 Na6 25. Bxa6 Rxa6 26. Bh4 f6 27. exf6 gxf6 28. Bxf6) 22. dxe7 d5 23. e8=Q+ Bd7 24. Bb5+ Kc7 25. Bd6+ Bxd6 26. exd6+ Kb7 27. Bxd7+ Ka6 28. Qb5+ Ka7 29. Qc5+ Kb7 30. Bc6+ Nxc6 31. Qcxc6+ Ka7 32. Qcxa8+ Kb6 33. Qab8+ Ka5 34. Qa7+ Kb4 35. Qb6+ Kc4 36. Rc1+ Kd3 37. Nc5+ Kd4 38. Qxh8 f5 39. a4 e5 40. a5 e4 41. d7 e3 42. f3 f4 43. a6 e2 44. Qxg7+ Ke3 45. Qbh6 d4 46. b3 d3 47. g3?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. Qe6# was best. } (47. Qe6#) 47... d2# { Black wins by checkmate. } 0-1

```

https://lichess.org/HSvE0hLa

```
[Event "Casual Rapid game"]
[Site "https://lichess.org/HSvE0hLa"]
[Date "2022.05.31"]
[White "BortElGrasitas"]
[Black "forsenRage"]
[Result "0-1"]
[UTCDate "2022.05.31"]
[UTCTime "21:32:43"]
[WhiteElo "1500"]
[BlackElo "1972"]
[Variant "Standard"]
[TimeControl "720+3"]
[ECO "A33"]
[Opening "English Opening: Symmetrical Variation, Anti-Benoni Variation, Spielmann Defense"]
[Termination "Normal"]
[Annotator "lichess.org"]
[FEN ""]

1. c4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e6 { A33 English Opening: Symmetrical Variation, Anti-Benoni Variation, Spielmann Defense } 6. a3 Bc5 7. Nb3 Bb6 8. Na4 Bc7 9. g3 d5?! { (-0.58 → 0.06) Inaccuracy. Ne5 was best. } (9... Ne5 10. Qd4) 10. cxd5 Nxd5 11. Bg2 O-O 12. O-O b6 13. e4 Nde7 14. Qc2 Bb7 15. Rd1 Qc8 16. Be3 Be5?! { (0.45 → 1.27) Inaccuracy. Rd8 was best. } (16... Rd8 17. Nc3 Ba6 18. f4 Qb7 19. Bf2 Rac8 20. e5 Qb8 21. Be4 h6 22. Rac1 Rxd1+ 23. Rxd1) 17. f4 Bc7 18. Nc3 Rd8?! { (0.83 → 1.59) Inaccuracy. Qe8 was best. } (18... Qe8) 19. Nb5 Ba6 20. Rxd8+ Qxd8 21. Rd1 Qc8?! { (1.90 → 2.74) Inaccuracy. Qb8 was best. } (21... Qb8 22. Bf1 Bd8 23. Nd2 h6 24. b4 Bxb5 25. Bxb5 Qb7 26. Nc4 Bc7 27. Nd6 Bxd6 28. Rxd6) 22. a4?! { (2.74 → 1.79) Inaccuracy. Bf1 was best. } (22. Bf1) 22... Bxb5?! { (1.79 → 2.85) Inaccuracy. Bb7 was best. } (22... Bb7 23. Qd3 Rb8 24. Nd2 Ba8 25. Nc4 Qb7 26. Ncd6 Bxd6 27. Nxd6 Qd7 28. Nb5 Qc8 29. f5) 23. axb5 Na5? { (2.45 → 4.31) Mistake. Nb4 was best. } (23... Nb4 24. Qc3) 24. e5 Rb8 25. Nd4 Nd5?! { (4.12 → 6.43) Inaccuracy. Bd8 was best. } (25... Bd8 26. Nc6 Naxc6 27. bxc6 Bc7 28. b4 a6 29. Rd7 Ng6 30. h4 Nf8 31. Rd1 Qe8 32. Kh2) 26. Bxd5 exd5 27. b4 Nc4 28. Bf2 Bd8 29. Nc6 Rb7 30. Rxd5 f5 31. Rxd8+ Qxd8 32. Qxc4+ Kh8?! { (23.11 → Mate in 7) Checkmate is now unavoidable. Kf8 was best. } (32... Kf8 33. Nxd8) 33. Nxd8 Rd7 34. Nf7+ Kg8 35. Qc8+ Rd8 36. Qxd8+ Kxf7 37. Qd7+ Kf8 38. Qd6+ Kf7 39. e6+ Ke8 40. Qd7+ Kf8 41. e7+ Kf7 42. e8=Q+ Kf6 43. Qe5+ Kg6 44. Qee8+ Kf6 45. Qee7+ Kg6 46. Qde8+ Kh6 47. Q8f8 Kg6 48. Qff7+ Kh6 49. Qd6+ g6 50. Qde6 a6 51. bxa6 b5 52. Qfxf5 Kg7 53. Qfe5+ Kh6 54. f5 Kg5 55. f6+ Kh6 56. a7 g5 57. f7+ Kh5 58. f8=Q h6 59. Qc6 Kg4 60. Qd7+ Kh5 61. Qdf7+ Kg4 62. Qfe6+ Kh5 63. Q6d5 Kg6 64. Qeg7+ Kh5 65. a8=Q Kg4 66. Qgd7+ Kh5 67. Qab7 Kg6 68. Qbc6+ Kh5 69. Qdd8 Kg4 70. Qdc8+ Kh5 71. Q8c7 Kg4 72. Q6d7+ Kh5 73. Bd4 Kg6 74. Qd7c6+ Kh5 75. Qa5 Kg4 76. Qcd7+ Kh5 77. Kg2 Kg6 78. Qdg7+ Kh5 79. Qfh8 Kg4 80. Qgd7+ Kh5 81. Kh3 Kg6 82. Q7d6+ Kh5 83. Qg2?? { (Mate in 1 → Mate in 1) Lost forced checkmate sequence. g4# was best. } (83. g4#) 83... g4# { Black wins by checkmate. } 0-1

```

Technically this does not directly answer the question, but shows that trying to play for a loss has more depth than just playing the worst move suggested by a strong engine.
> 14 votes

# Answer
Yes, and the easiest strategy is to take all their pieces except a pawn, then attack all the squares around their king so only the pawn can move, and arrange for that to be a checkmate.

Example:

