There are complete (or nearly complete) six man end game table bases available for download, and even online.

What is the status of seven man table bases? Is there still active development in this area? How much progress has been made? Is there any estimated time for when it will be completed, or at least complete enough to cover all the common seven man positions that occur in real games?

  • 4
    If I could +1 this more than once I would. – Eve Freeman May 10 '12 at 22:35
  • So games like the ones shown below do not allow a win due to the 50 move rule. Will the rules be changed? Does anyone think a person could play those 'required' moves? Would the game be improved? If the game is so played-out that these measures are necessary, I'd sooner adopt FischerRandom/Chess360(?) to add some life. How to avoid made-in-500? Make the game more complex so one person is likely to be terminally outwitted before we all die of old age. That being said, I do like the technical achievement of a 7-man tablebase... – Tony Ennis Feb 9 '13 at 14:50
  • There used to be a 75-move exception for a few endgames that were known to take more than 50 to win; it was precisely the discovery of an endless list of endgames that take much longer that that was considered useless, and now we have a normal 50 move rule again. Also, Chess360 and the like differ in the opening but are exactly the same in the endgame, so the same things apply. Luckily, all of this is completely irrelevant to human vs human chess, noone will memorize 140 terabyte worth of tablebases. – RemcoGerlich Feb 12 '14 at 18:21

Seven man end game table bases are already available online:


By the end of 2013 they should be available off line as well. The size is 140 000 gigabytes so there is an obvious problem with copying them. They did not compute 6 white pieces versus 1 king since they decided it was pointless.

Interesting fact- the longest forced checkmate is 545 moves!

  • 3
    Heh, the longest known forced mate may be 545 moves, but I bet it gets longer with each tablebase iteration. – Tony Ennis Jul 19 '15 at 15:58

In the second link from Wes' answer, the joint work of Yakov Konoval and Marc Bourzutschky is mentioned in passing, though not described at all, so I thought I'd give them a shout out here, as they have done a lot of work in particular 7-man endgames. This includes impressive work on pawnless endings, such as showing that in this position, where it is Black to move, White wins in 330 moves with best play:

[FEN "1k6/1b5q/N7/8/8/1Q6/8/B1K5 b - - 0 1"]

