The longest checkmate question

[Chessqueen]

Thanks for link, we have now a new record!

And this is the longest mate with 7 pieces This position is solved by endgame tablebases to be a white win in 524 moves (with black to play).
This is not normally what you think of as checkmate in X, but it will in fact be checkmate in 524 moves with best play from both sides.

Note: What is the longest checkmate by any human GM, that is what matter, NOT what EGTB can accomplish, and what GM sacrificed the most pieces, probably this game. Also I believe that there has only been one case of a checkmate in any World Chess Championship.

[Chessqueen]

Thanks for link, we have now a new record!

And this is the longest mate with 7 pieces This position is solved by endgame tablebases to be a white win in 524 moves (with black to play).
This is not normally what you think of as checkmate in X, but it will in fact be checkmate in 524 moves with best play from both sides.

Note: What is the longest checkmate by any human GM, that is what matter, NOT what EGTB can accomplish, and what GM sacrificed the most pieces, probably this game. Also I believe that there has only been one case of a checkmate in any World Chess Championship.

I guess nobody know for sure what has been the longest checkmate between GMs since there only has been one Checkmate in World Chess Championship, and that is because most top GMs see a checkmate at least 4 to 5 moves before it is executed or they simply resign in a hopeless or lost position. I would add that Bogoljubov was either drunk or NOT a TOP GM to see that the Checkmate was unavoidable, since most GM today rated around 2400 would have seen this coming 4 moves before it was executed, he should had resigned even 2 moves before, ===>

[xr_a_y]

Which position known has the longest checkmate under the 50-move rule?

The longest checkmate "under the 50move rule" is probably exactly in 50 moves no ?

The path to checkmate can easily be longer than 50 moves, just needs to reset the 50 moves counter in time.

oops, sure, you are right of course.

[Sopel]

Guys, the question explicitly said that the solution should respect 50-move rule, I'm also curious, please stop posting irrelevant garbage.

[Jouni]

The link says 584 moves to 7 piece. And the endposition is mate in 8. So record is 592 moves. Sorry off-topic garbage.

[Spliffjiffer]

Which position known has the longest checkmate under the 50-move rule?

there was a time when i thought that this is the ultimately longest checkmate around made by a human but i was definately wrong though:
[d]8/Bk3p1p/1P3p2/KP2n2p/1P1p4/1Pp2p2/B1P5/7B w - - 0 1
Nenad Petrovic, Zagreb 1969, Mate In 271

probably most of you did see this composition already so its not much of any help unfortunately...
after a quick google search i found this commentary about the (human made composition)-side-theme here:
https://chess.stackexchange.com/questio ... s-composed

[Spliffjiffer]

Which position known has the longest checkmate under the 50-move rule?

there was a time when i thought that this is the ultimately longest checkmate around made by a human but i was definately wrong though:
[d]8/Bk3p1p/1P3p2/KP2n2p/1P1p4/1Pp2p2/B1P5/7B w - - 0 1
Nenad Petrovic, Zagreb 1969, Mate In 271

probably most of you did see this composition already so its not much of any help unfortunately...
after a quick google search i found this commentary about the (human made composition)-side-theme here:
https://chess.stackexchange.com/questio ... s-composed

the same commentator gives this suggestion for the longest ever-made checkmate by a human:
[d]bBrb1B2/P1n1r1bp/pKp1P2p/2pk1P1p/5P1p/1P2pP1p/1pP1P2p/1R5n w - - 0 1

[pgn]
[White "Spliff"]
[Black "Spliff"]
[FEN "bBrb1B2/P1n1r1bp/pKp1P2p/2pk1P1p/5P1p/1P2pP1p/1pP1P2p/1R5n w - - 0 1 "]
[Termination "normal"]
[PlyCount "829"]
[WhiteType "human"]
[BlackType "human"]