```
[FEN ""]
[White "Human"]
[Black "WorstFish"]
1. e3 { A00 Van't Kruijs Opening } b5? { (0.09 → 1.78) Mistake. Nf6 was best. } (1... Nf6 2. Nf3 c5 3. d4 d5 4. Be2 Nc6 5. O-O cxd4 6. exd4) 2. h4?? { (1.78 → 0.03) Blunder. Bxb5 was best. } (2. Bxb5 c6 3. Ba4 e6 4. Nf3 d5 5. d4 Bd6 6. c4 Ba6) 2... g5?? { (0.03 → 4.01) Blunder. a6 was best. } (2... a6 3. d4 Bb7 4. a4 b4 5. Nf3 Nf6 6. Nbd2 e6 7. Bd3 c5 8. e4 Nc6 9. e5) 3. Rh3?? { (4.01 → 0.40) Blunder. hxg5 was best. } (3. hxg5 a6 4. Nf3 Bb7 5. d4 e6 6. a4 b4 7. Bd3 h6 8. e4 Bg7 9. gxh6 Nxh6) 3... f5?? { (0.40 → Mate in 1) Checkmate is now unavoidable. g4 was best. } (3... g4 4. Rh1) 4. e4?? { (Mate in 1 → 0.82) Lost forced checkmate sequence. Qh5# was best. } (4. Qh5#) 4... h6?? { (0.82 → Mate in 1) Checkmate is now unavoidable. g4 was best. } (4... g4) 5. e5?? { (Mate in 1 → 0.43) Lost forced checkmate sequence. Qh5# was best. } (5. Qh5#) 5... Bb7?? { (0.43 → Mate in 1) Checkmate is now unavoidable. g4 was best. } (5... g4 6. Rb3) 6. hxg5?? { (Mate in 1 → 6.35) Lost forced checkmate sequence. Qh5# was best. } (6. Qh5#) 6... b4?? { (6.35 → Mate in 1) Checkmate is now unavoidable. Bg7 was best. } (6... Bg7) 7. Qf3?? { (Mate in 1 → -6.24) Lost forced checkmate sequence. Qh5# was best. } (7. Qh5#) 7... b3?? { (-6.24 → Mate in 1) Checkmate is now unavoidable. Bxf3 was best. } (7... Bxf3 8. Nxf3 Nc6 9. d4 e6 10. gxh6 Bxh6 11. Nbd2 Kf8 12. Bd3 a5 13. Nc4 a4 14. Kf1) 8. Qf4?? { (Mate in 1 → 2.28) Lost forced checkmate sequence. Qh5# was best. } (8. Qh5#) 8... Kf7?? { (2.28 → 16.43) Blunder. e6 was best. } (8... e6 9. Qg3) 9. Rxh6?? { (16.43 → -2.12) Blunder. Qxf5+ was best. } (9. Qxf5+ Nf6) 9... Bf3?? { (-2.12 → Mate in 4) Checkmate is now unavoidable. Nxh6 was best. } (9... Nxh6) 10. Nxf3? { (Mate in 4 → 7.97) Lost forced checkmate sequence. Qxf5+ was best. } (10. Qxf5+ Nf6 11. e6+ Kg8 12. Qg6+ Bg7 13. Qf7#) 10... c5? { (7.97 → Mate in 4) Checkmate is now unavoidable. Nxh6 was best. } (10... Nxh6 11. gxh6) 11. Rxh8?! { (Mate in 4 → 24.31) Lost forced checkmate sequence. Qxf5+ was best. } (11. Qxf5+ Nf6 12. e6+ Kg8 13. Qg6+ Bg7 14. Qf7#) 11... Kg7?! { (24.31 → Mate in 4) Checkmate is now unavoidable. Nh6 was best. } (11... Nh6 12. gxh6) 12. Rxg8+?! { (Mate in 4 → 13.74) Lost forced checkmate sequence. Qxf5 was best. } (12. Qxf5 Kxh8 13. Bd3 Nf6 14. exf6 exf6 15. Qh7#) 12... Kf7 13. Rxf8+ Ke6?! { (19.62 → Mate in 2) Checkmate is now unavoidable. Qxf8 was best. } (13... Qxf8 14. Qxf5+ Ke8 15. Qxf8+ Kxf8 16. axb3 Nc6 17. Nc3 Rc8 18. Ne4 Rc7 19. Bc4 Nd8 20. Ra5) 14. Rxd8 Nc6 15. Rb8?! { (Mate in 2 → 27.46) Lost forced checkmate sequence. Bc4+ was best. } (15. Bc4+ d5 16. Bxd5#) 15... Kd5?! { (27.46 → Mate in 1) Checkmate is now unavoidable. Rxb8 was best. } (15... Rxb8 16. Qc4+) 16. Rxa8 d6 17. Rxa7 c4 18. Rxe7 Nb8 19. Re6 c3 20. Rxd6+ Kc5 21. dxc3 Na6 22. Ke2 Nb8 23. axb3 Na6 24. Raxa6 Kb5 25. Ra8 Kc5 26. Rdd8 Kb5 27. e6 Kc6 28. e7 Kb7 29. g6 Kb6 30. g7 Kb5 31. e8=R Kc5 32. g8=R Kb6 33. Re7 Kc6 34. Rh7 Kb5 35. Rd6 Kc5 36. Rdh6 Kd5 37. Rh2 Ke6 38. R7h3 Kf6 39. Rae8 Kf7 40. Kd3 Kf6 41. Ke3 Kf7 42. Nd4 Kf6 43. Bd3 Kf7 44. Bd2 Kf6 45. Na3 Kf7 46. Nab5 Kf6 47. Na3 Kf7 48. b4 Kf6 49. b5 Kf7 50. b6 Kf6 51. b7 Kf7 52. b8=R Kf6 53. b4 Kf7 54. b5 Kf6 55. b6 Kf7 56. b7 Kf6 57. Ra8 Kf7 58. b8=R Kf6 59. Nab5 Kf7 60. Ra1 Kf6 61. f3 Kf7 62. Rf1 Kf6 63. Rf2 Kf7 64. Ra8 Kf6 65. Ra1 Kf7 66. Re1 Kf6 67. Ree2 Kf7 68. Na7 Kf6 69. Nc8 Kf7 70. Rd8 Kf6 71. Rd6+ Kf7 72. Rdd8 Kf6 73. Na7 Kf7 74. Rb8 Kf6 75. Nc8 Kf7 76. Ra8 Kf6 77. Ra1 Kf7 78. Ra7+ Kf6 79. Ra8 Kf7 80. Na7 Ke7 81. Rad8 Kf6 82. Nc8 Kf7 83. Rd7+ Kf6 84. Qe5+ Kxe5 85. Rg6?? { (Mate in 2 → Mate in 1) Lost forced checkmate sequence. f4+ was best. } (85. f4+ Kf6 86. Rh6#) 85... f4# { Black wins by checkmate. } 0-1

```
> 4 votes

# Answer
It's certainly possible, in fact a good player will probably succeed consistently. See Wiki on chess handicaps. One of the handicaps (and the one linked to above) is to force the opponent to checkmate you. This is a much bigger handicap than against worstfish, because humans will know what the win condition is (and try to avoid it), while worstfish will always react in a predictable way. You could put your queen *en prise*, and worstfish will never take it.

The general gameplan is to take all their pieces until they are practically paralyzed, then set up a self-mate.

This parody paper also contains a game which worstfish loses (see Fig. 8). Its opponent, playing random moves at the time, inadvertently played a move for which the only legal reply is a checkmate.
> 3 votes

---
Tags: engines
---


title: List of bad gambits?

text:
# Question
Title: List of bad gambits?
There are many good gambits, from tactical ones such as the Fried Liver Attack, the Evans Gambit, or the King's Gambit, to positional ones such as the Volga Gambit. But there are many bad gambits, such as The Omega Gambit(1.d4 Nf6 2.e4?) or gambits with one trap in mind, and nothing else (Blackburne-Shilling Gambit). Are there more of such gambits?

# Answer
latvian, halloween, wing, englund, elephant, freds, colorado, danish gambit, tennison, and budapest gambit of the top of my head. These gambits are unsound and a proper response will have the gambiter in a worse position.

Some gambits I do like are kings gambit, smith morra, evans, queens, scotch, benko, lisitsin, staunton, fried liver(Na5), froms.
> 4 votes

# Answer
I just want to save 2 gambits from being classified as "bad", the fried liver and the king's. 3 cooks fried an GM with the fried liver, the fried liver is +1.67, and the king's gambit's only "refutation" is the keene's defense, weakening the kingside (1.e4 e5 2.f4 Qh4+).

You could say the froms is good, but in fact, if white plays accurately, black would lose fast, analysis says the froms is +0.81. I accidently triped over an analysis of the omega gambit and it appears to be -0.66, while the kings is -0.79, so, you see, reputations isn't everything. There's another one, on my analysis board, the halloween is -0.59, see? The smith morra is not a great gambit with -0.21.

I just cannot understand the blackmar-diemer gambit, cause when theres an option to gambit a wing pawn, why gambit the center pawn? The 1.d4 d5 2.e4 is -0.97, and the 1.d4 d5 2.Nc3 Nf6 3.e4 is -0.72.

The old benoni is +0.88 if you don't accept the pawn, and the modern is +0.96 if you don't accept the sac. Apperantly the benko gambit is one of the most inaccurate gambit, it says +1.20, although it is good for human play. The Duras is +1.90 if black used it, so it's useless, the most inaccurate one is the traxler counterattack, which is +2.57 if black used it.
> 2 votes

# Answer
Firstly and i have decent chess experience so i can tell you. The fried liver with the knight sac on F7 Is borderline winning. For human play it mostly is, but technically black can POSSIBLY hold a draw. White is always better in this line, and for refutations like after E pawn takes the D pawn, and black moves the knight to A4, White gets a pawn up and is slightly better. Kings gambit Is simply worse but playable. Its about -0.5 so with correct play white should draw, though in human play white has chances. Danish while unsound at first is actually extremely suprising. its only -0.4 i believe being down to pawns. Saving line for black is NF6, after E pawn push, Black checks with the bishop on B5 i believe from memory, and your trying to exchange all the pieces. In an endgame its losing but as white if you know the theory its playable and very tricky. England Gambit is fairly bad, only two traps and black is just worse, Halloween gambit is truly terrible. I could go on with the lines but i shall make my definition. Good gambits include the italian gambit(Italian game and after sacrificing the center pawn your still not even worse its 0.0 with good chances), The Renowned Queens gambit(Obviously not really a gambit), Evans gambit, scotch gambit etc, and honestly ill put danish here cause white is worse but very playable. These all have in common that you get good compensation, good winning chances, etc. Trap gambits Is what it says, Englund gambit is an example, Or traxler(Traxler unlike Gotham says is truly awful, never play it). gambits like these hope to trap you and if you dont fall into it, Your opponent is simply much worse. And the lowest of the low are halloween gambit, latvian, Mosquito etc. They quite literally are just garbage
> 0 votes

---
Tags: gambits
---


# Question
Title: Using latex for Killer Chess Training homework club?
Killer chess training gives out worksheets like https://p8e5c7t2.rocketcdn.me/wp-content/uploads/2021/03/Friendly-Homework-23-%E2%80%93-2021-03-23.pdf every week.

They ask students to do three things:

1. Mark weaknesses with green squares (alternate: mark with circle)
2. Mark the worst placed piece(s) on both sides with yellow squares (alternate: mark with square)
3. Indicate the opponent’s idea with red arrows

Is there a latex package for marking up chess diagrams in this way?

# Answer
> 2 votes
There are multiple latex packages to produce chess boards (diagrams) most comprehensive is chessboard by Ulrike Fischer with numerous options (but it doesn't work with RTL languages). Start from there, everything you've described is in that package. if not satisfied try mpchess (works fine with RTL languages) Browse the documentation first the illustrations will show you what you need.

# Answer
> 2 votes
One option is to use the `xskak` package which loads and extends the `skak` package while also loading the `chessboard` package.

Overleaf has a great tutorial with examples, as well as links to examples in the documentation for the referenced packages. Works with both FEN and PGN notation.

Replacing `\showboard` with `\chessboard` will add a marker to the right of the diagram indicating if it is White to move or Black to move. Turn this off with `\chessboard[showmover=false]`.

**Additional features:**

### Example using `xskak`:

Be sure to include `\usepackage{xskak}` in the preamble.