1...Ka8 2.Nb4! Qh1+ 3.Kb2! Qg1 4.Qa4+! Qa7 5.Qe8+! Qb8 6.Qe1 Bf3 7.Kb1! Qf4 8.Qe8+! Qb8 9.Qe7 Qf4 10.Qd8+ Qb8 11.Qd2 Be4+ 12.Kc1! Qg3 13.Qd4! Qf4+ 14.Kb2! Qf3 15.Qd8+ Kb7 16.Qe7+! Ka8 17.Qe8+ Ka7 18.Qe5 Kb6 19.Ka2! Qf7+ 20.Ka3 Qa7+ 21.Kb2 Bh7 22.Qf6+! Kb5 23.Nd5! Ka5 24.Qc3+ Kb5 25.Nc7+ Kb6 26.Ne6 Qa5 27.Qe3+! Kb5 28.Nd4+ Kc4 29.Nb3! Qd5 30.Qc3+ Kb5 31.Qa5+! Kc6 32.Qa8+! Kd6 33.Qf8+ Kc7 34.Qg7+ Qd7 35.Qg1 Qe7 36.Ka2! Qe2+ 37.Bb2! Qa6+ 38.Ba3! Qe2+ 39.Ka1 Qd3 40.Qc1+! Kd8 41.Nc5! Qd5 42.Na4! Qd4+ 43.Nc3! Kd7 44.Qe1! Bg8 45.Qe7+! Kc6 46.Bb2 Bc4 47.Nb1! Qd6 48.Qe4+ Qd5 49.Qe8+! Qd7 50.Qe1 Qd3 51.Qh1+ Bd5 52.Qh6+! Kd7 53.Qg7+! Kc6 54.Qf6+ Kb7 55.Qe7+ Kc6 56.Bc3 Be4 57.Qe6+ Kc5 58.Qc8+ Kb6 59.Nd2 Bf5 60.Qb8+! Kc6 61.Qa8+! Kc5 62.Qa7+ Kc6 63.Qa4+ Qb5 64.Qa8+ Kd7 65.Qf3 Qa4+ 66.Kb2 Qc2+ 67.Ka3! Be6 68.Qb7+! Ke8 69.Qa8+ Kf7 70.Qf3+ Ke8 71.Qe3 Qa2+ 72.Kb4 Qd5 73.Be5! Qc6 74.Bd4 Kd7 75.Bc5! Qd5 76.Kc3! Qa2 77.Qe4 Qa5+ 78.Bb4! Qd5 79.Qh7+ Bf7 80.Qg7 Qa2 81.Qd4+ Qd5 82.Qa7+ Kc8 83.Qa6+ Kc7 84.Ba5+ Kb8 85.Qb6+ Ka8 86.Qc7 Qb7 87.Qc5 Bd5 88.Qf8+ Qb8 89.Qf5 Qd6 90.Bb4 Qc6+ 91.Kb2 Be6 92.Qa5+ Kb7 93.Bc5 Qa6 94.Qc3 Qc6 95.Qb4+ Ka6 96.Qa3+ Kb7 97.Bg1 Kc7 98.Qe7+ Qd7 99.Qb4 Qd5 100.Kc1 Qc6+ 101.Kd1! Kd7 102.Qd4+ Qd5 103.Qa7+ Kc8 104.Qa4 Qe5 105.Bb6 Qh5+ 106.Kc1 Qe5 107.Bf2 Bd5 108.Qa6+ Kd8 109.Qa3 Kd7 110.Qd3 Qc7+ 111.Kd1 Qd6 112.Bg3 Qc6 113.Qd4 Ke6 114.Bf4 Kf7 115.Be5 Ke6 116.Bh8 Ke7 117.Qb4+ Ke8 118.Be5 Qb7 119.Qc5 Qc6 120.Qa3 Qh6 121.Bc3 Qc6 122.Qa5 Kd7 123.Kc1 Be6 124.Qe5 Qh1+ 125.Kc2 Qd5 126.Qg7+ Bf7 127.Qg3 Qd6 128.Qe3 Bd5 129.Kd1 Qe6 130.Qd4 Kc8 131.Qh8+ Qg8 132.Qf6 Qg4+ 133.Kc1 Qe6 134.Qf8+ Kb7 135.Nf1 Qe4 136.Qc5 Qc4 137.Qe7+! Qc7 138.Qb4+ Qb6 139.Qf8 Qg1 140.Qe7+ Kc6 141.Qf6+ Kd7 142.Kc2 Qg2+ 143.Nd2 Be6 144.Qh6 Qd5 145.Kd1 Qc5 146.Qg7+ Ke8 147.Kc2 Qf5+ 148.Kc1 Qc5 149.Qg6+ Kd7 150.Qd3+ Qd6 151.Qe4 Qa3+ 152.Kc2! Qa2+ 153.Kd1 Qd5 154.Qe3 Qd6 155.Qa7+ Qc7 156.Qd4+ Qd6 157.Qg7+ Qe7 158.Qg1 Kc8 159.Qg6 Qd6 160.Qg7 Qf4 161.Kc1 Qe3 162.Qf6 Kd7 163.Bb4 Kc8 164.Kc2 Kb7 165.Bc3 Bd5 166.Be5 Qc5+ 167.Kd1 Kc8 168.Qf5+ Kd8 169.Nf1 Qg1 