1. Rd1+ Bd4 2. c4+ Kd6 3. Rxh1 Bc3 4. Rd1+ Bd4 5. Ka5 Bb7 6. Ka4 Ba8 7. Ka3
Bb7 8. Ka2 Ba8 9. Kb1 Bb7 10. Kc2 Ba8 11. Kd3 Bb7 12. Rh1 Ba8 13. Rf1 Bb7
14. Rd1 Ba8 15. Kc2 Bb7 16. Kb1 Ba8 17. Ka2 Bb7 18. Ka3 Ba8 19. Ka4 Bb7 20.
Ka5 Ba8 21. Kb6 h1=Q 22. Rxh1 Bc3 23. Rd1+ Bd4 24. Ka5 Bb7 25. Ka4 Ba8 26.
Ka3 Bb7 27. Ka2 Ba8 28. Kb1 Bb7 29. Kc2 Ba8 30. Kd3 Bb7 31. Rh1 Ba8 32. Rf1
Bb7 33. Rd1 Ba8 34. Kc2 Bb7 35. Kb1 Ba8 36. Ka2 Bb7 37. Ka3 Ba8 38. Ka4 Bb7
39. Ka5 Ba8 40. Kb6 h2 41. Ka5 Bb7 42. Ka4 Ba8 43. Ka3 Bb7 44. Ka2 Ba8 45.
Kb1 Bb7 46. Kc2 Ba8 47. Kd3 Bb7 48. Rh1 Ba8 49. Rf1 Bb7 50. Rd1 Ba8 51. Kc2
Bb7 52. Kb1 Ba8 53. Ka2 Bb7 54. Ka3 Ba8 55. Ka4 Bb7 56. Ka5 Ba8 57. Kb6 h3
58. Ka5 Bb7 59. Ka4 Ba8 60. Ka3 Bb7 61. Ka2 Ba8 62. Kb1 Bb7 63. Kc2 Ba8 64.
Kd3 Bb7 65. Rh1 Ba8 66. Rf1 Bb7 67. Rd1 Ba8 68. Kc2 Bb7 69. Kb1 Ba8 70. Ka2
Bb7 71. Ka3 Ba8 72. Ka4 Bb7 73. Ka5 Ba8 74. Kb6 h4 75. Ka5 Bb7 76. Ka4 Ba8
77. Ka3 Bb7 78. Ka2 Ba8 79. Kb1 Bb7 80. Kc2 Ba8 81. Kd3 Bb7 82. Rh1 Ba8 83.
Rf1 Bb7 84. Rd1 Ba8 85. Kc2 Bb7 86. Kb1 Ba8 87. Ka2 Bb7 88. Ka3 Ba8 89. Ka4
Bb7 90. Ka5 Ba8 91. Kb6 h5 92. Ka5 Bb7 93. Ka4 Ba8 94. Ka3 Bb7 95. Ka2 Ba8
96. Kb1 Bb7 97. Kc2 Ba8 98. Kd3 Bb7 99. Rh1 Ba8 100. Rf1 Bb7 101. Rd1 Ba8
102. Kc2 Bb7 103. Kb1 Ba8 104. Ka2 Bb7 105. Ka3 Ba8 106. Ka4 Bb7 107. Ka5
Ba8 108. Kb6 h6 109. Ka5 Bb7 110. Ka4 Ba8 111. Ka3 Bb7 112. Ka2 Ba8 113.
Kb1 Bb7 114. Kc2 Ba8 115. Kd3 Bb7 116. Rh1 Ba8 117. Rf1 Bb7 118. Rd1 Ba8
119. Kc2 Bb7 120. Kb1 Ba8 121. Ka2 Bb7 122. Ka3 Ba8 123. Ka4 Bb7 124. Ka5
Ba8 125. Kb6 h1=Q 126. Rxh1 Bc3 127. Rd1+ Bd4 128. Ka5 Bb7 129. Ka4 Ba8
130. Ka3 Bb7 131. Ka2 Ba8 132. Kb1 Bb7 133. Kc2 Ba8 134. Kd3 Bb7 135. Rh1
Ba8 136. Rf1 Bb7 137. Rd1 Ba8 138. Kc2 Bb7 139. Kb1 Ba8 140. Ka2 Bb7 141.
Ka3 Ba8 142. Ka4 Bb7 143. Ka5 Ba8 144. Kb6 h2 145. Ka5 Bb7 146. Ka4 Ba8