```
% Example (works with both skak and xskak packages)
% Preamble
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[papersize={8.5in,11in},margin=1in]{geometry}
\usepackage{xskak}

% Document
\begin{document}

Figure~\ref{fig:startpos} shows the starting position.

\begin{figure}[h!]   % example use with figure
    \centering
    \newgame
    \chessboard % instead of \showboard
    \caption{Starting position for a game of chess.}
    \label{fig:startpos}
\end{figure}

For example White may choose to lead with the King's pawn fighting for central squares with \mainline{1. e4}.

Black responds with \mainline{1...e5} also seeking to grab central space.

Play proceeds with \mainline{2. Nf3 Nf6 3. Nxe5}.

\begin{center}
    \chessboard  % no need for LaTeX figure
\end{center}

% Showcase use of FEN
\newpage
\section*{Mate in 2}
\noindent Notes:  White to move.

\section*{Galitsky A}
\newgame
\fenboard{6R1/2pk4/8/8/4QK2/8/8/8 w - - 0 1}
\chessboard

\section*{Kolodnas Z}
\newgame
\fenboard{8/4P1Q1/3k4/8/3K4/8/8/8 w - - 0 1}
\chessboard[showmover=false]  % remove move indicator

\newpage
% Position source: https://lichess.org/wFLCholu
\chessboard[setfen=2rq1r1k/pb3pp1/1p6/b2PP3/3pB3/P7/1PQ2PPP/R1B2RK1 w - - 0 18,
            pgfstyle=border,
            markfields={h7,a5},
            color=blue!50,
            colorbackfield=b2,
            pgfstyle=color,
            opacity=0.5,
            color=red,
            markfield={a5},
            color=green,
            markfield={c2}]
\end{document}

```

### Output:

---
Tags: learning, diagram
---


# Question
Title: Is wearing headphones during chess games against the rules in FIDE and Chess.com?
Recently Vladimir Kramnik accused Hikaru Nakamura of cheating in online chess. He Tweeted : "It is impossible to imagine a player to be allowed to wear headphones during a game of chess." Or somethings along the lines of that. But is it actually illegal on chess.com? And also, are the FIDE rules forbidding it?

# Answer
> 6 votes
According to https://handbook.fide.com/files/handbook/OnlineChessRegulations.pdf

Rule 9.7 states that "Players are not allowed to have headphones in or over their ears during play."

I think that should clear any doubts in your mind. I have also personally played a couple of online chess events and I can definitely say that under no circumstances are you allowed to wear headphones during the match.

As in Hikaru's case, he is basically chess.com's main display man, so I can see why chess.com wouldn't mind him doing whatever he wants. You could say that chess.com literally doesn't care.

---
Tags: rules, fide, cheating, chess.com, nakamura
---


title: Chess Problem Database with PGN or FEN

text:
# Question
Title: Chess Problem Database with PGN or FEN
Is there a database of chess problems that have the game or positions PGN and or FEN?

# Answer
> 15 votes
Some large chess puzzle databases with links:

* Free open source collection of 1,743,871 Problems at chessblunders.org, collected from more than 6 million games from professional tournaments.. They have an API for access to database.
* Taken from the website "wtharvey":
* From the website "the art of mate in 2"

+ Nearly ~152000 puzzles in pgn format
    + You will also find four pgn files of ~ 500 puzzles made by "Argentine problemists"
* Browsable collection of problems at "Yet another chess problems database". There are ~420000 problems. Not sure whether it can be downloaded programmatically. In the "About" page, you will find more links, some of which are broken.

# Answer
> 6 votes
http://gorgonian.weebly.com/pgn.html

https://exeterchessclub.org.uk/downloads (in chessbase format)

Exeter chess club has many other valuable resources.

# Answer
> 3 votes
You can also buy Harold Van der Heidjen's endgame study database. It contains more or less all the endgame studies he could gather from the old classic (Saavedra, Ponziani etc..) to the most recent from every publications and composing tournaments out there. And everything in between (Troitsky, Rinck, Platov brothers, Kubbel, Kasparyan, etc..).

Back when I bought it in 2004 it contained 58000 chess endgame studies, but the most recent versions have most likely over 100k.

# Answer
> 2 votes
https://lichess.org/training it is a very good place for puzzles there are more than 2000000 in lichess you can download them from https://database.lichess.org/#puzzles and there are a lot of themes ex:-

# Answer
> 1 votes
If you don't mind playing on mobile, chesspuzzleblitz.com has a playable database and it lets you compete.

Also, chessbluders.org and www.yacpdb.org are great resources too.

# Answer
> 0 votes
The lichess puzzles are free to download and use, with FEN and annotation of themes, openings, ratings, ... However, they do not come as a pgn file, but as a csv file, so you need to process the file first if you intend to open it using a regular PGN viewing software.

---
Tags: problems, database, pgn, fen
---


# Question
Title: Understanding UCI Output of Chess Engine - how to get best continuation
I am trying to understand and parse the UCI (Universal Chess Interface) output of a chess engine (here Stockfish 15.1). Specifically, I calling Stockfish with the following command and want to get the best move, the best move continuation and stockfish's evaluation of the position (the score). For this, I call the engine with

1. position fen \<FEN\>
2. go movetime 100

In the following two examples of the output that I am getting from the engine. In the first example everything seems good. The last line gives me the best move and from the line before, I can take the score and the best continuation.

> info depth 1 seldepth 1 multipv 1 score cp -53 nodes 34 nps 34000 hashfull 0 tbhits 0 time 1 pv d7d6

> info depth 2 seldepth 2 multipv 1 score cp -53 nodes 68 nps 68000 hashfull 0 tbhits 0 time 1 pv d7d6 f1c4

> \[...\]

> info depth 13 seldepth 17 multipv 1 score cp -41 nodes 55000 nps 611111 hashfull 25 tbhits 0 time 90 pv d7d6 d2d4 e5d4 f1c4 f8e7 f3d4 g8f6 b1c3 e8g8 e1g1 g8h8 f1e1 b8c6

> info depth 14 seldepth 17 multipv 1 **score cp -41** nodes 62297 nps 604825 hashfull 28 tbhits 0 time 103 **pv d7d6 d2d4 e5d4 f1c4 f8e7 f3d4 g8f6 b1c3 e8g8 e1g1 g8h8 f1e1 b8c6**

> **bestmove d7d6 ponder d2d4**

However, in this second example, while the last line gives me the best move, the line beforehand does not give a full continuation as pv, but only the move "c7c6". This is not even the same move that is considered in the second to last line, so it seems that I cannot fall back to that line for the best continuation?

> info depth 1 seldepth 1 multipv 1 score cp -134 nodes 32 nps 32000 hashfull 0 tbhits 0 time 1 pv b8c6

> info depth 2 seldepth 2 multipv 1 score cp -122 nodes 73 nps 73000 hashfull 0 tbhits 0 time 1 pv c7c6

> \[...\]

> info depth 13 seldepth 16 multipv 1 score cp -141 nodes 36495 nps 598278 hashfull 12 tbhits 0 time 61 pv **b8c6** e1g1 d7d6 d2d4 g8e7 c1e3 e7g6 d4e5 d6e5

> info depth 14 seldepth 20 multipv 1 score cp -124 **lowerbound** nodes 61850 nps 612376 hashfull 26 tbhits 0 time 101 **pv c7c6**

> **bestmove c7c6 ponder b1c3**

Why does the engine give the output sometimes like this? It seems to mention "lowerbound" or "upperbound" in these cases? How do I get the best continuation pv from the engine in this case?

# Answer
> 1 votes
In that second example, the "lowerbound" indicates that Stockfish established that the position is at least a score of -124 centipawns, but it may actually be better. At depth 13, Stockfish determined b8c6 to be the best move. However, at depth 14, it found that c7c6 is better, but it was not able to complete the full search at this ply. There may be a different better move at this depth, but it was at least able to determine that c7c6 is at least better than b8c6.

This happened because Stockfish uses an Aspiration Search where it will assume that the correct evaluation for a move is within some pre-determined window (in this case, it would be some range around the evaluation from depth 13). This normally allows it to cut off a lot of moves early that fall outside of this narrow window. However, sometimes, it might find that there is a better move that lies outside of this window, so it needs to restart the search around some other window. In this case, Stockfish found that c7c6 was a better move that was outside of the upper bound of the window, meaning that it was able to establish the lowerbound for the score for this move. It reported that evaluation with the lowerbound score, but it wasn't able to finish the re-search in time to get the actual score, nor was it able to report the remaining moves in the principal variation.

Ultimately, the issue was that you are asking it to spend 100ms to perform the search, and that time elapsed after an inconvenient output. To get a better PV, you can try re-running the search for this position with more time, or you can run the search after making the recommended best move.

The big thing to remember is that Stockfish (and the UCI protocol in general) is ultimately built to play chess, so all that it really guarantees is that it will yield the best move after performing the search. Access to the full PV is just a bonus that is usually, though not always, available.

---

See Also:

---
Tags: engines, uci
---


# Question
Title: Games that are famous because of their underlying story
I would like this question to be Community Wiki because I hope to collect several answers.

Can you name famous games where part of the fame comes from the circumstances surrounding the game? I hope it is clear that this is not really a subjective question. Which games are selected will depend on people's preference, but for each answer it will be clear cut whether the game has a famous story or not.

To get the ball rolling, let me mention the following (if this question is liked, I will edit it to list all answers with, if possible, a link to the game):

* Tal - Benko, Belgrad 1959: Benko wore sunglasses to "avoid being hypnotized" by Tal.
* J. Polgar - W. Browne?: Polgar used to bring a teddy bear to the chess table. In this game, Browne (I think) took a toy cannon, aimed it at the bear, and started the game... which he won.
* Steinitz - Bardeleben, Hastings 1895: Steinitz's last move reached a position in which he had a forced mate in 10. Bardeleben left the tournament hall without finishing the game. Legend has it that he did not want to allow Steinitz the pleasure of reaching the mate, but it seems that he left because of noise and did let Steinitz know.

# Answer
> 10 votes
Bobby Fischer's games in the 1965 Capablanca Memorial gained fame because he was denied a visa to travel to Cuba, and was the only player in the tournament who had to play all of his games from New York by telephone. It was especially grueling because those games typically lasted 8 hours or more due to the communications lag.

# Answer
> 9 votes
There was a game involving Frank Marshall, in which he claimed his last move excited the spectators in such a way, they showered him with golden coins. However, I've also read the coins were not intended for him, but tossed on the table by those who bet against him, for the winning gamblers to collect. But it was an amazing move though.

More info here:
https://www.chesshistory.com/winter/extra/marshall1.html

# Answer
> 8 votes
Game two of the Fischer-Spassky world championship in 1972 comes to mind. Fischer forfeited it because of the cameras in the main hall. Due to Fischer's theatrics, Spassky agreed to play the 3rd game away from the audience, and lost. Then the drama by the Soviets around "devices" allegedly placed in Fischer's chair designed to disrupt Spassky's thinking.

The entire Karpov-Korchnoi world championship match of '78 was wrapped in oddness including a Russian "psychic" whose image graced the cover of (then) Chess Life and Review. The Soviets sent the "psychic" strictly to unnerve Korchnoi who apparently believes in such things. Florencio Campomanes, future president of FIDE, allowed the psychic to sit in the first row, even after it was agreed he would not. Then there was the yogurt scandal, where the Soviet support staff sent the snack to Karpov without Karpov asking, raising protests from Korchnoi's team since the timing and type of yogurt could have been a coded message. Ah, and also Campomanes allowed Karpov an unscheduled break in the tournament so he could rest.

# Answer
> 8 votes
Albert Einstein vs Robert Oppenheimer \- Einstein won obviously :)

Neither of them was a professional chess player, but the game is so famous, simply because everyone wants to see Einstein playing chess!

# Answer
> 3 votes
Games 2 and 6 of the Kasparov-Deep Blue rematch in 1997 would be good candidates because of the controversy surrounding those games and the match in general.

Unfortunately, I don't have a good link handy and Wikipedia is rather bare.

# Answer
> 1 votes
Do clearly fictive games count? One word: Mate of Dilaram. (A very old Mansuba - chess problem - by As-Suli. This works because Mansubas were very game-like. A prince bets his favorite harem dame since he already lost everything else, and just as he is about to be mated, she prompts him the hidden win. Of course nothing of the story is acceptable by todays standards - especially the cheating part.)

# Answer
> 1 votes
How GM Bernstein saved his life from the Sovjet Secret Service by game of a chess: From third hard, so perhaps apocryphal.

---
Tags: history, famous-players, famous-games, famous-events
---


# Question
Title: What are some of the present and past GM known to be autistic?
As an Asperger player, I played from 5 to 10. I won at school and at regional tournaments. I left it

I returned at 18. I spent 15 years playing online and OTB (a lot of daily hours).

My best:

* 2900 in chess.com tactics trainer.
* 1950 in rapids (playing 15' games in french Federation).
* 1750 in slow games at Spanish FEDA.

I have books but I do not read them. I get bored because I do not understand what they say and I have never tried seriously to study theory. I am not good evaluating positions either. I failed many times to match with Stockfish evaluation. Reading here what a master thinks at a position was the definitive read when I knew that was impossible to me. Even I hadn't left chess at 10 I do not think I would have reached more than 2000.

I find I have some kind of limitation in my brain. I only won 1700 because of tactical mistakes and because I know a bit how to enter in won endgames.

I am curious if other autistic players succeeded to "decrypt" chess. Maybe GM Julio Granda is a clear case (related)?

# Answer
I am also neurodiverse and have written a book about that (and a second one is almost done). I play chess badly but I enjoy it.

I think there are going to be two big issues in answering this question. First, you have to define exactly what you mean by "neurodiverse". This term is relatively new and the meaning is somewhat in flux. Second, you have "known to be". That would indicate you want a list of people who have been diagnosed with something, and are open about it. But a lot of neurodiverse people either a) Don't have an official DX (diagnosis) or b) Aren't open about it.

It's still hard to get a DX (and much harder in some places than others), and there is still a lot of stigma (more in some places than others).

It's tempting, but dangerous, to diagnose from afar and based only on what we read. Was Bobby Fischer neurodiverse? It sure seems like it, but I doubt he was ever tested.
> 3 votes

---
Tags: psychology, grandmaster
---


# Question
Title: How to challenge a queen with a bishop pair in endgame?
Any hints how to survive or win having a bishop pair against a Queen in endgames. What you should do? how to cooperate between them? what's the opponent best strategies?

# Answer
This is one of the well known endgames and the side with the queen almost always (92% positions) wins, although some wins take more than 50 moves with perfect play.

See the solution for your position here by entering your position into the diagram.

I must point out that **every** move has been taken into account and **every** possible continuation has been explored.

I forgot to answer part of your question about challenging the queen:

* with best play side with the bishop loses most of the time, as stated above;
* side with the bishops can **never** win, due to reasons user *ETD* pointed out in his comment;
* in order to defend vs queen, use bishops to create barrier for the enemy king; keep them close to your king in order to be safe from double attacks queen can make.

It is worth noting, that the position shifted down by one row is a fortress setup and black draws. The setup is known as the Lolli position.