170.Bf6+ Kc7 171.Kd2! Qg2+ 172.Ke3! Bc6 173.Nd2! Qg3+ 174.Ke2 Qh2+ 175.Kd1 Qh1+ 176.Kc2 Qd5 177.Qf4+ Kc8 178.Bd4 Qe6 179.Kd1 Bd5 180.Be5 Qb6 181.Qf5+ Qe6 182.Qg5 Qg8 183.Qf4 Qg1+ 184.Ke2 Qg2+ 185.Kd3 Qg6+ 186.Kd4 Bf7 187.Ne4 Qg1+ 188.Kd3 Qd1+ 189.Ke3 Qe1+ 190.Kf3 Qf1+ 191.Nf2! Qc4 192.Qf6 Qe6 193.Qh8+! Qe8 194.Qg7 Qd8 195.Ke2! Qe7 196.Qh8+ Qe8 197.Qh3+ Qe6 198.Qe3! Qb3 199.Qc5+! Kb7 200.Qe7+! Ka6 201.Kd2! Bg6 202.Qc5 Qb6 203.Qc4+! Qb5 204.Qc8+ Qb7 205.Qc3 Qd5+ 206.Ke3! Kb5 207.Qb2+! Kc6 208.Kf4! Qc4+ 209.Kg3! Bc2 210.Kh2 Kd7 211.Qb7+ Ke6 212.Bg3! Bf5 213.Qg7! Qc8 214.Bh4 Qb8+ 215.Kg1 Qe5 216.Qe7+ Kd5 217.Qf7+ Kc6 218.Qb3 Qd4 219.Bg3 Bd7 220.Qb1 Be6 221.Qg6 Kd7 222.Qh7+ Kc6 223.Qc7+ Kb5 224.Qb7+! Qb6 225.Qe4 Bb3 226.Bf4 Qc6 227.Qh7 Qf3 228.Qd7+! Qc6 229.Qg7 Qc5 230.Kg2 Be6 231.Qb2+ Kc6 232.Qe2 Bf5 233.Qe8+ Kb7 234.Kg3 Qc3+ 235.Kh2! Qf6 236.Qb8+ Kc6 237.Qc7+ Kd5 238.Kg1! Qg6+ 239.Bg3! Qf6 240.Qc1 Qd4 241.Qh6 Bd7 242.Qa6 Bc6 243.Qe2 Kc5 244.Be5 Qc4 245.Nd3+! Kb5 246.Qb2+! Ka4 247.Nf4 Qb3 248.Qd4+ Qb4 249.Qa1+ Qa3 250.Qe1 Qf3 251.Kh2! Bb7 252.Qd2 Kb5 253.Bf6 Ka6 254.Be7 Bc6 255.Bc5 Kb7 256.Qb2+ Kc8 257.Qf6 Kb7 258.Qe7+ Kc8 259.Qd6 Kb7 260.Bd4 Ka6 261.Qc7 Kb5 262.Qb6+ Kc4 263.Be3 Kc3 264.Qd4+ Kb3 265.Qd3+ Ka4 266.Qc4+ Ka5 267.Bc5 Qe4 268.Qc3+ Kb5 269.Bd6 Qc4 270.Qe3 Bd7 271.Qd2 Bc6 272.Kh3 Ka6 273.Be5 Bb5 274.Bd4 Qf7 275.Kg3 Qg8+ 276.Kf3 Qb3+ 277.Be3 Kb7 278.Kf2 Kc8 279.Qd6 Qa2+ 280.Kf3 Qc4 281.Qf8+ Kb7 282.Kg3 Qc7 283.Qh8 Qe7 284.Qd4 Qg5+ 285.Kf3 Qf5 286.Qb6+ Kc8 287.Bd4 Qd7 288.Kg3 Qc6 289.Qa7 Qb7 290.Qc5+ Qc6 291.Qf5+ Qd7 292.Qe5 Qe8 293.Ne6 Qg6+ 294.Kf3 Qd3+ 295.Kf4 Qd2+ 296.Kg3! Qd3+ 297.Be3 Qg6+ 298.Ng5 Qe8 299.Qd4 Qd7 300.Qb4 Qd5 301.Bf4 Bc6 302.Qf8+ Kd7 303.Qg7+ Ke8 304.Qc7 Qg2+ 305.Kh4 Qh1+ 306.Bh2 Qd5 307.Kh5 Bd7 308.Bd6 Qh1+ 309.Kg6 Qc6 310. Qb8+! Bc8 311.Qb4! Qd5 312.Qb6 Qf5+ 313.Kh5! Qg4+ 314.Kh6 Qh4+ 315.Kg6! Qc4 316.Kf6 Qf1+ 317.Kg7! Qf5 318.Qe3+! Kd7 319.Nf7 Kc6 320.Qc1+ Kb5 321.Ne5 Be6 322.Qc6+ Ka5 323.Qa8+ Kb6 324.Qb8+ Ka6 325.Bc7 Qg5+ 326.Ng6! Qe3 327.Qa8+ Kb5 328.Qe8+ Ka6 329.Kf6 Qc3+ 330.Be5!

