Level 290

We're used to doing puzzles which might be mate-in-one (Level I), mate-in-two (Level II) and so on. Someone asked on Friday, what's the highest level you can get? Well, I have heard of a 1220-move monster by Babson, but that has some peculiar conditions.

The most moves in a forced-mate problem with no conditions is this one, from Otto Blathy, who published a whole book of such monsters.

Mate in 290 -- best of luck!

SOLUTION:

[Event "?"]
[Site "?"]
[Date "2018.04.14"]
[Round "?"]
[White "Blathy"]
[Black "Mate in 290"]
[Result "1-0"]
[Annotator "Dell"]
[SetUp "1"]
[FEN "bBrb1B2/P1n1r1bp/1Kp1P2p/2pk1P1p/5P2/1P2pP2/1pP1P3/1R4n1 w - - 0 1"]
[PlyCount "583"]
[EventDate "2018.??.??"]

1. Rd1+ Bd4 2. c4+ Kd6 3. Rxg1 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. Re1 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 h4 22. Ka5 Bb7 23. Ka4 Ba8
24. Ka3 Bb7 25. Ka2 Ba8 26. Kb1 Bb7 27. Kc2 Ba8 28. Kd3 Bb7 29. Re1 Ba8
30. Rf1 Bb7 31. Rd1 Ba8 32. Kc2 Bb7 33. Kb1 Ba8 34. Ka2 Bb7 35. Ka3 Ba8
36. Ka4 Bb7 37. Ka5 Ba8 38. Kb6 h3 39. Ka5 Bb7 40. Ka4 Ba8 41. Ka3 Bb7
42. Ka2 Ba8 43. Kb1 Bb7 44. Kc2 Ba8 45. Kd3 Bb7 46. Re1 Ba8 47. Rf1 Bb7
48. Rd1 Ba8 49. Kc2 Bb7 50. Kb1 Ba8 51. Ka2 Bb7 52. Ka3 Ba8 53. Ka4 Bb7
54. Ka5 Ba8 55. Kb6 h2 56. Ka5 Bb7 57. Ka4 Ba8 58. Ka3 Bb7 59. Ka2 Ba8
60. Kb1 Bb7 61. Kc2 Ba8 62. Kd3 Bb7 63. Re1 Ba8 64. Rf1 Bb7 65. Rd1 Ba8
66. Kc2 Bb7 67. Kb1 Ba8 68. Ka2 Bb7 69. Ka3 Ba8 70. Ka4 Bb7 71. Ka5 Ba8
72. Kb6 h5 73. Ka5 Bb7 74. Ka4 Ba8 75. Ka3 Bb7 76. Ka2 Ba8 77. Kb1 Bb7
78. Kc2 Ba8 79. Kd3 Bb7 80. Re1 Ba8 81. Rf1 Bb7 82. Rd1 Ba8 83. Kc2 Bb7
84. Kb1 Ba8 85. Ka2 Bb7 86. Ka3 Ba8 87. Ka4 Bb7 88. Ka5 Ba8 89. Kb6 h4
90. Ka5 Bb7 91. Ka4 Ba8 92. Ka3 Bb7 93. Ka2 Ba8 94. Kb1 Bb7 95. Kc2 Ba8
96. Kd3 Bb7 97. Re1 Ba8 98. Rf1 Bb7 99. Rd1 Ba8 100. Kc2 Bb7 101. Kb1
Ba8 102. Ka2 Bb7 103. Ka3 Ba8 104. Ka4 Bb7 105. Ka5 Ba8 106. Kb6 h3 107.
Ka5 Bb7 108. Ka4 Ba8 109. Ka3 Bb7 110. Ka2 Ba8 111. Kb1 Bb7 112. Kc2 Ba8
113. Kd3 Bb7 114. Re1 Ba8 115. Rf1 Bb7 116. Rd1 Ba8 117. Kc2 Bb7 118.
Kb1 Ba8 119. Ka2 Bb7 120. Ka3 Ba8 121. Ka4 Bb7 122. Ka5 Ba8 123. Kb6 h6
124. Ka5 Bb7 125. Ka4 Ba8 126. Ka3 Bb7 127. Ka2 Ba8 128. Kb1 Bb7 129.
Kc2 Ba8 130. Kd3 Bb7 131. Re1 Ba8 132. Rf1 Bb7 133. Rd1 Ba8 134. Kc2 Bb7
135. Kb1 Ba8 136. Ka2 Bb7 137. Ka3 Ba8 138. Ka4 Bb7 139. Ka5 Ba8 140.
Kb6 h5 141. Ka5 Bb7 142. Ka4 Ba8 143. Ka3 Bb7 144. Ka2 Ba8 145. Kb1 Bb7