147. Ka3 Bb7 148. Ka2 Ba8 149. Kb1 Bb7 150. Kc2 Ba8 151. Kd3 Bb7 152. Rh1
Ba8 153. Rf1 Bb7 154. Rd1 Ba8 155. Kc2 Bb7 156. Kb1 Ba8 157. Ka2 Bb7 158.
Ka3 Ba8 159. Ka4 Bb7 160. Ka5 Ba8 161. Kb6 h3 162. Ka5 Bb7 163. Ka4 Ba8
164. Ka3 Bb7 165. Ka2 Ba8 166. Kb1 Bb7 167. Kc2 Ba8 168. Kd3 Bb7 169. Rh1
Ba8 170. Rf1 Bb7 171. Rd1 Ba8 172. Kc2 Bb7 173. Kb1 Ba8 174. Ka2 Bb7 175.
Ka3 Ba8 176. Ka4 Bb7 177. Ka5 Ba8 178. Kb6 h4 179. Ka5 Bb7 180. Ka4 Ba8
181. Ka3 Bb7 182. Ka2 Ba8 183. Kb1 Bb7 184. Kc2 Ba8 185. Kd3 Bb7 186. Rh1
Ba8 187. Rf1 Bb7 188. Rd1 Ba8 189. Kc2 Bb7 190. Kb1 Ba8 191. Ka2 Bb7 192.
Ka3 Ba8 193. Ka4 Bb7 194. Ka5 Ba8 195. Kb6 h5 196. Ka5 Bb7 197. Ka4 Ba8
198. Ka3 Bb7 199. Ka2 Ba8 200. Kb1 Bb7 201. Kc2 Ba8 202. Kd3 Bb7 203. Rh1
Ba8 204. Rf1 Bb7 205. Rd1 Ba8 206. Kc2 Bb7 207. Kb1 Ba8 208. Ka2 Bb7 209.
Ka3 Ba8 210. Ka4 Bb7 211. Ka5 Ba8 212. Kb6 h1=Q 213. Rxh1 Bc3 214. Rd1+ Bd4
215. Ka5 Bb7 216. Ka4 Ba8 217. Ka3 Bb7 218. Ka2 Ba8 219. Kb1 Bb7 220. Kc2
Ba8 221. Kd3 Bb7 222. Rh1 Ba8 223. Rf1 Bb7 224. Rd1 Ba8 225. Kc2 Bb7 226.
Kb1 Ba8 227. Ka2 Bb7 228. Ka3 Ba8 229. Ka4 Bb7 230. Ka5 Ba8 231. Kb6 h2
232. Ka5 Bb7 233. Ka4 Ba8 234. Ka3 Bb7 235. Ka2 Ba8 236. Kb1 Bb7 237. Kc2
Ba8 238. Kd3 Bb7 239. Rh1 Ba8 240. Rf1 Bb7 241. Rd1 Ba8 242. Kc2 Bb7 243.
Kb1 Ba8 244. Ka2 Bb7 245. Ka3 Ba8 246. Ka4 Bb7 247. Ka5 Ba8 248. Kb6 h3
249. Ka5 Bb7 250. Ka4 Ba8 251. Ka3 Bb7 252. Ka2 Ba8 253. Kb1 Bb7 254. Kc2
Ba8 255. Kd3 Bb7 256. Rh1 Ba8 257. Rf1 Bb7 258. Rd1 Ba8 259. Kc2 Bb7 260.
Kb1 Ba8 261. Ka2 Bb7 262. Ka3 Ba8 263. Ka4 Bb7 264. Ka5 Ba8 265. Kb6 h4
266. Ka5 Bb7 267. Ka4 Ba8 268. Ka3 Bb7 269. Ka2 Ba8 270. Kb1 Bb7 271. Kc2
Ba8 272. Kd3 Bb7 273. Rh1 Ba8 274. Rf1 Bb7 275. Rd1 Ba8 276. Kc2 Bb7 277.
Kb1 Ba8 278. Ka2 Bb7 279. Ka3 Ba8 280. Ka4 Bb7 281. Ka5 Ba8 282. Kb6 h1=Q