I'm sure that appears complicated enough, but to really get a sense as to how complicated the optimal play is from the initial position, note that every move annotated with ! above is an only-winning move, i.e. any other move would allow a draw against best play from Black.

They later showed that this position - again with Black to move and with ! indicating an only-winning move - is a win for White in 517 moves:

[FEN "8/1r6/8/6n1/5k2/1b6/3K3N/7Q b - - 0 1"]

1...Rd7+ 2.Kc3! Bd1 3.Qf1+! Bf3 4.Qc1+! Kf5 5.Kb2! Rb7+ 6.Ka3 Ra7+ 7.Kb4 Rb7+ 8.Ka5 Ra7+ 9.Kb6 Rb7+ 10.Ka6 Re7 11.Qf1 Re6+ 12.Ka7 Re7+ 13.Kb8 Re8+ 14.Kc7 Re3 15.Kc8 Rc3+ 16.Kb8! Kf4 17.Qg1! Ne4 18.Nf1! Rb3+ 19.Ka7! Rd3 20.Qh2+! Kf5 21.Kb8 Nf6 22.Nd2! Bd5 23.Qf2+! Ke5 24.Qe2+ Kd4 25.Ka7 Nd7 26.Qg4+! Kc5 27.Qg1+! Kb4 28.Qb1+! Kc3 29.Qc1+ Kd4 30.Qb2+ Kc5 31.Qc2+! Kd4 32.Qa4+ Kc5 33.Qa5+ Kd4 34.Qb4+ Ke5 35.Ka6 Kf5 36.Qb1 Ne5 37.Kb5! Bc6+ 38.Kb4! Bd5 39.Qf1+ Kg6 40.Qe2 Kf6 41.Qh5 Ke6 42.Qg5 Nc6+ 43.Kb5 Ne5 44.Qh6+ Kf5 45.Nf1 Bc6+ 46.Kb4 Rd4+ 47.Kb3 Rd3+ 48.Ka2 Bd5+ 49.Kb1! Nc4 50.Qh5+! Kf6 51.Qh4+ Ke6 52.Ng3! Rb3+ 53.Kc1! Rc3+ 54.Kd1 Re3 55.Nf1! Ra3 56.Qf4 Kd7 57.Ke1 Kc6 58.Qh6+ Kc5 59.Kf2 Rb3 60.Qh8 Ra3 61.Qb8 Kc6 62.Qb1 Rc3 63.Kg1 Ra3 64.Qc2 Kb6 65.Qf5 Kc5 66.Qf8+ Kb5 67.Qe8+ Kc5 68.Qe2 Rf3 69.Qe7+ Kd4 70.Qg7+ Kc5 71.Qg5 Kc6 72.Qh4 Kb5 73.Qe7 Kb6 74.Qb4+ Kc6 75.Qe1 Ra3 76.Qf2 Rf3 77.Qd4 Kd6 78.Qh4 Kc5 79.Nh2 Ra3 80.Ng4 Ra1+ 81.Kf2! Ra2+ 82.Kg3! Ra3+ 83.Kf4 Rf3+ 84.Kg5 Be6 85.Nf6! Ne5 86.Nh5 Rf5+ 87.Kh6 Ng4+ 88.Kg6! Ne5+ 89.Kh7 Rf7+ 90.Kh6! Ng4+ 91.Kg5 Ne5 92.Qa4 Rf5+ 93.Kh6! Bc4 94.Qa5+ Kd4 95.Qb6+ Kd5 96.Qd8+ Ke4 97.Qd1 Ke3 98.Qc1+ Kd4 99.Ng3 Rf6+ 100.Kh5 Kd5 101.Kh4 Rg6 102.Kh3 Bd3 103.Qf4 Rg8 104.Qb4 Bc4 105.Qd2+ Ke6 106.Qh6+ Kd5 