146. Kc2 Ba8 147. Kd3 Bb7 148. Re1 Ba8 149. Rf1 Bb7 150. Rd1 Ba8 151.
Kc2 Bb7 152. Kb1 Ba8 153. Ka2 Bb7 154. Ka3 Ba8 155. Ka4 Bb7 156. Ka5 Ba8
157. Kb6 h4 158. Ka5 Bb7 159. Ka4 Ba8 160. Ka3 Bb7 161. Ka2 Ba8 162. Kb1
Bb7 163. Kc2 Ba8 164. Kd3 Bb7 165. Re1 Ba8 166. Rf1 Bb7 167. Rd1 Ba8
168. Kc2 Bb7 169. Kb1 Ba8 170. Ka2 Bb7 171. Ka3 Ba8 172. Ka4 Bb7 173.
Ka5 Ba8 174. Kb6 h1=Q 175. Rxh1 Bg7 176. Rd1+ Bd4 177. Ka5 Bb7 178. Ka4
Ba8 179. Ka3 Bb7 180. Ka2 Ba8 181. Kb1 Bb7 182. Kc2 Ba8 183. Kd3 Bb7
184. Rf1 Ba8 185. Re1 Bb7 186. Rd1 Ba8 187. Kc2 Bb7 188. Kb1 Ba8 189.
Ka2 Bb7 190. Ka3 Ba8 191. Ka4 Bb7 192. Ka5 Ba8 193. Kb6 h2 194. Ka5 Bb7
195. Ka4 Ba8 196. Ka3 Bb7 197. Ka2 Ba8 198. Kb1 Bb7 199. Kc2 Ba8 200.
Kd3 Bb7 201. Rf1 Ba8 202. Re1 Bb7 203. Rd1 Ba8 204. Kc2 Bb7 205. Kb1 Ba8
206. Ka2 Bb7 207. Ka3 Ba8 208. Ka4 Bb7 209. Ka5 Ba8 210. Kb6 h3 211. Ka5
Bb7 212. Ka4 Ba8 213. Ka3 Bb7 214. Ka2 Ba8 215. Kb1 Bb7 216. Kc2 Ba8
217. Kd3 Bb7 218. Rf1 Ba8 219. Re1 Bb7 220. Rd1 Ba8 221. Kc2 Bb7 222.
Kb1 Ba8 223. Ka2 Bb7 224. Ka3 Ba8 225. Ka4 Bb7 226. Ka5 Ba8 227. Kb6
h1=Q 228. Rxh1 Bg7 229. Rd1+ Bd4 230. Ka5 Bb7 231. Ka4 Ba8 232. Ka3 Bb7
233. Ka2 Ba8 234. Kb1 Bb7 235. Kc2 Ba8 236. Kd3 Bb7 237. Rf1 Ba8 238.
Re1 Bb7 239. Rd1 Ba8 240. Kc2 Bb7 241. Kb1 Ba8 242. Ka2 Bb7 243. Ka3 Ba8
244. Ka4 Bb7 245. Ka5 Ba8 246. Kb6 h2 247. Ka5 Bb7 248. Ka4 Ba8 249. Ka3
Bb7 250. Ka2 Ba8 251. Kb1 Bb7 252. Kc2 Ba8 253. Kd3 Bb7 254. Rf1 Ba8
255. Re1 Bb7 256. Rd1 Ba8 257. Kc2 Bb7 258. Kb1 Ba8 259. Ka2 Bb7 260.
Ka3 Ba8 261. Ka4 Bb7 262. Ka5 Ba8 263. Kb6 h1=Q 264. Rxh1 Bg7 265. Rd1+
Bd4 266. Ka5 Bb7 267. Ka4 Ba8 268. Ka3 Bb7 269. Ka2 Ba8 270. Kb1 Bb7
271. Kc2 Ba8 272. Kd3 Bb7 273. Rf1 Ba8 274. Re1 Bb7 275. Rd1 Ba8 276.
Kc2 Bb7 277. Kb1 Ba8 278. Ka2 Bb7 279. Ka3 Ba8 280. Ka4 Bb7 281. Ka5 Ba8
282. Kb6 Bb7 283. Kxb7 b1=Q 284. Rxb1 Be5 285. Rd1+ Bd4 286. Rxd4+ cxd4
287. Kb6 d3 288. a8=Q Rxb8+ 289. Qxb8 dxe2 290. Qxd8#

Youtube video of the solution

P.S. I thought that was the record, but when searching on the web this weekend I found this Level 292 problem (which is also an illegal position):

[Event "?"]
[Site "?"]
[Date "2018.04.14"]
[Round "?"]
[White "Blathy"]
[Black "Mate in 292"]
[Result "1-0"]
[Annotator "Dell"]
[SetUp "1"]
[FEN "q5nn/1p2p3/p1k1P1p1/6Pp/PKp1p1pP/8/2P1P1PP/3Q4 w - - 0 1"]
[PlyCount "583"]
[EventDate "2018.??.??"]

