2

It has been asked the longest mate that includes draw rules is, and it is known what the longest tablebase mate is. However, what is the longest tablebase mate, i.e. 7 pieces or less, that accounts for the 50-move rule?

So far, I have looked at Kirill Kryukov's page for longest mates for up to 6 pieces. I looked for positions where White has at least two pawns and tested to see if they are a "cursed" win or not in Sygyzy, along with checking Shredder for the DTM. Lichess is great for playing out the moves so they can be copy and pasted.

The 5-piece endgame KPPKQ has the longest sequence I know of so far, with a DTM of 248 ply. Here is the full sequence to show how White must be able to make a pawn move every so often to reset the 50-move counter in order to win. I added on an extra move for each side, so the current record is 250 ply.

[FEN "8/4q3/5P1Q/8/8/8/k1K1P3/7q w - - 0 1"]

1. fxe7 Qxh6 2. e8=Q Qh7+ 3. Kc3 Qc7+ 4. Kd4 Qb6+ 5. Kd5 Qb3+ 6. Ke4 Qd1 7. e3 Qe2 8. Kf4 Qf2+ 9. Kg5 Qg1+ 10. Kf6 Qf2+ 11. Kg7 Qb2+ 12. Kh7 Qb7+ 13. Kh6 Qb6+ 14. Kg5 Kb3 15. Kf5 Qc5+ 16. Kf6 Kc2 17. Qe4+ Kc1 18. Kf7 Qh5+ 19. Ke7 Qc5+ 20. Kd7 Qa7+ 21. Ke8 Qb8+ 22. Kf7 Qc7+ 23. Qe7 Qc4+ 24. Qe6 Qc7+ 25. Kf6 Qc3+ 26. Qe5 Qc6+ 27. Ke7 Qb7+ 28. Kd8 Qa8+ 29. Kd7 Qa4+ 30. Ke7 Qb4+ 31. Ke6 Qc4+ 32. Qd5 Qc8+ 33. Ke7 Qc7+ 34. Kf6 Qc3+ 35. Qd4 Qc8 36. Kf7 Qb7+ 37. Kg6 Qc6+ 38. Kf5 Qb5+ 39. Kf4 Qf1+ 40. Ke4 Qg2+ 41. Ke5 Qg5+ 42. Ke6 Qg8+ 43. Kd7 Qf7+ 44. Kc6 Qe8+ 45. Kc7 Qf7+ 46. Kb6 Qb3+ 47. Kc6 Qe6+ 48. Kc5 Qc8+ 49. Kb4 Qb7+ 50. Kc3 Qc6+ 51. Qc4 Qf3 52. Kd4+ Kd2 53. Qd3+ Ke1 54. e4 Qf6+ 55. Kc5 Qe7+ 56. Kb6 Qe6+ 57. Ka5 Qa2+ 58. Kb5 Qb2+ 59. Kc6 Qe5 60. Qd5 Qh8 61. Qf5 Qe8+ 62. Kc5 Qe7+ 63. Kc4 Qc7+ 64. Qc5 Qf4 65. Qd4 Qf7+ 66. Kc3 Qf3+ 67. Kb2 Qg2+ 68. Ka1 Qf3 69. e5 Ke2 70. Ka2 Qc6 71. Ka3 Qf3+ 72. Kb4 Qb7+ 73. Kc4 Qc6+ 74. Qc5 Qa4+ 75. Kd5 Qd7+ 76. Qd6 Qb5+ 77. Ke6 Qb3+ 78. Qd5 Qb6+ 79. Kf5 Qf2+ 80. Kg5 Qg1+ 81. Kh6 Qe3+ 82. Kh5 Qh3+ 83. Kg6 Qg4+ 84. Kf6 Qh4+ 85. Kf7 Qh5+ 86. Ke7 Qg5+ 87. Kd7 Qf5+ 88. Kd6 Qf8+ 89. Kc7 Qf4 90. Kb6 Ke3 91. e6 Qb8+ 92. Kc5 Qc7+ 93. Qc6 Qe5+ 94. Kb6 Qb8+ 95. Ka6 Qe5 96. Qd7 Qa1+ 97. Kb6 Qb2+ 98. Qb5 Qf6 99. Qd5 Ke2 100. Kc6 Qg6 101. Kd7 Qg4 102. Qe5+ Kf2 103. Ke7 Qg8 104. Qf5+ Ke1 105. Kd7 Qa8 106. e7 Qa4+ 107. Kd6 Qa6+ 108. Ke5 Qb5+ 109. Kf6 Qe8 110. Qe6+ Kd1 111. Kg7 Kc1 112. Qf7 Qa4 113. e8=Q Qd4+ 114. Qf6 Qg4+ 115. Kh7 Qh3+ 116. Qh6+ Qxh6+ 117. Kxh6 Kd1 118. Qe3 Kc2 119. Kg5 Kb1 120. Qd2 Ka1 121. Kf4 Kb1 122. Ke3 Ka1 123. Kd3 Kb1 124. Kc3 Ka1 125. Qb2#

Who knows of/can find a longer such sequence? Additionally, if you are able to, give the moves for the position along with your answer please.