107.Qh7 Kc5 108.Kh2 Rg6 109.Qe7+ Kd5 110.Qd8+ Ke6 111.Qf8 Kd5 112.Kh3 Bb5 113.Qa3 Bc6 114.Kg2 Rf6 115.Kh2 Nf3+ 116.Kh3 Rh6+ 117.Kg2! Nd4 118.Qe7 Kc4+ 119.Kg1! Rg6 120.Qf7+ Re6 121.Qf4 Kd3 122.Qf1+ Kc3 123.Qc1+ Kb4 124.Kh2 Rf6 125.Kh3 Bd7+ 126.Kg2! Bc6+ 127.Kh2 Rf3 128.Qd1 Kc5 129.Nh5 Kd5 130.Qh1 Ke6 131.Qg1 Ke5 132.Qg7+ Ke4 133.Qc7 Kd5 134.Nf4+ Kc4 135.Qb8 Rc3 136.Qa7 Be4 137.Qb6 Bc6 138.Qa6+ Kc5 139.Nd3+ Kd6 140.Nb2 Rb3 141.Nd1 Nf3+ 142.Kg3 Nd4+ 143.Kf2 Rf3+ 144.Ke1 Kd5 145.Qb6 Kc4 146.Qa7 Bb5 147.Nf2 Nc2+ 148.Kf1 Bc6 149.Qa6+ Kc5 150.Qa2 Nd4 151.Kg1! Rf5 152.Kh2 Rh5+ 153.Kg3! Rg5+ 154.Kf4! Rf5+ 155.Kg4 Bf3+ 156.Kh4 Rh5+ 157.Kg3 Rg5+ 158.Kf4 Rf5+ 159.Ke3! Re5+ 160.Kd3 Be2+ 161.Kd2! Kb4 162.Qg8 Bb5 163.Qg4 Re2+ 164.Kc1! Kc4 165.Nd1! Rc2+ 166.Kb1 Rd2 167.Qc8+ Bc6 168.Qg8+! Kb4 169.Nb2 Be4+ 170.Ka2! Nb5 171.Qb3+! Ka5 172.Ka1! Bd5 173.Qa4+! Kb6 174.Qb4! Rd4 175.Qe1 Be4 176.Nd1 Rc4 177.Qe3+ Kc6 178.Kb2 Rc2+ 179.Kb3 Nd6 180.Qh6 Rc5 181.Nc3 Bd5+ 182.Kc2 Kd7 183.Qg7+ Kc6 184.Kd1 Bf7 185.Kd2 Bc4 186.Ke1 Ra5 187.Qf6 Rf5 188.Qg6 Kc7 189.Qg7+ Rf7 190.Qg3 Kc6 191.Qg2+ Kc7 192.Qh2 Kc6 193.Qh1+ Kc5 194.Qh8 Re7+ 195.Kd1! Re8 196.Qh2 Re3 197.Kc2 Rd3 198.Qe5+ Kc6 199.Qh5 Rg3 200.Qa5 Rh3 201.Kd2 Rh2+ 202.Ke3 Rh3+ 203.Kf4 Rd3 204.Na4 Rd4+ 205.Kf3 Rd3+ 206.Kg4 Rd4+ 207.Kh3 Ne4 208.Qa7 Be6+ 209.Kg2! Rb4 210.Qa6+! Kd5 211.Kf3 Kd4 212.Qe2 Kd5 213.Ke3 Bd7 214.Nb2 Bb5 215.Qh5+ Ke6 216.Nd1 Nf6 217.Qh3+ Kf7 218.Kd2 Rd4+ 219.Kc1 Rc4+ 220.Kb2 Rb4+ 221.Ka3 Ra4+ 222.Kb3 Rd4 223.Nc3 Bc4+ 224.Kc2! Be6 225.Qe3 Rh4 226.Qa7+ Kg6 227.Ne2 Rb4 228.Kc1 Rc4+ 229.Kb2 Rb4+ 230.Ka3 Rb3+ 231.Ka4! Rf3 232.Qd4 Bd7+ 233.Kb4 Be6 234.Qc5 Bd7 235.Qd6 Bg4 236.Nd4 Rd3 237.Kc4 Re3 238.Nc6 Bc8 239.Qh2 Re4+ 240.Kc5 Bb7 241.Qg1+ Kh7 242.Na7 Rg4 