283. Rxh1 Bc3 284. Rd1+ Bd4 285. Ka5 Bb7 286. Ka4 Ba8 287. Ka3 Bb7 288. Ka2
Ba8 289. Kb1 Bb7 290. Kc2 Ba8 291. Kd3 Bb7 292. Rh1 Ba8 293. Rf1 Bb7 294.
Rd1 Ba8 295. Kc2 Bb7 296. Kb1 Ba8 297. Ka2 Bb7 298. Ka3 Ba8 299. Ka4 Bb7
300. Ka5 Ba8 301. Kb6 h2 302. Ka5 Bb7 303. Ka4 Ba8 304. Ka3 Bb7 305. Ka2
Ba8 306. Kb1 Bb7 307. Kc2 Ba8 308. Kd3 Bb7 309. Rh1 Ba8 310. Rf1 Bb7 311.
Rd1 Ba8 312. Kc2 Bb7 313. Kb1 Ba8 314. Ka2 Bb7 315. Ka3 Ba8 316. Ka4 Bb7
317. Ka5 Ba8 318. Kb6 h3 319. Ka5 Bb7 320. Ka4 Ba8 321. Ka3 Bb7 322. Ka2
Ba8 323. Kb1 Bb7 324. Kc2 Ba8 325. Kd3 Bb7 326. Rh1 Ba8 327. Rf1 Bb7 328.
Rd1 Ba8 329. Kc2 Bb7 330. Kb1 Ba8 331. Ka2 Bb7 332. Ka3 Ba8 333. Ka4 Bb7
334. Ka5 Ba8 335. Kb6 h1=Q 336. Rxh1 Bc3 337. Rd1+ Bd4 338. Ka5 Bb7 339.
Ka4 Ba8 340. Ka3 Bb7 341. Ka2 Ba8 342. Kb1 Bb7 343. Kc2 Ba8 344. Kd3 Bb7
345. Rh1 Ba8 346. Rf1 Bb7 347. Rd1 Ba8 348. Kc2 Bb7 349. Kb1 Ba8 350. Ka2
Bb7 351. Ka3 Ba8 352. Ka4 Bb7 353. Ka5 Ba8 354. Kb6 h2 355. Ka5 Bb7 356.
Ka4 Ba8 357. Ka3 Bb7 358. Ka2 Ba8 359. Kb1 Bb7 360. Kc2 Ba8 361. Kd3 Bb7
362. Rh1 Ba8 363. Rf1 Bb7 364. Rd1 Ba8 365. Kc2 Bb7 366. Kb1 Ba8 367. Ka2
Bb7 368. Ka3 Ba8 369. Ka4 Bb7 370. Ka5 Ba8 371. Kb6 h1=Q 372. Rxh1 Bc3 373.
Rd1+ Bd4 374. Ka5 Bb7 375. Ka4 Ba8 376. Ka3 Bb7 377. Ka2 Ba8 378. Kb1 Bb7
379. Kc2 Ba8 380. Kd3 Bb7 381. Rh1 Ba8 382. Rf1 Bb7 383. Rd1 Ba8 384. Kc2
Bb7 385. Kb1 Ba8 386. Ka2 Bb7 387. Ka3 Ba8 388. Ka4 Bb7 389. Ka5 Ba8 390.
Kb6 a5 391. Kxa5 Bb7 392. Ka4 Ba8 393. Ka3 Bb7 394. Ka2 Ba8 395. Kb1 Bb7
396. Kc2 Ba8 397. Kd3 Bb7 398. Rh1 Ba8 399. Rf1 Bb7 400. Rd1 Ba8 401. Kc2
Bb7 402. Kb1 Ba8 403. Ka2 Bb7 404. Ka3 Ba8 405. Ka4 Bb7 406. Ka5 Ba8 407.
Kb6 Bb7 408. Kxb7 b1=Q 409. Rxb1 Be5 410. Rd1+ Bd4 411. Rxd4+ cxd4 412. Kb6
d3 413. a8=Q Rxb8+ 414. Qxb8 d2 415. Qxd8#