```
8/6k1/5bb1/8/2Q5/8/3K4/8 w - - 0 1

```
> 13 votes

# Answer
It is winning for white, because queen and king can bring black into zugzwang, where black loses bishop. I tried it against stockfish and I won it, but it takes 56 moves.
> 0 votes

# Answer
This looks like a very simple draw. Shuffle the bishop from g7 to f8 to g7 and if that is illegal shuffle the king one square back and forth while protecting both of the bishops.
> -1 votes

---
Tags: endgame, bishop-pair, queen-and-bishop-endgame
---


title: How early can you resign a game?

text:
# Question
Title: How early can you resign a game?
Imagine a situation where you are playing in a FIDE-rated tournament.

You're at the board but for some reason you don't want to play anymore.

Can you resign the game before it even starts, or can you resign after the first move of the game is played?

# Answer
> 6 votes
> Can you resign the game before it even starts, or can you resign after the first move of the game is played?

Strictly speaking you can resign at any time the game is in progress. The practical implication of this is that, unless there is no series of legal moves whereby your opponent can deliver checkmate, you lose and your opponent wins.

For rating purposes the game is not viewed as "started" until each side has played one move. Hence the earliest you can resign is after one move.

If you just don't want to play the game the best course of action is to tell the arbiter beforehand that you are withdrawing. You can say "for personal reasons" and you don't have to go into detail. If you want to continue in the tournament, just not play that game, then again go to the arbiter and tell them you had a phone call from home, you are very sorry, but you have to go back to sort it out or just take some time out to sort it out if you live a long way away.

The next best course of action would be to phone default. Have your phone with you and switched on and arrange for a friend to call you just after the game starts.

All other courses of action, including resigning after one move, have bad consequences for you.

1. If you play one move and resign then you will come under suspicion of collusion with your opponent. Depending on how strict the organisers are you may end up anywhere from being thrown out of the tournament to banned for life from that tournament in future years.
2. You could just not turn up for the game.The question will be asked, "Why didn't you tell the arbiter?" This could affect your entry to the tournament in future years or any tournament where the same organisers or arbiters are involved.

# Answer
> 2 votes
The worst possible way to end is legally play one move and then resign. A non-fair word for this is 'sandbagging'. If you do this then you can get caught for cheating since this increases the rating of your opponent and gives him/her a point intentionally.

The next possible way is to just tell the officials or your arbiter that you don't want to play with a valid reason.

FIDE rules and regulations against cheating

In conclusion; no, you can't resign a game without it actually starting.

---
Tags: rules, fide, resigning
---


title: What are the middle game principles?

text:
# Question
Title: What are the middle game principles?
What are the middle game principles? I have already seen numerous principles regarding the opening and ending, but not the middle.

# Answer
1 - Centralize and coordinate your pieces. This is when tactical opportunities will begin to materialize.

2 - When your position is cramped, exchange pieces.

3 - When ahead in material, exchange pieces, not pawns.

4 - When you have a bad or inactive piece, exchange it.

5 - Don't launch an attack on the flank until the centre is secure.

6 - When the opponent's king is exposed, look for tactics and combinations.

7 - When the opponent's development is poor, look for tactics and combinations.

8 - Attack your opponent's weak and backwards pawns.

9 - Occupy your opponent's weak squares. Knights are particularly good at establishing outposts.

10 - Don't make unnecessary pawn moves in front of your king. This weakens your position.
> 7 votes

# Answer
"When looking for tactics - for either player - look for Checks, Captures, and Threats, in that order - for both players."

\*"If you are winning by a piece or more, THINK DEFENSE FIRST. That does not mean play passively."

"The Exchange (winning a rook for a bishop or a knight) is worth about half of a piece."

\*"If you are interested in learning, think of a draw offer as an offer to remain ignorant!"

"Putting out your hand when you offer a draw is presumptuous; always put it out after the draw is agreed upon, not before."

"If you get way ahead, it is more important to use all your pieces and safeguard your King than it is to try and get further ahead."

"Most games between lower rated players are won or could be won on tactics, so studying tactics when you are lower rated is much more important than anything else."

"Attack pinned pieces with pieces worth less than them; never take a pinned piece unless it leads to some sort of tactic or you cannot maintain the pin."

"Having the 'Bishop Pair' - two Bishops when your opponent does not - is worth about half a pawn."

"Bishops are better in open positions - Knights are better in locked/closed positions - Bishops are also better when there is action on both sides of the board."

"When ahead pieces trade pieces, when behind pieces, trade pawns."

"If you have a pair of Rooks and your opponent only has one, it is usually correct to trade Rooks."

"Knights are 'Path' pieces. Have an idea of where you want one to go!"

"Patzer sees a check - gives a check," but "Always (consider) a check, it might be mate."

"Doubled pawns are not always weak."

"When capturing with pawns, it is correct most of the time to capture toward the center. If the result is doubled pawns, this is correct even a higher percentage of the time." It is also more likely correct when capturing on a Knight file (b or g).

"A premature attack is doomed to failure."

"You can't attack where you don't have an advantage."

"An attack on the flank is met by a counterattack in the center." Especially if the center is not fixed/stable.

"Rooks need open and semi-open files. Don't let your opponent control open files with his Rooks."

"Don't 'give up' control of an open file by trading Rooks and bringing your opponent's other Rook to the file unless you can either neutralize the file by moving a Rook/Queen to that file or have some tactic."

\*"It is not enough to recognize tactics. You must recognize them quickly enough that you will see them - even without prior knowledge that they are there - during the short time you have to move in a normal game"

"If the four e and d pawns are all locked together, then the 'pointing rule' says 'put your hand across your d and e pawns so that it points toward your opponent (the other way hurts your hand!); whichever side of the board your hand is pointing is the side you should attack - and also the side you should play the pawn break on the c or f files'" Note: Don't apply this guideline unless all four pawns are locked against each other!

"When the game gets complicated and there are a lot of captures, it is usually correct to make a capture (or at least an extremely strong threat) to hold the initiative. To make a quiet move usually leaves your opponent the opportunity to take the initiative." In any case, specific analysis and not general principles are required to make the decision!

"If you have some sort of structural or minor material deficit, it is better not to trade and to play aggressively, or else your opponent's long-term advantage will tell in the late middlegame and endgame."

"When both Kings are exposed and the heavy pieces are still on the board, the initiative (or attack) is often worth everything – so you usually should keep checking (or capturing) if you can." In these positions sacrifices of material are often quite common as you cannot let your opponent start attacking with tempo.

"Talk to your pieces. See which ones have the best arguments for moving them next. Never ignore a piece completely!"

"When your opponent has weak pawns, trade a few pieces. Then the weakness of the pawns often becomes easier to exploit."

\*"If a piece is attacked defended, but some of its defenders are removable, then you can't count them as defenders - so that piece may be possibly won with removal of the guard!"

When you have several checks, consider first:

Checks that bring additional pieces into the attack, or

Checks that bring a powerful piece (like the Queen) closer to the King to guard more squares.

"Material doesn't mean as much if you castle opposite sides and queens are on the board."

Attack pinned pieces with more pieces, especially pieces worth less than the pinned piece.

In complicated positions with multiple capturing possibilities for both sides, it is usually correct to make the first capture, if possible.

The worst types of pawns are vulnerable pawns (backward, isolated, etc.) on semi-open files. Alternatively, doubled pawns can sometimes be strong, so don't count all non-perfect pawn structures as "bad".

It is almost always worse to lose a pawn than to take on a pawn weakness.

When creating luft to prevent back-rank mates against an opponent with one bishop, clear the square the opposite color of the bishop

There are two types of sacrifices:

Those in which the sacrificer does not capture material. These sacrifices you can take or not, depending upon which is better.

Those in which the sacrificer captures material. These sacrifices you almost always must accept/capture if your opponent's previous capture puts you behind in material, because you will lose anyway. Obviously if you see a mate in three and otherwise you lose a pawn, you lose the pawn, but most times you just capture. For example, you almost always capture the classical bishop sacrifice Bxh7+.

When your opponent has a pawn, bishop, or knight on "knight 3" (b3/g3 for White and b6/g6 for Black) then it is often a possible plan to attack it with a pawn, usually R4-R5 (a5/a4 or h5/h4 for Black or a4/a5 or h4/5 for White), possibly B4-B5 (c5/c4 or f5/f4 or c4/c5 or f4/f5)

If one side is weak on a particular color complex, the other side has a bishop of that color, and the side with the weak squares does not have that color bishop, then that is a large advantage for the side with the bishop, and even larger (possibly a pawn or more) if queens are still on the board and there are lots of pawns.

SOURCE
> 5 votes

# Answer
In the middle game, you are seeking an advantage that will win you the game. This could take the form of 1) an attack against the enemy king 2) the gain of a pawn (or more) of material or 3) a positional advantage that will win you the end game, such as a rook on the "seventh" rank (second for Black) a knight in a "hole in d5, d6, e5 or e6 (d4,d4,e4, or e3 for Black), a "good" bshsop vs. a "bad" bishop, a "passed" pawn, or a weakness in the opponent's pawn structure such as a doubled or isolated pawn.
> 1 votes

# Answer
In *A First Book of Morphy*, Frisco Del Rosario presents principles from Reuben Fine and Cecil John Seddon Purdy for the opening, middlegame, and endgame, along with accompanying annotated games from Paul Morphy to illustrate the principles.

The middle game principles are listed below.

**Middle Game Principles:**

1. Have all your moves fit into a definite plan.
2. When are material ahead, exchange as many pieces as possible, especially queens.
3. Avoid doubled, isolated, and backward pawns.
4. In cramped positions, free yourself by exchanging.
5. Don't expose your king while the enemy queen is still on the board.
6. All combinations are based on a double attack.
7. When your opponent has one or more pieces exposed, look for a combination.
8. To attack the enemy king, you must first open a file (or less often a diagonal) to gain access for your heavy pieces.
9. Centralize the action of all your pieces.
10. The best defense is a counterattack.

Reference:
Del Rosario, F. 2004. *A First Book of Morphy*, Trafford Publishing, p. 78
> 1 votes

# Answer
The middle game in chess is a pivotal phase where players transition from the opening to the endgame. It's characterized by maneuvering, development, and strategic planning. Here are key principles to excel in the middle game:

**Development:** Complete your development by getting all your pieces into active positions. Aim to control the center, deploy your knights and bishops effectively, and castle to safeguard your king. Rapid development ensures your pieces are ready for active play and contributes to a strong middle game.

**King Safety:** While kings are relatively safer after castling, assess potential threats to your king's safety continually. Maintain pawn cover in front of your king and avoid weakening your pawn structure unnecessarily, as it could create weaknesses attackers might exploit.

**Control the Center:** Dominating the center provides greater mobility for your pieces and control over key squares. Use pawns and pieces to exert influence over the central squares (d4, d5, e4, e5). This control often translates into a more significant advantage and opportunities for launching attacks.

**Piece Activity:** Ensure your pieces are active and coordinated. Avoid leaving any piece inactive or poorly placed. Plan to improve the positions of your less active pieces by repositioning them to better squares where they exert more influence.

**Pawn Structure:** Assess and manage your pawn structure wisely. Avoid creating isolated or doubled pawns if possible. Maintaining a healthy pawn structure supports your pieces' mobility and creates fewer weaknesses for your opponent to exploit.

**Plan and Flexibility:** Formulate a plan based on the position's features: weak squares, potential targets, or a pawn break. However, stay flexible and ready to adjust your strategy based on your opponent's moves or changing dynamics on the board.

**Tactical Awareness:** Stay vigilant for tactical opportunities, such as forks, pins, skewers, and discovered attacks. These tactical motifs can swiftly change the course of the game in your favor if executed accurately.

**Coordination and Harmony:** Aim for coordination among your pieces, ensuring they work harmoniously towards your strategic goals. Pieces supporting each other create threats that your opponent must address, increasing the pressure on their position.
> 1 votes

---
Tags: learning, middlegame
---


# Question
Title: When playing "Play with a friend" anonymously on Lichess with "Real Time" time control, does minutes per side get carried over?
Does the remaining part of "x minutes per side" get carried over if a side does a move in less than x minutes? i.e. if it's 3 minutes per side & I finish a move in 1 minute, will my remaining 2 minutes get carried over to the next move - i.e. will I get 5 minutes for the next move?

I want to create a game where each move gets completed in max 'x' minutes - is there a way to do that. Also, I am not sure how the "increment" affects this but I guess I can set it 0 so it doesn't.

# Answer
The time is *total*, so for the whole *game*, not per move. If you run out, you lose (or, if the opponent has only a bare king or similar, it's occassionally a draw).

After each move, the "increment" gets added to the time. So when you run really low on time, you'll at least have that many seconds per move.

So yes, it gets carried over. You can create a "1 minute per move" game by setting the initial time to 1 minute and increment to 60 seconds, but if people move faster then they will have longer for the next move.

This is called a "Fischer" increment, it was his invention. What you want is called "Bronstein" time delay. Unfortunately I've never seen an online chess site that implements that, it's always Fischer style.
> 2 votes

---
Tags: time-control, lichess
---


# Question
Title: Game vs. Stockfish, not sure what I did wrong
```
[FEN ""]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qd6 4. Be2 Nc6 5. Nf3 e5 6. d4 Nxd4 7. Nxd4 Qxd4 8. Qxd4 exd4 9. Nb5 Bd6 10. Nxd6+ cxd6 11. Bf4 Bf5 12. O-O-O Rc8 13. c3 dxc3 14. Bb5+ Kf8 15. Bxd6+ Ne7 16. Rhe1 Be6 17. Bd7 cxb2+ 18. Kxb2 Re8 19. Bxe8 Kxe8 20. f4 g6 21. Be5 Rg8 22. Bf6 Nc6 23. Rd6 Kf8 24. Red1 Bd5 25. R1xd5 a6 26. Rd8+ Nxd8 27. Rxd8# null 28. Rxf8# null 29. Rxg8# null

```

In case you didn't guess from the winner, Stockfish was white and I was playing black. Also, I gave myself 10 minutes for the whole game, with no increment. I technically know what mistakes I made but would like some practical advice on how to actually avoid them while I'm playing; engine analysis can show you the lines after the game but that doesn't really help you improve that much as a chess player.

# Answer
> 2 votes
Well, stockfish is too strong that Carlsen can't even compare, so don't worry.

In my opinion, before e5 you should calculate the variations with d4 and Nb5, and they did bring u problems.

Bd6 is really not a good choice. Black gave up his bishops. After the exchange on d6, white owns bishop pairs in a really open game, and the pawns on d-line are really weak.

Kd8 may get stuck by Bf4, but Bb4+ and Ba5 is great. Take the chance that white king in e1, and you can get a free move. if white Bd2, then Kd8 after the exchange is safe because there's no Bf4.

After the exchange on d6, stockfish just showed its extraordinary skills.

In the end: that's all my own opinions, and I checked it on stockfish before write the things above. I got fide rating 2000+.

# Answer
> 0 votes
...Bd6 leads to catastrophic pawn weaknesses and loss of the Bishop pair. But as that looks unavoidable without other concessions your mistake is earlier. After 6.d4 you probably should play 6...a6 to stop Nb5.

Your position is still bad as you are well behind in development. 5...e5 looks too ambitious and you probably should have gone for Bg4 or Bc5 instead.

---
Tags: strategy
---


title: Chess fever (literarily)

text:
# Question
Title: Chess fever (literarily)
Has someone tested how it is to play chess under the flu? (Perhaps online, as you don't want to infect the whole room.) I claim that with 40° fever, the only effect is that my brain processes speed up by a factor of whatnot (anyone care to apply the Arrhenius equation with typical values?). Of course headaches, bodyaches and shivering are a tad distracting, but I went to an important cup game with a sepsis fever, won epically and *then* got me some antibiotica. (Recommendation: Don't try this at home. I'm a complete wacko with a super immune system...)

Thus: Do brain processes really speed up under fever? (Death panic - this *was* tested with a drop tower - gives the illusion but doesn't work. Same methodology - speeding digits - could be done with fever, minus the drop.)

# Answer
> 2 votes
Your intuition is correct, according to biophysical models:

For instance, this paper states:

> In this study, we focus on the influence of temperature on neuronal behavior including variations in firing rates as well as in firing patterns. Using a biophysical neuronal model we show that neurons subject to higher temperatures produce short duration spikes capable of recovering more quickly, passing their refractory period, and becoming ready for another spike. This allows the cell membrane to reach the threshold of firing for a faster generation of another action potential, making the neuron operate at a higher firing rate.

You should try playing lots of short matches against a computer opponent, and record your stats. Then when you feel better, you can try to beat them. Let us know how it goes.

---
Tags: psychology, blitz, reference-request, studies-published-report
---


# Question
Title: Missing move in a chess match due to lousy annotation
I am a beginner in championships (well, and in chess in general). The other day I played a match that I can't analyze because there is an error in the annotation sheet.