243.Qh2+ Kg6 244.Nb5 Rg2 245.Qh3 Rg5+ 246.Kb4 Bg2 247.Qh2 Bd5 248.Nd6 Ne4 249.Nc8 Nf6 250.Qd6 Rh5 251.Qc7 Kg5 252.Qe5+ Kg6 253.Qe3 Kh7 254.Qd3+ Kg7 255.Nd6 Rg5 256.Ka4 Rh5 257.Qg3+ Kh7 258.Kb4 Kh6 259.Ka3 Rg5 260.Qc3 Kg6 261.Qc2+ Kh6 262.Nf5+ Kh5 263.Qd3 Kg6 264.Ng3+ Kf7 265.Qe3 Rg8 266.Nf5 Ra8+ 267.Kb2! Ra2+ 268.Kb1 Ra6 269.Qe7+ Kg6 270.Nd6 Rb6+ 271.Kc2 Rb3 272.Qe5 Rf3 273.Kd2 Bc6 274.Nc4 Bd5 275.Ne3 Be4 276.Ng4 Bb7 277.Qe6 Kg5 278.Ne5 Rf2+ 279.Kc3 Rf4 280.Nf7+ Kg6 281.Nd6 Be4 282.Kd2 Rf2+ 283.Ke1 Rf4 284.Qc4 Kg5 285.Qe2 Bg6 286.Qe5+ Kg4 287.Ke2 Bf5 288.Qa1 Nh5 289.Ke3 Bc2 290.Qa8 Bg6 291.Qd5 Ng3 292.Nc4 Nf5+ 293.Ke2! Ng3+ 294.Kd2 Kh3 295.Qc6 Re4 296.Qa6 Re2+ 297.Kc3 Be4 298.Qd6 Kg2 299.Kb4 Bf3 300.Ka5 Nf5 301.Qc5 Be4 302.Kb6 Rc2 303.Qb4 Kf2 304.Ne5 Ke3 305.Nd7 Nd4 306.Qa3+ Ke2 307.Ne5 Nf5 308.Qa6+ Kf2 309.Qa4 Ng3 310.Qb4 Ke3 311.Nc4+ Kd3 312.Nd6 Ke3 313.Ka7 Bd3 314.Qb6+ Kf3 315.Qd4 Be4 316.Kb8 Re2 317.Nf7 Bf5 318.Ng5+ Kg2 319.Qd5+ Be4 320.Qb3 Bf5 321.Qf3+ Kh2 322.Qb7 Re8+ 323.Ka7! Re2 324.Qd5 Rf2 325.Nf3+ Kg2 326.Nd2+ Kh3 327.Qc6 Kg4 328.Qc3 Rf4 329.Nc4 Re4 330.Ne3+ Kg5 331.Qc5 Re6 332.Kb8 Re8+ 333.Kb7 Re6 334.Kc7 Re4 335.Kc6 Re8 336.Kb6 Re4 337.Ka5 Re6 338.Kb5 Re4 339.Nd5 Nh5 340.Ne7 Ng3 341.Qc1+ Kh4 342.Qh6+ Kg4 343.Nd5 Kf3 344.Qf6 Kg4 345.Qg7+ Kf3 346.Qc3+ Kf2 347.Qc5+ Kf3 348.Ka5 Bg4 349.Nf6 Rf4 350.Qc6+ Kf2 351.Nd5 Re4 352.Qf6+ Bf3 353.Nf4 Ne2 354.Nd3+ Ke3 355.Ne5 Rf4 356.Qb6+ Nd4 357.Kb4 Ke4 358.Nc4 Kf5 359.Qh6 Be2 360.Ne3+ Ke5 361.Qh8+ Ke4 362.Qe8+! Kf3 363.Nd5! Re4 364.Qf7+ Kg3 365.Qg6+ Kf3 366.Nf6 Rf4 367.Qh5+ Kg3 368.Qg5+ Kf3 369.Kc3 Nb5+ 370.Kb3! Rc4 371.Nd5 Nd4+ 372.Kb2 Rc2+ 373.Kb1 Ke4 374.Nf6+ Kd3 375.Nd7 Bf3 376.Ne5+ Ke2 377.Qh4 Rd2 378.Nc4! Rd1+ 379.Kb2! Rd3 380.Qg5 Rb3+ 