[/pgn]

sry, somehow the PGN doesnt accept the fen because the pos is illegal

[Chessqueen]

Which position known has the longest checkmate under the 50-move rule?

there was a time when i thought that this is the ultimately longest checkmate around made by a human but i was definately wrong though:
[d]8/Bk3p1p/1P3p2/KP2n2p/1P1p4/1Pp2p2/B1P5/7B w - - 0 1
Nenad Petrovic, Zagreb 1969, Mate In 271

probably most of you did see this composition already so its not much of any help unfortunately...
after a quick google search i found this commentary about the (human made composition)-side-theme here:
https://chess.stackexchange.com/questio ... s-composed

the same commentator gives this suggestion for the longest ever-made checkmate by a human:
[d]bBrb1B2/P1n1r1bp/pKp1P2p/2pk1P1p/5P1p/1P2pP1p/1pP1P2p/1R5n w - - 0 1

This is NOT possible game played by two humans, since there are 11 black pawns

[Spliffjiffer]

Which position known has the longest checkmate under the 50-move rule?

there was a time when i thought that this is the ultimately longest checkmate around made by a human but i was definately wrong though:
[d]8/Bk3p1p/1P3p2/KP2n2p/1P1p4/1Pp2p2/B1P5/7B w - - 0 1
Nenad Petrovic, Zagreb 1969, Mate In 271

probably most of you did see this composition already so its not much of any help unfortunately...
after a quick google search i found this commentary about the (human made composition)-side-theme here:
https://chess.stackexchange.com/questio ... s-composed

the same commentator gives this suggestion for the longest ever-made checkmate by a human:
[d]bBrb1B2/P1n1r1bp/pKp1P2p/2pk1P1p/5P1p/1P2pP1p/1pP1P2p/1R5n w - - 0 1

This is NOT possible game played by two humans, since there are 11 black pawns

is this @copyresist or whhat?

[Uri Blass]

Which position known has the longest checkmate under the 50-move rule?

there was a time when i thought that this is the ultimately longest checkmate around made by a human but i was definately wrong though:
[d]8/Bk3p1p/1P3p2/KP2n2p/1P1p4/1Pp2p2/B1P5/7B w - - 0 1
Nenad Petrovic, Zagreb 1969, Mate In 271

probably most of you did see this composition already so its not much of any help unfortunately...
after a quick google search i found this commentary about the (human made composition)-side-theme here:
https://chess.stackexchange.com/questio ... s-composed

I wonder if the longest composition with unique solution really has a unique solution.

They claim the following is a long mate with a unique solution but I suspect the solution is wrong and there is a shorter mate in less than 226 moves.

[fen]1N2Q3/p6n/p5n1/p1p2rpb/p4k1r/K1P4p/2PP4/6B1 w - - 6 1 [/fen]

They give 56.Kc1 in the solution but 56.c4 may be stronger.
[fen]8/p2N3n/p3Q1n1/p1p2rpb/6kr/2P4p/1KPP3B/8 w - - 23 56 [/fen]

after 56.c4 black has only 2 options not to lose by a fast checkmate:
56...a4 and 56...Kf3

After 56.c4 a4 57.c3 or 56.c4 Kf3 57.Qe3+ I could get by stockfish to see more than +6 by some backward analysis of not many moves so it seems that the solution is not unique and probably shorter than 226 moves even if stockfish did not see a mate score.