1. Qd7+ Kb6 2. a5+ Ka7 3. Qd4+ Kb8 4. Qd8+ Ka7 5. Qb6+ Kb8 6. c3 Kc8 7. Qc5+
Kb8 8. Qe5+ Kc8 9. Qd5 Kc7 10. Qd7+ Kb8 11. Qd8+ Ka7 12. Qb6+ Kb8 13. e3 Kc8
14. Qc5+ Kb8 15. Qe5+ Kc8 16. Qd5 Kc7 17. Qd7+ Kb8 18. Qd8+ Ka7 19. Qb6+ Kb8
20. g3 Kc8 21. Qc5+ Kb8 22. Qe5+ Kc8 23. Qd5 Kc7 24. Qd7+ Kb8 25. Qd8+ Ka7 26.
Qb6+ Kb8 27. Ka3 Kc8 28. Qc5+ Kb8 29. Qe5+ Kc8 30. Qd5 Kc7 31. Qd7+ Kb8 32.
Qd8+ Ka7 33. Qb6+ Kb8 34. Kb2 Kc8 35. Qc5+ Kb8 36. Qe5+ Kc8 37. Qd5 Kc7 38.
Qd7+ Kb8 39. Qd8+ Ka7 40. Qb6+ Kb8 41. Kc2 Kc8 42. Qc5+ Kb8 43. Qe5+ Kc8 44.
Qd5 Kc7 45. Qd7+ Kb8 46. Qd8+ Ka7 47. Qb6+ Kb8 48. Kd2 Kc8 49. Qc5+ Kb8 50.
Qe5+ Kc8 51. Qd5 Kc7 52. Qd7+ Kb8 53. Qd8+ Ka7 54. Qb6+ Kb8 55. Ke2 Kc8 56.
Qc5+ Kb8 57. Qe5+ Kc8 58. Qd5 Kc7 59. Qd7+ Kb8 60. Qd8+ Ka7 61. Qb6+ Kb8 62.
Kf2 Kc8 63. Qc5+ Kb8 64. Qe5+ Kc8 65. Qd5 Kc7 66. Qd7+ Kb8 67. Qd8+ Ka7 68.
Qb6+ Kb8 69. Kg2 Kc8 70. Qc5+ Kb8 71. Qe5+ Kc8 72. Qd5 Kc7 73. Qd7+ Kb8 74.
Qd8+ Ka7 75. Qb6+ Kb8 76. h3 gxh3+ 77. Kxh3 Kc8 78. Qc5+ Kb8 79. Qe5+ Kc8 80.
Qd5 Kc7 81. Qd7+ Kb8 82. Qd8+ Ka7 83. Qb6+ Kb8 84. Kg2 Kc8 85. Qc5+ Kb8 86.
Qe5+ Kc8 87. Qd5 Kc7 88. Qd7+ Kb8 89. Qd8+ Ka7 90. Qb6+ Kb8 91. Kf2 Kc8 92.
Qc5+ Kb8 93. Qe5+ Kc8 94. Qd5 Kc7 95. Qd7+ Kb8 96. Qd8+ Ka7 97. Qb6+ Kb8 98.
Ke2 Kc8 99. Qc5+ Kb8 100. Qe5+ Kc8 101. Qd5 Kc7 102. Qd7+ Kb8 103. Qd8+ Ka7
104. Qb6+ Kb8 105. Kd2 Kc8 106. Qc5+ Kb8 107. Qe5+ Kc8 108. Qd5 Kc7 109. Qd7+
Kb8 110. Qd8+ Ka7 111. Qb6+ Kb8 112. Kc2 Kc8 113. Qc5+ Kb8 114. Qe5+ Kc8 115.
Qd5 Kc7 116. Qd7+ Kb8 117. Qd8+ Ka7 118. Qb6+ Kb8 119. Kb2 Kc8 120. Qc5+ Kb8
121. Qe5+ Kc8 122. Qd5 Kc7 123. Qd7+ Kb8 124. Qd8+ Ka7 125. Qb6+ Kb8 126. Ka3
Kc8 127. Qc5+ Kb8 128. Qe5+ Kc8 129. Qd5 Kc7 130. Qd7+ Kb8 131. Qd8+ Ka7 132.
Qb6+ Kb8 133. Kb4 Kc8 134. Qc5+ Kb8 135. Qe5+ Ka7 136. Qd4+ Kb8 137. Qxh8 Kc7
138. Qe5+ Kc8 139. Qd5 Kb8 140. Qd8+ Ka7 141. Qb6+ Kb8 142. Ka3 Kc8 143. Qc5+
Kb8 144. Qe5+ Kc8 145. Qd5 Kc7 146. Qd7+ Kb8 147. Qd8+ Ka7 148. Qb6+ Kb8 149.
Kb2 Kc8 150. Qc5+ Kb8 151. Qe5+ Kc8 152. Qd5 Kc7 153. Qd7+ Kb8 154. Qd8+ Ka7
155. Qb6+ Kb8 156. Kc2 Kc8 157. Qc5+ Kb8 158. Qe5+ Kc8 159. Qd5 Kc7 160. Qd7+