381.Ka2! Rd3 382.Qe5+ Kf2 383.Nb2 Rd2 384.Qf4 Ke2 385.Kb1 Bg2 386.Nc4 Rd3 387.Qh2 Kf1 388.Qh7 Rc3 389.Kb2 Rc2+ 390.Ka3 Rc3+ 391.Kb4 Ne2 392.Ne5 Rh3 393.Qf5+ Ke1 394.Nd3+ Kd2 395.Nc5 Rg3 396.Qh7 Ke3 397.Qd3+ Kf2 398.Qc4 Rc3 399.Qh4+ Rg3 400.Ka5 Kg1 401.Qe7 Kf2 402.Qf6+ Ke1 403.Qh4 Kf1 404.Qd8 Ke1 405.Nd3+ Kd2 406.Nb4+ Kc1 407.Qe7 Kd2 408.Qd6+ Ke3 409.Nc2+ Kf2 410.Qe7 Rf3 411.Qh4+ Rg3 412.Ka6 Bh3 413.Qf6+ Rf3 414.Qa1 Rd3 415.Qe1+ Kf3 416.Qb4 Kg3 417.Qe7 Kf2 418.Ka5 Rc3 419.Qf8+ Rf3 420.Qb4 Rc3 421.Qb6+ Kg3 422.Ne3 Nf4 423.Nc4 Rf3 424.Qc7 Rf2 425.Qg7+ Kh2 426.Qe5 Kg3 427.Qg5+ Kh2 428.Kb6 Bg2 429.Ne3 Bh3 430.Qe5 Kg3 431.Nd5 Kg4 432.Qd4 Kg3 433.Qe3+ Rf3 434.Qe5 Kg4 435.Nf6+ Kg3 436.Ne4+ Kg2 437.Qc5 Ne2 438.Qc4 Nf4 439.Qc2+ Kh1 440.Qc5 Bg2 441.Nf2+ Kh2 442.Ng4+ Kh3 443.Qg5 Rb3+ 444.Ka5 Ra3+ 445.Kb4 Rf3 446.Ne5 Nd5+ 447.Kb5 Rf4 448.Kc5 Be4 449.Nc6 Rh4 450.Qd2 Kg4 451.Qe1 Bg2 452.Qe6+ Kg3 453.Nd4 Nf4 454.Qb3+ Kh2 455.Qe3 Rh5+ 456.Kd6! Rd5+ 457.Ke7! Nh3 458.Qd2 Kg3 459.Qc3+ Kh2 460.Qe3 Rg5 461.Qe2 Nf4 462.Qf2 Rg4 463.Nf5 Nd5+ 464.Ke6 Rg6+ 465.Kd7 Rg4 466.Qe1 Nf6+ 467.Kc7 Ne4 468.Qc1 Rg5 469.Qf4+! Kg1 470.Ne3 Rg7+ 471.Kb6 Rg6+ 472.Ka5 Rg5+ 473.Kb4 Rg6 474.Qe5 Bf3 475.Qa1+ Kh2 476.Qb2+ Kh1 477.Qc1+ Rg1 478.Qc8 Rg3 479.Qh8+ Kg1 480.Qa1+ Kf2 481.Qd4 Rg5 482.Nf5+ Kg2 483.Qb2+ Kh3 484.Ne3 Rh5 485.Nf1 Kg4 486.Qg7+ Kh3 487.Qg1 Rh4 488.Ka3 Rf4 489.Qh2+ Kg4 490.Ne3+ Kg5 491.Nd5 Rf7 492.Qe5+ Kh4 493.Ne7 Ng5 494.Ng8 Ne4 495.Nh6 Rf6 496.Nf5+ Kg4 497.Ne3+ Kh4 498.Kb4 Rb6+ 499.Ka5 Rf6 500.Qh2+ Kg5 501.Qh7 Ng3 502.Qg7+ Rg6 503.Qe5+ Kh6 504.Qf4+ Rg5+ 505.Kb6 Be2 506.Qf8+ Kh7 507.Nd5 Bc4 508.Nf6+ Kg6 509.Nd7 Nh5 510.Qd6+ Kh7 511.Qe7+ Kh6 512.Qe3 Be6 513.Ne5 Bd5 514.Qd4 Bg8 515.Qd2 Nf6 516.Nf3 Nd5+ 517.Kb7 Kg7 518.Qxg5+