```
[FEN ""]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bc4 d5 5. Bb3 Nf6 6. d4 Bg4 7. O-O Nxe4 8. dxe5 Bxf3 9. Qxf3 Nxe5 10. Qd1 c6 11. Nc3 Bc5 12. Nxe4 dxe4 13. Qxd8+ Rxd8 14. Ba4 O-O 15. b3 Ng4 16. Bg5 Rd2 17. Bxd2 b5 18. Be3 Nxe3 19. fxe3 Bxe3+ 20. Kh1 f5 21. b4 bxa4 22. Rfd1 f4 23. Rd6 f3 24. Re1 f2 25. Rf1 Rc8 26. g4 c5 27. Rxa6 cxb4 28. Rxa4 Rxc2 29. Rxb4 Rxa2 30. Rxe4 Re2 31. h4 Re1 32. Kg2 null 33. Rxe3 Ra1 34. Ra2 Ra5 35. h5 h6 36. Ke4 Rg6 37. Kf6 Kh7 38. Re6 Ra5 etc.

```

I have Black's 32nd move recorded as Rf2, but that is wrong. Is it possible to fix this?

\[Update\] I uploaded scans of the match. It's in Spanish meaning that

* C is Knight
* A is Bishop
* R is King (which made me commit mistakes for rook)
* T is Rook
* D is Queen

# Answer
> 1 votes
This is a tough one. If the move was 32...Re2 (perhaps making 33...Ra1 a wrongly notated move which was replaced by the correct Ra2), then I question why you didn't play 33...Rxe3. But if it was anything else, then I question why White wouldn't play 34.Rxa1.

So I think there were multiple missed moves at this spot in the notation. For example, maybe this was played:

```
[FEN ""]
[startply "63"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bc4 d5 5. Bb3 Nf6 6. d4 Bg4 7. O-O Nxe4 8. dxe5 Bxf3 9. Qxf3 Nxe5 10. Qd1 c6 11. Nc3 Bc5 12. Nxe4 dxe4 13. Qxd8+ Rxd8 14. Ba4 O-O 15. b3 Ng4 16. Bg5 Rd2 17. Bxd2 b5 18. Be3 Nxe3 19. fxe3 Bxe3+ 20. Kh1 f5 21. b4 bxa4 22. Rfd1 f4 23. Rd6 f3 24. Re1 f2 25. Rf1 Rc8 26. g4 c5 27. Rxa6 cxb4 28. Rxa4 Rxc2 29. Rxb4 Rxa2 30. Rxe4 Re2 31. h4 Re1 32. Kg2 Re2 33. Kf3 Ra2 34. Rxe3

```

After all, we know a Kf3 was likely missed, because there's a later Ke4 and the king had to get there somehow. Ultimately you're the one who played the game; see if that rings a bell in your memory as something which might have happened.

# Answer
> 1 votes
Judging by how the game continues, I think the White rook f1 must have been captured around this time. That leads me to believe that rook f2 was in fact rook takes f1, taking off that rook. There are some irregularities in the moves that follow, however, I think this may have been the sequence of moves, consistent with the remaining moves later:

```
[FEN ""]
[startply "63"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bc4 d5 5. Bb3 Nf6 6. d4 Bg4 7. O-O Nxe4 8. dxe5 Bxf3 9. Qxf3 Nxe5 10. Qd1 c6 11. Nc3 Bc5 12. Nxe4 dxe4 13. Qxd8+ Rxd8 14. Ba4 O-O 15. b3 Ng4 16. Bg5 Rd2 17. Bxd2 b5 18. Be3 Nxe3 19. fxe3 Bxe3+ 20. Kh1 f5 21. b4 bxa4 22. Rfd1 f4 23. Rd6 f3 24. Re1 f2 25. Rf1 Rc8 26. g4 c5 27. Rxa6 cxb4 28. Rxa4 Rxc2 29. Rxb4 Rxa2 30. Rxe4 Re2 31. h4 Re1 32. Kg2 Rxf1 33. Rxe3 Ra1 34. Kxf2 Ra2+ 35. Kf3 Ra5 36. h5 h6 37. Ke4 Rg5 38. Kf4 Kh7 39. Re6 Ra5 40. Ke4 Ra4+ 41. Ke5 Rxg4

```

---
Tags: retrograde-analysis
---


# Question
Title: Lichess's Browser Engine vs. local Stockfish
I often come across chess commentary mentioning phrases like "this is just a weak browser engine, let's see what the proper engine says." As far as I understand, Lichess's browser engine is essentially the same as Stockfish, albeit potentially slightly slower due to browser architecture.

Can someone confirm if my understanding is accurate? I'd like to know if Lichess's in-browser Stockfish is indeed similar to the standalone version (given versions are the same), or if there are notable differences that might justify these comments in chess commentary.

# Answer
Your understanding is accurate, but generally, the online engines limit the "depth" that the engine can go. The "depth" used to refer to ply, but with NNUE engines, it does not really map to that anymore. When I really want to see what's going on, I will bring the position down to my local instance of SF16, put 32 cores against it and let it run for a long time. It can generally reach "depth" of 45-50 in many positions. That's a much "better" evaluation than the limit of "depth" 20 that most online engines will go. However, you can easily use a tool like Chessify to reach very high "depths" and then it's really equivalent.

More in-depth (hehe) discussion of depth.
> 4 votes

---
Tags: stockfish
---


title: How to detect an illegal position?

text:
# Question
Title: How to detect an illegal position?
There are many positions in chess that are illegal in the sense that they cannot be reached by legal moves.

Is there an algorithm to detect if a position is illegal or not?

# Answer
Not really, or, at least, nothing that is of practical value.

You could, in theory, play the game backwards. If no branch reaches the initial position you have shown it is 'illegal'. This is mainly a chess problem area: for more info see https://en.wikipedia.org/wiki/Proof\_game. There is also software for proof games, but, as all software, limited (see https://en.wikipedia.org/wiki/Software\_for\_handling\_chess\_problems).

The problem area of retroanalysis (which typically only regards less specific questions than full proof games) touches on your question. (See https://en.wikipedia.org/wiki/Retrograde\_analysis), and some of the ideas from that field can be used to identify some illegal positions, but can't necessarily cover all of them.

So: no algorithm for illegal positions. For legal positions an algorithm can be formulated (see proof games above), but can't necessarily be implemented to perform in a period of time that is practical for humans.

A closely related question was asked in: Are there any illegal positions that are difficult to spot? and many of the example positions may add further light.
> 1 votes

# Answer
Well, you could generate all possible positions, and draw arrows between two positions A and B, if B can be reached from A in a single move.

Then use Dijkstra to see whether there is a finite-length path between the starting position, and the position you want to determine whether it is illegal or not.

But that's just a theoretical exercise. The shear amount of possible positions makes this unfeasible to use this in practice.
> 0 votes

---
Tags: illegal-move
---


title: What are "Jamboree chess pairings"?

text:
# Question
Title: What are "Jamboree chess pairings"?
Following on from this question, what are "Jamboree chess pairings"? That is the first time I have heard of them.

# Answer
> 2 votes
From what I can gather, a Jamboree tournament is a team tournament with fixed pairings (that is, they will not change based on results like a Swiss.) Unlike a typical team tournament, there is no one opponent that a team will face in a particular round.

For example, in a 2 round tournament with 3 teams, in round 1 team A might have their board 1 play against a player from team B, while their boards 2 and 3 play against players from team C.

---
Tags: tournament, jamboree, pairing
---


# Question
Title: Where can one find a complete chess curriculum?
Has anyone ever produced a complete chess curriculum? E.g., with textbooks, learning objectives, comprehensive syllabus, test bank, quizzes, etc.

# Answer
> 20 votes
The closest thing to this is a series of books by Russian-born German GM Artur Yusupov. This is what Yusupov wrote in the introduction:

> In 2004 I began a 3 year training programme in my chess academy. Three groups were set up according to playing strength: under 1500 Elo, under 1800 Elo and under 2100 Elo. Each annual stage consisted of 24 teaching modules and 24 tests, plus a final test at the end of the course.
> ...
> The overwhelmingly positive comments of my students encouraged me to rework this programme in the form of a series of books.

There are three sets of 3 books each set of books corresponding to one of the three groups of students. The three sets are colour-coded and called:

1. Fundamentals (orange-brown)
2. Beyond the Basics (blue)
3. Mastery (green)

He later published a 10th book, *Revision & Exam 1: The Fundamentals (Yusupov's Chess School)*. Despite the title and the colour (orange-brown) it is more advanced and should probably be green.

# Answer
> 20 votes
In addition to the Yusupov series, another complete curriculum is the **Chess Steps** series. It is the official method of the Royal Dutch Chess Federation (source) and comes recommended by The Perpetual Chess Podcast.

The six-step series is designed to take someone from zero skill and build to 2100 FIDE strength. You can review the themes in each Step at the English version of the Dutch site.

The Chess Steps:

1. Rating up to 800
2. Rating up to 1400
3. Rating up to 1600
4. Rating up to 1750
5. Rating up to 1900
6. Rating up to 2100

Solving 80+% of the exercises correctly is the recommended minimum prerequisite to advance a step (source).

**Materials.** The materials include a manual for each step, along with workbooks of different types.

The Workbooks **Basic** and **Plus** have problems matching the lessons of the **Manual**. Workbook **Extra** repeats the subjects of workbook **Basic** and can be used for extra training. Workbook **Mix** is one big test to see if a student can implement the learned knowledge when no subject is given and is more similar to real game situations.

**Discussion.** The Yusupov books are excellent as they also target well-rounded skills in the progression (similar to the Chess Steps). One key difference is the first Yusupov book is considerably more difficult than Step 1.

Additional References:
Review of the Chess Steps Method
Chess Master Han Schut on how to gain rating points into your 50s + using the "Chess Steps Method"

# Answer
> 3 votes
If you're looking for free online resources, have a look at https://www.chessfactor.com/ . There are complete learning paths including lectures, puzzles and so on that are designed to take you from learning the rules to 1800+ Elo.

At each level, the titled chess coaches selected the right mix of opening, middlegame and endgame knowledge that is required to push you to the next level (i.e. playing strength).

Even world-class GMs like Sam Shankland made lectures for their platform. It's definitely worth checking them out, completely for free (donation-based).

# Answer
> 0 votes
Also worth noticing is the series by Max Euwe "Praktische Schaaklessen". They are in Dutch

1. **Part 1 - From home chess player to club chess player**: This book covers the rules and principles of the game, explained with common twists from practice.
2. **Part 2 - General tips for opening, middle game and end game:** This book provides an overview of the game characteristics that form the basis for assessing moves and positions.
3. **Part 3 - Opening Repertoire:** This book covers the opening phase from the perspective of both white and black.
4. **Part 4 - Theoretical and practical endgames:** This book is about mating, theoretical and practical endgames in common material relationships.
5. **Part 5 - Judgement and Planning:** The Strategy of Chess: This book covers position types and the conclusions that should be drawn from them.
6. **Part 6 - Advanced Endgame:** This book provides insight into virtually all emerging developments and possibilities of the endgame.

---
Tags: learning, training
---


# Question
Title: Mate in 2 from "The soviet Chess Primer" but wrong
I found this exercise on page 51 of the "The soviet chess primer" and I think there is a mistake. Chess.com analysis says there is a mate in 13 moves.

I'm correct thinking there is a mistake? Or am I missing something?

```
5Kbk/6pp/6P1/8/7R/8/8/8 w - - 0 1

```

Edit: here the solution that the engine didn't find:

```
1. Rh6 gxh6 2. g7#

```

# Answer
On the assumption that the problem is a #2, white to move (which might be entirely wrong), you are missing something.

Forget about white for the moment, but consider what black's options are if it was black to move. Mainly Bishop moves, and as those drop the guard of h7, Black will be mated in the following move (with one exception)

Now go back to white to move: is there any white move that will retain that situation (i.e. that black's move will lose), and take away that single exception, without producing any other advantage for Black? Once you know how black can escape a #2 when black moves, it should not be difficult.

In the chess problem workd, this is known as a block position, and it is a kind of judo chess problem.

Many, perhaps most, chess playing engines struggle with these types of positions.

(Edit: Doesn't the book have solutions?)
> 3 votes

# Answer
Checking a chess analysis board myself, there is a mate in thirteen with black to move. It is very likely that this is what you set up on chess.com.

The puzzle was certainly intended with white to move. Try again to find the mate in two with white moving first, yourself. And, if you do want to use the computer again, make sure you set it up correctly with which side has the move.
> 1 votes

---
Tags: checkmate, puzzles
---


# Question
Title: Is there a name for the pattern when a bishop on the fifth rank is driven back to the third rank by pawns?
I've noticed a common theme in games where a bishop placed on the fifth rank winds up retreating to the third rank as it's threatened by pawns. (as the black player this would be a bishop on the fourth rank pushed back to the sixth). A common example would be white's light-squared bishop in the Ruy Lopez: Morphy Defense, Caro Variation.