Kb8 161. Qd8+ Ka7 162. Qb6+ Kb8 163. Kd2 Kc8 164. Qc5+ Kb8 165. Qe5+ Kc8 166.
Qd5 Kc7 167. Qd7+ Kb8 168. Qd8+ Ka7 169. Qb6+ Kb8 170. Ke2 Kc8 171. Qc5+ Kb8
172. Qe5+ Kc8 173. Qd5 Kc7 174. Qd7+ Kb8 175. Qd8+ Ka7 176. Qb6+ Kb8 177. Kf2
Kc8 178. Qc5+ Kb8 179. Qe5+ Kc8 180. Qd5 Kc7 181. Qd7+ Kb8 182. Qd8+ Ka7 183.
Qb6+ Kb8 184. Kg2 Kc8 185. Qc5+ Kb8 186. Qe5+ Kc8 187. Qd5 Kc7 188. Qd7+ Kb8
189. Qd8+ Ka7 190. Qb6+ Kb8 191. Kh3 Kc8 192. Qc5+ Kb8 193. Qe5+ Kc8 194. Qd5
Kc7 195. Qd7+ Kb8 196. Qd8+ Ka7 197. Qb6+ Kb8 198. g4 Kc8 199. Qc5+ Kb8 200.
Qe5+ Kc8 201. Qd5 Kc7 202. Qd7+ Kb8 203. Qd8+ Ka7 204. Qb6+ Kb8 205. gxh5 gxh5
206. Kg2 Kc8 207. Qc5+ Kb8 208. Qe5+ Kc8 209. Qd5 Kc7 210. Qd7+ Kb8 211. Qd8+
Ka7 212. Qb6+ Kb8 213. Kf2 Kc8 214. Qc5+ Kb8 215. Qe5+ Kc8 216. Qd5 Kc7 217.
Qd7+ Kb8 218. Qd8+ Ka7 219. Qb6+ Kb8 220. Ke2 Kc8 221. Qc5+ Kb8 222. Qe5+ Kc8
223. Qd5 Kc7 224. Qd7+ Kb8 225. Qd8+ Ka7 226. Qb6+ Kb8 227. Kd2 Kc8 228. Qc5+
Kb8 229. Qe5+ Kc8 230. Qd5 Kc7 231. Qd7+ Kb8 232. Qd8+ Ka7 233. Qb6+ Kb8 234.
Kc2 Kc8 235. Qc5+ Kb8 236. Qe5+ Kc8 237. Qd5 Kc7 238. Qd7+ Kb8 239. Qd8+ Ka7
240. Qb6+ Kb8 241. Kb2 Kc8 242. Qc5+ Kb8 243. Qe5+ Kc8 244. Qd5 Kc7 245. Qd7+
Kb8 246. Qd8+ Ka7 247. Qb6+ Kb8 248. Ka3 Kc8 249. Qc5+ Kb8 250. Qe5+ Kc8 251.
Qd5 Kc7 252. Qd7+ Kb8 253. Qd8+ Ka7 254. Qb6+ Kb8 255. Kb4 Kc8 256. Qc5+ Kb8
257. Kxc4 Qa7 258. Qxa7+ Kxa7 259. Kc5 b6+ 260. axb6+ Kb7 261. c4 a5 262. Kb5
a4 263. Kxa4 Kxb6 264. Kb4 Kc6 265. c5 Kd5 266. Kb5 Kxe6 267. Kc6 Kf7 268. Kd7
e5 269. c6 Ne7 270. c7 Nd5 271. c8=Q Nb6+ 272. Kd8 Nxc8 273. Kxc8 Ke8 274. Kc7
Ke7 275. Kc6 Ke6 276. Kc5 Ke7 277. Kd5 Kf7 278. Kxe5 Kg7 279. Kxe4 Kg6 280. Kf4
Kf7 281. Kf5 Kg7 282. e4 Kf7 283. g6+ Ke7 284. e5 Kf8 285. e6 Ke7 286. g7 Kd6
287. g8=Q Kc5 288. e7 Kd4 289. e8=Q Kc5 290. Qe5+ Kb4 291. Qgb8+ Kc4 292. Qbb5#

The longest in a legal position I thought was a 226-mover, sent to me by David Beckwith, but apparently some computer has found a Level-524">http://www.youtube.com/watch?v=wxIaMcO2amE]Level-524 puzzle... I expect only a computer could invent or solve that one!