Note: "win for white in X moves" here means that, assuming perfect play, it will take X moves for white to reduce the position to a won 6 piece endgame (for which there are complete tablebases available). It doesn't mean it's X moves until mate. So in the longer example here, for instance, no capture is made until exactly move 517, when a winning 6 piece endgame is reached.

In a post from 2006, Bourzutschky himself gives an account of some of their work involving 7-man endings with pawns.

  • 1
    That is pretty neat--do the 330/517 moves obey the 50 move rule? – Eve Freeman Jul 20 '12 at 17:57
  • 1
    @WesFreeman, The numbers here (e.g. the 517 moves) in fact refer not to how far off mate is, but rather to how long it takes the stronger side to reduce to a winning 6 piece endgame. So if you follow the link to Tim Krabbe's site, for example, you'll see that the only capture occurs at the final move 517, bringing the position to a won 6-piecer. Thus the initial position would be drawn by the 50-move rule (by quite a margin in fact!) with perfect play. Thanks for the comment; I'm now going to clarify what is meant by "wins in X moves" in this answer. – ETD Jul 20 '12 at 18:21
  • 1
    this answer actually exposes some rather serious problems with the player: 1. try jumping between different phases of the game by clicking on the moves 2. the animation appears to be asynchronous? – prusswan Nov 14 '12 at 18:21
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    @prusswan, I agree completely, the particular method of animation that's used in the player doesn't work very well when jumping as many moves forward/backward as one can in these absurdly long move lists, as you can be left sitting and waiting for a bit of time. Of course, there will be very few 300-500 move games that get posted, and (IMHO) the animation looks nice when jumping around games of more typical length. But whether we generally want to have animation or not (or maybe have the option to turn it off) is definitely worth discussing on meta, if you'd like to get the ball rolling. – ETD Nov 14 '12 at 18:34
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    @prusswan that asynchronous movement was actually by-design in order to see how the pieces move for a short series of moves. I did remove the async animations when you click on moves in version 1.1.5 of the replayer though. – Andrew Nov 14 '12 at 18:54

I researched this some last summer, and found this post, which was inspiring because it was dated recently at the time.

The threads related saw a bit of activity and died off:

In short, I don't think we have any working 7-piece tablebases (complete ones, anyway), yet. They're going to be quite large and the current programs need to be rewritten to support these new larger files. APIs need to be rewritten as well.

  • Hopefully someone has a more complete answer, but my comment got quite long, so I decided to post it as an answer. – Eve Freeman May 10 '12 at 22:45

7-men syzygy tables are available for download: ftp://ftp.chessdb.cn/pub/syzygy/


As of August 2018, only latest development Stockfish (and some of its derivatives) supports them.

protected by Phonon Sep 19 '18 at 11:55

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