3

I randomly came across the endgame KQPPKQ and I decided to plug it into Sygyzy for the heck of it. To my surprise, it was not cursed win! With a further ply added, it is a new record of 364 ply.

[FEN "7q/4k3/8/Q7/8/7P/P7/Q1K5 b - - 0 1"]

1... Qxa1+ 2. Kc2 Qd4 3. Qe1+ Kf7 4. Qf1+ Kg7 5. Qg2+ Kh8 6. Qa8+ Kh7 7. Qb7+ Kh6 8. Qc6+ Kh5 9. Qe8+ Kg5 10. Qg8+ Kh6 11. Qe6+ Kh7 12. Kb3 Qd3+ 13. Kb4 Qd2+ 14. Kb5 Qd3+ 15. Qc4 Qf5+ 16. Kb6 Qf2+ 17. Kb7 Qf3+ 18. Kc7 Qa3 19. Kb6 Kh8 20. Qd4+ Kh7 21. Qd7+ Kg6 22. Qe6+ Kh5 23. Qd5+ Kg6 24. Kb5 Qb2+ 25. Kc6 Qc3+ 26. Kd7 Qg7+ 27. Kd6 Qf8+ 28. Kc7 Qf2 29. Kc6 Qe2 30. Kd7 Qf2 31. Qe6+ Kg7 32. Kc6 Qf3+ 33. Kb6 Qa3 34. Qb3 Qd6+ 35. Ka7 Qc5+ 36. Kb7 Qe7+ 37. Ka8 Qd8+ 38. Qb8 Qh4 39. Qb7+ Kf8 40. Qc8+ Ke7 41. Kb8 Qa4 42. Qc5+ Kd8 43. Qg5+ Ke8 44. Qe3+ Kf8 45. Qf3+ Ke7 46. a3 Qc4 47. Ka7 Qd4+ 48. Kb7 Qd7+ 49. Kb6 Qd4+ 50. Kb5 Qb2+ 51. Kc5 Qc2+ 52. Kd5 Qd2+ 53. Ke4 Qc2+ 54. Kf4 Qc7+ 55. Ke3 Qa7+ 56. Ke2 Qa6+ 57. Kf2 Qd6 58. Kf1 Qd4 59. Ke2 Qa4 60. Qc3 Ke8 61. Kf3 Qh4 62. Qc8+ Ke7 63. Qg4 Qf6+ 64. Qf4 Qa1 65. Qe3+ Kf8 66. Kg2 Qb1 67. Qf4+ Kg8 68. Qc4+ Kh8 69. Qd4+ Kg8 70. a4 Qg6+ 71. Kf2 Qf5+ 72. Kg3 Qg6+ 73. Kf4 Qf7+ 74. Kg5 Qe7+ 75. Qf6 Qd7 76. Qg6+ Kh8 77. Qh5+ Kg7 78. Qg4 Qd5+ 79. Qf5 Qd8+ 80. Kf4 Qd2+ 81. Kg3 Qe3+ 82. Qf3 Qg1+ 83. Kf4 Qc1+ 84. Kg4 Qc4+ 85. Qf4 Qe6+ 86. Kf3 Qb3+ 87. Kf2 Qb6+ 88. Kg3 Qg6+ 89. Kh4 Qh7+ 90. Kg4 Qg6+ 91. Qg5 Kh8 92. Kf4 Qf7+ 93. Qf5 Qc4+ 94. Qe4 Qc1+ 95. Kf5 Qc8+ 96. Qe6 Qc2+ 97. Kf6 Qf2+ 98. Ke7 Qc5+ 99. Qd6 Qa7+ 100. Qd7 Qc5+ 101. Ke6 Qc4+ 102. Ke5 Qc5+ 103. Ke4 Qc2+ 104. Kd5 Qd1+ 105. Ke6 Qe1+ 106. Kd6 Qb4+ 107. Kc7 Qf4+ 108. Kb6 Qb8+ 109. Kc5 Qe5+ 110. Qd5 Qe7+ 111. Kb6 Qb4+ 112. Qb5 Qd4+ 113. Kb7 Qe4+ 114. Kc8 Qe6+ 115. Kb8 Qg8+ 116. Ka7 Qg7+ 117. Ka8 Qg2+ 118. Qb7 Qxh3 119. a5 Qc3 120. a6 Qc4 121. Qb2+ Kh7 122. Qb6 Qc8+ 123. Ka7 Qc4 124. Kb7 Qe4+ 125. Qc6 Qb4+ 126. Ka7 Qf4 127. Qc8 Qg3 128. Ka8 Qd6 129. Qc2+ Kh6 130. Kb7 Qb4+ 131. Kc6 Qa3 132. Kb5 Kg7 133. Qc7+ Kh8 134. Qc8+ Kh7 135. Qd7+ Kg8 136. a7 Qb3+ 137. Ka6 Qa3+ 138. Kb7 Qb4+ 139. Kc7 Qc4+ 140. Kd8 Qh4+ 141. Qe7 Qd4+ 142. Kc8 Qc4+ 143. Kb8 Qb5+ 144. Qb7 Qe5+ 145. Ka8 Qc5 146. Qb3+ Kf8 147. Kb7 Qe7+ 148. Ka6 Qd6+ 149. Qb6 Qd3+ 150. Kb7 Qd7+ 151. Ka8 Qd5+ 152. Kb8 Qe5+ 153. Kb7 Qe4+ 154. Qc6 Qe7+ 155. Kb8 Qe5+ 156. Ka8 Kg8 157. Qc4+ Kh7 158. Qd3+ Kh8 159. Qd8+ Kh7 160. Kb7 Qb5+ 161. Qb6 Qd5+ 162. Qc6 Qb3+ 163. Kc7 Qg3+ 164. Qd6 Qc3+ 165. Kd7 Qf3 166. Kc8 Qe4 167. Kb8 Qb1+ 168. Kc7 Qc1+ 169. Kd7 Qh1 170. Qc6 Qh3+ 171. Kd8 Qh4+ 172. Kc8 Qb4 173. Qb7+ Qxb7+ 174. Kxb7 Kg7 175. a8=Q Kg6 176. Kc7 Kf5 177. Qa4 Ke5 178. Qg4 Kd5 179. Qf4 Kc5 180. Qe4 Kb5 181. Qd4 Ka5 182. Kc6 Ka6 183. Qb6#