```
[Title "Ruy Lopez: Morphy Defense, Caro Variation"]
[FEN ""]
[StartPly "8"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5

```

However, this could happen at any point in the game, with any bishop of any color. I notice it often when a bishop is placed pinning a knight to a king, then attacked by an a or h pawn at a time when trading for the knight is not advantageous. Is there a name for this zig-zagging bishop retreat pattern?

# Answer
The first move (...a6) is known as "putting the question to the bishop". It asks the bishop to clarify its intentions - does it want to trade itself for the knight, or would it rather back off?

I'm not aware of a name for ...b5, however.
> 1 votes

---
Tags: terminology, bishops
---


# Question
Title: Who is the most unfortunate player in chess history?
I'm interested in candidates for a "most unfortunate chess player award".

A player qualifies, if

* he has had exceptionally bad luck (especially chess-related (e.g. coming second, losing due to circumstances, not being able to participate in competitions, lacking funds, ...), but private bad luck would also qualify)
* never won (one of) the most significant titles / tournaments of his era (that would have him widely remembered)
* was a very strong player (e.g. top 20 of his time)
* is (now) significantly less famous than the best-known player(s) of his time

This can be contemporary players, but even historic players starting from the 1500s.

I'm hoping for candidates ranging from early italian/spanish masters to today. (Who was the second-best during Philidor's time, for example; What about the time of Staunton, Morphy, Steinitz? During the reign of Lasker (Schlechter?!). What about Keres, Korchnoi, Bronstein, ...?

Please present qualified candidates.

# Answer
> 1 votes
### Ian Alexandrovich Nepomniachtchi

As a very 'promising' candidate, take **Nepo**: He did not only start early to be the "eternal runner-up" (e.g. in the prestigeous 2007 Tata Steel Tournament), he came second at least 7 times in world championship matches / tournaments, including:

* World Rapid Championship 2013
* World Blitz Championship 2014
* World Rapid Championship 2015
* World Chess Championship 2021
* World Rapid Championship 2021
* Chess960 Championship 2022
* World Chess Championship 2023

Always coming very close to the title, that slipped away from him in the last moments (often in the tie-breaks or Armageddon). Other players like Anand also had many runner-up placements, but he doesn't qualify, as he eventually became the 15th World Chess Champion.

Especially the World Chess Championship 2023 is bitter for him. He won the last 2 candidate tournaments (the hardest tournament in chess) with a superb performance (the best ever achieved) with even a round to spare in **both** tournaments. Then he loses to the runner-up of the 2022 candidates in the "rapid lottery" after having had great chances to win the title in the Classical section of the championship. And this runner-up was the most unlikely of all possible opponents. Not even qualified for the candidates, who got selected by FIDE as a wild card following the disqualification of GM Karjakin due to his support of Russian aggression against Ukraine. In a sense, GM Ding Liren might be the luckiest chess player of all time, because Carlsen decided not to defend his title, and the second place in the candidates sufficed for playing the match. He then barely managed to become second place, after Nakamura lost a game that he only needed to draw in order to play. None of this, war in Ukraine, Karjakin's reactions, FIDE's reactions, Carlsen's decision, Nakamura's performance etc. was in the hands of either player.

Nepo's peak rank was 2, with a peak rating of 2795. It is likely that Carlsen will be much more famous in the future than him, just as he is now.

---
Tags: history, famous-players, reference-request
---


# Question
Title: Algorithm for generating Jamboree chess pairings
Is there any algorithm that generates pairings for a Jamboree chess tournament, given the number of teams, the number of players in each team (no. boards) and the number of rounds? I've read somewhere that you can extrapolate the pairings for smaller numbers of teams to find those for more teams, but I'm slightly unsure how to do this?

We are trying to minimise the color difference so that in each round, the number of blacks for each team should be as close as possible to the number of whites. For odd numbers of teams, no player should have more than one up-float or more than one down-float. And, over all the rounds taken together, the number of up-floats for each team should be as close as possible to the number of down-floats.

# Answer
> 1 votes
I have found this web page with a number of Excel spreadsheets programmed for 3 round jamboree pairings for 4, 6, 8, 10, 12, 16, 20 board matches with 3 to 26 teams. Also 12 board 2 round jamboree and 12 board 5 round.

Maybe you can download the spreadsheets and work out the algorithms used if they don't cover your use case.

# Answer
> 1 votes
Please don't enter into any correspondence related to this question before Wednesday 13 December; it is a question in the Ritangle competition which ends on 12/12/23. The poster knows that seeking such help is not within the rules. Thank you.

---
Tags: tournament, jamboree, pairing
---


title: Questions about legality of last move

text:
# Question
Title: Questions about legality of last move
Question for FIDE Arbiters and similar knowledgeable folk...

> **FIDE Law Article 5.1.1** The game is won by the player who has checkmated his/her opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was in accordance with Article 3 and Articles 4.2 – 4.7.

Article 3 covers the moves of the pieces, while Article 4 covers touch-move.

Exactly the same final sentence is used with 5.2.1 Stalemate and 5.2.2 Dead Position.

Motivation: I am trying to understand the background for this final sentence, for purposes of fairy chess problems & illegal positions. I think we should be able to evaluate the game state, even if there is no possible history. For example, some problems involve set play, where the player to move is flipped - there is no requirement that a set play position be legal.

Here's an instance:

```
8/8/8/8/8/8/PPrp4/KRk5 w - - 0 1

```

(If you think this position is more complicated than it needs to be, for absolute watertightness, remember that we need to ensure that there is no possible last move that White may have made, even from an illegal position where White (to move) was already apparently checking Black! (So-called "lèse-majesté" situation.))

We would say that this is checkmate, but ah no according to FIDE Laws it isn't because there's no legal prior move. So we are stuck in a hole: there are no legal moves, but the game isn't over.

In practical terms, I will recommend that the Chess Problem Codex https://www.wfcc.ch/1999-2012/codex/ should exclude this sentence, wherever it occurs, from application to problems.

But I still want to understand the rule from an otb (over the board) perspective.

(1) What does "immediately" mean? Don't have to hit the clock? Don't have to write the move? Counter for 50-move immediately suspended? (So one can't draw & win the game at the same time.)

(2) Why does only the **last** move have to be legal?

(3) What happens if there was an earlier uncorrected legality? Does it matter if the **position** is legal or illegal prior to the final move?

Side remark: for some reason Article 4.1 ("Each move must be played with one hand only.") is explicitly excluded from the scope. FIDE clearly intend that a player may theatrically make their final move with both hands, as if straining to lift and place a huge weight! This is covered here: Mate with both hands: Result?

# Answer
Answer to 1.

For concise rules, FIDE differs between making a move and completing a move (and notating a move, which has no effects on play whatsoever, except that §8 is coming on you if you neglect it). Thus:

* Yes, "ending" moves end the game immediately, §5.
* While it's not explicitely written down in §5, it suffice to make the move.
* You don't have to complete it (by pressing the clock) nor write it down.
* The 50 move/triple repetition check will only set in *after* completing the move, thus the ending move has the right of way.
* As a corollary, even a spectator can scream "Mate!" (but this is still frowned upon, even on kids tourneys).

Answer to 2:

"Why" questions need a psychic, but FIDE implicitely assumes that at the first illegality a referee interferes (or at least a player protests). If that doesn't happen, what could one do anyway?

* Thus only an illegality that is irrevocable (ends the game on the spot) *must* be checked.
* Even in that case, if, say, the loser accepts the mate, shakes hands and signs the sheets, the result will normally stand if the player finds a "Wait? The mating move was illegal!!" in the analysis.

Answer to 3:

This is explicitly in the rulebook also (§7).

* An illegality found *during the game* must be corrected. Even if was 100 moves ahead ($7.4). (Think of the referee coming to the board and see two same-colored bishops...)
* And this "during" is the whole reason to the formulation, since mate ends the game, so otherwise you could mate with an illegal move and claim it can't be corrected since the game has ended.
* As a corollary (to deal with your comment), if you steal the queen of your opponent somewhen in the game who doesn't realize it until mated - tough luck. In-game rules are on your side in this case, but expect to not celebrate victory for long. A tournament jury might bring the Catch-Em-All (§12.1) on you and restore the "just" result by §13.4! (I don't know of an actual case, naturally.)
> 4 votes

---
Tags: fide, problems, checkmate, stalemate, dead-position
---


# Question
Title: Can the game end in multiple ways at the same time?
We know that a game can't end in checkmate and draw by 50 move rule. The checkmate will take precedence.

But just for fun let's ask: is it possible for a game to end in both draw by repetition & draw by 50 move? Can a player make two claims simultaneously? Or one after the other?

Or can two players simultaneously resign?

These are just examples: the main question is what are all the combinations of multiple game-end conditions?

# Answer
> 7 votes
> Can a player make two claims simultaneously?

No. When you make a draw claim your are asking the arbiter to perform the task of investigating / verifying your claim. One arbiter can only investigate one claim at a time.

Here is what should happen when you claim a draw:

1. Arbiter asks your opponent if they would accept a draw. This is because a failed draw claim turns into a formal draw offer and if your opponent is happy to accept a draw then there is no need to proceed further. The game is agreed drawn
2. Arbiter asks if you touched a piece before starting the draw claim procedure. This is because if you did then you are obliged to move a piece and can't claim a draw on that move
3. Arbiter actually checks the details of the claim. Is it valid? This involves checking the moves made in some way. For most tournaments this means looking at the scoresheets. If the games are being broadcast then it can be easier (for both handwriting and accuracy reasons) to use the replayer on the broadcasting site.
4. If the claim is found to be valid then the game is declared drawn.
5. If the claim is found to be not valid then in the first instance a draw offer is made to the opponent (they can still change their mind and accept even if they declined at step 1). In the case of a 3-fold repetition where the the claimant said that move X would repeat the position for the third time, that move move has to be made. Otherwise the claimant is free to choose any legal move. Meanwhile the opponent gets an additional 2 minutes on the clock as compensation for the disturbance. The game then continues.

> Or one after the other?

If the first claim fails then further claims, either on the same move or on later moves, are allowed. If you make further failed claims then each failed claim results in an additional 2 minutes for the opponent. You cannot limit this potential time loss by making two claims at once.

# Answer
> 7 votes
You could try to complete your second illegal move in a position your opponent cannot win while simultaneously agreeing to a draw at exactly at the same time that your flag falls, but closer examination would probably reveal that one thing happened before the others.

As for "dead position" draws, it's *technically* true that if the game ended in a draw due to some other reason, it also necessarily means that there is no legal series of moves for either side that could checkmate the opponent, but I don't think that's really in the spirit of the question.

The 75-move and 5-move rules do not involve claims, so I think the issue with choosing the claim like the scenario with the 50-move and 3-move rules would not apply. But the rules specifically contemplate that "If one or both of the following occur(s) then the game is drawn" in regards to the 75-move and 5-move rules. So you could argue that "simultaneous 75-move and 5-move" is actually the *same* way, since it's one rule making that situation a draw.

But, I think a simultaneous stalemate and 75-move draw would work. The 75-move rule explicitly states that checkmate takes precedence, but is silent on stalemate.

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Tags: rules, draw, claim-draw, winning
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