Additionally, the longest sequence I have found so far for a position with no pawns in it is 182 ply, with one ply added on to the endgame KBBKNN, pulled from this list of record PGNs.

[FEN "2n5/8/3B4/8/3K3n/1B6/6Q1/2k5 b - - 0 1"]

1... Nxg2 2. Ba3+ Kd2 3. Bb4+ Ke2 4. Bc4+ Kf3 5. Bd5+ Kg3 6. Ke4 Nb6 7. Be6 Na4 8. Bb3 Nb6 9. Bc5 Nd7 10. Bd6+ Kh4 11. Be7+ Kh5 12. Be6 Nb6 13. Bc5 Na8 14. Bd7 Kh6 15. Bh3 Nh4 16. Be7 Ng6 17. Bd8 Kg7 18. Be6 Kf8 19. Kd4 Nf4 20. Bf5 Kf7 21. Ke5 Ng6+ 22. Kd6 Nf4 23. Bc8 Kg6 24. Ke5 Nd3+ 25. Kd4 Nc1 26. Bb7 Kf5 27. Ke3 Nb3 28. Bxa8 Nc5 29. Ba5 Nd7 30. Bb7 Ke6 31. Kd4 Nf6 32. Bc8+ Ke7 33. Bf5 Kf7 34. Ke5 Ne8 35. Be6+ Kg6 36. Bd8 Ng7 37. Bb3 Nh5 38. Kd6 Ng7 39. Kd7 Kf5 40. Ke7 Kf4 41. Bc7+ Ke3 42. Bb6+ Kd3 43. Bf7 Nf5+ 44. Ke6 Ne3 45. Bg6+ Ke2 46. Be4 Nc4 47. Bd4 Nd2 48. Bg6 Kf3 49. Kf5 Ke2 50. Kf4 Nb3 51. Bb6 Nd2 52. Bd8 Nb3 53. Ke5  Nd2 54. Be8 Nf3+ 55. Kf4 Nd4 56. Ke4 Nb3 57. Bh5+ Kd2 58. Bf6 Nc1 59. Bg6 Ne2 60. Bg5+ Kc3 61. Ke3 Nc1 62. Bh4 Kb4 63. Be1+ Ka4 64. Kd4 Kb3 65. Bd2 Na2 66. Bf5 Kb2 67. Kc4 Ka3 68. Be3 Kb2 69. Bd4+ Ka3 70. Bg7 Nc1 71. Bg4 Na2 72. Bd1 Nc1 73. Kc3 Na2+ 74. Kc2 Ka4 75. Kb2+ Kb4 76. Kxa2 Kc4 77. Bc2 Kc5 78. Bb3 Kc6 79. Ka3 Kc5 80. Ka4 Kc6 81. Kb4 Kc7 82. Kc5 Kd7 83. Bf8 Kc7 84. Ba4 Kb7 85. Kb5 Ka7 86. Kc6 Ka6 87. Kc7 Ka5 88. Bd7 Ka6 89. Bb4 Ka7 90. Bc8 Ka8 91. Bb7+ Ka7 92. Bc5#
| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.