The array of 781 random numbers is of course taken from the Polyglot source code but I am pretty sure that a table of random numbers cannot be covered by copyright.

Look below for some sample code which is released in the public domain.

At the end of this document we discuss an extension of the Polyglot opening book format for Chess960. This extension is implemented in upcoming versions of xboard/winboard.

key uint64 move uint16 weight uint16 learn uint32

All integers are stored highest byte first (regardless of size)

The entries are ordered according to key. Lowest key first.

The starting point is given by the following declaration

#ifdef _MSC_VER # define U64(u) (u##ui64) #else # define U64(u) (u##ULL) #endif const uint64 Random64[781] = { U64(0x9D39247E33776D41), U64(0x2AF7398005AAA5C7), U64(0x44DB015024623547), U64(0x9C15F73E62A76AE2), U64(0x75834465489C0C89), U64(0x3290AC3A203001BF), U64(0x0FBBAD1F61042279), U64(0xE83A908FF2FB60CA), U64(0x0D7E765D58755C10), U64(0x1A083822CEAFE02D), U64(0x9605D5F0E25EC3B0), U64(0xD021FF5CD13A2ED5), U64(0x40BDF15D4A672E32), U64(0x011355146FD56395), U64(0x5DB4832046F3D9E5), U64(0x239F8B2D7FF719CC), U64(0x05D1A1AE85B49AA1), U64(0x679F848F6E8FC971), U64(0x7449BBFF801FED0B), U64(0x7D11CDB1C3B7ADF0), U64(0x82C7709E781EB7CC), U64(0xF3218F1C9510786C), U64(0x331478F3AF51BBE6), U64(0x4BB38DE5E7219443), U64(0xAA649C6EBCFD50FC), U64(0x8DBD98A352AFD40B), U64(0x87D2074B81D79217), U64(0x19F3C751D3E92AE1), U64(0xB4AB30F062B19ABF), U64(0x7B0500AC42047AC4), U64(0xC9452CA81A09D85D), U64(0x24AA6C514DA27500), U64(0x4C9F34427501B447), U64(0x14A68FD73C910841), U64(0xA71B9B83461CBD93), U64(0x03488B95B0F1850F), U64(0x637B2B34FF93C040), U64(0x09D1BC9A3DD90A94), U64(0x3575668334A1DD3B), U64(0x735E2B97A4C45A23), U64(0x18727070F1BD400B), U64(0x1FCBACD259BF02E7), U64(0xD310A7C2CE9B6555), U64(0xBF983FE0FE5D8244), U64(0x9F74D14F7454A824), U64(0x51EBDC4AB9BA3035), U64(0x5C82C505DB9AB0FA), U64(0xFCF7FE8A3430B241), U64(0x3253A729B9BA3DDE), U64(0x8C74C368081B3075), U64(0xB9BC6C87167C33E7), U64(0x7EF48F2B83024E20), U64(0x11D505D4C351BD7F), U64(0x6568FCA92C76A243), U64(0x4DE0B0F40F32A7B8), U64(0x96D693460CC37E5D), U64(0x42E240CB63689F2F), U64(0x6D2BDCDAE2919661), U64(0x42880B0236E4D951), U64(0x5F0F4A5898171BB6), U64(0x39F890F579F92F88), U64(0x93C5B5F47356388B), U64(0x63DC359D8D231B78), U64(0xEC16CA8AEA98AD76), U64(0x5355F900C2A82DC7), U64(0x07FB9F855A997142), U64(0x5093417AA8A7ED5E), U64(0x7BCBC38DA25A7F3C), U64(0x19FC8A768CF4B6D4), U64(0x637A7780DECFC0D9), U64(0x8249A47AEE0E41F7), U64(0x79AD695501E7D1E8), U64(0x14ACBAF4777D5776), U64(0xF145B6BECCDEA195), U64(0xDABF2AC8201752FC), U64(0x24C3C94DF9C8D3F6), U64(0xBB6E2924F03912EA), U64(0x0CE26C0B95C980D9), U64(0xA49CD132BFBF7CC4), U64(0xE99D662AF4243939), U64(0x27E6AD7891165C3F), U64(0x8535F040B9744FF1), U64(0x54B3F4FA5F40D873), U64(0x72B12C32127FED2B), U64(0xEE954D3C7B411F47), U64(0x9A85AC909A24EAA1), U64(0x70AC4CD9F04F21F5), U64(0xF9B89D3E99A075C2), U64(0x87B3E2B2B5C907B1), U64(0xA366E5B8C54F48B8), U64(0xAE4A9346CC3F7CF2), U64(0x1920C04D47267BBD), U64(0x87BF02C6B49E2AE9), U64(0x092237AC237F3859), U64(0xFF07F64EF8ED14D0), U64(0x8DE8DCA9F03CC54E), U64(0x9C1633264DB49C89), U64(0xB3F22C3D0B0B38ED), U64(0x390E5FB44D01144B), U64(0x5BFEA5B4712768E9), U64(0x1E1032911FA78984), U64(0x9A74ACB964E78CB3), U64(0x4F80F7A035DAFB04), U64(0x6304D09A0B3738C4), U64(0x2171E64683023A08), U64(0x5B9B63EB9CEFF80C), U64(0x506AACF489889342), U64(0x1881AFC9A3A701D6), U64(0x6503080440750644), U64(0xDFD395339CDBF4A7), U64(0xEF927DBCF00C20F2), U64(0x7B32F7D1E03680EC), U64(0xB9FD7620E7316243), U64(0x05A7E8A57DB91B77), U64(0xB5889C6E15630A75), U64(0x4A750A09CE9573F7), U64(0xCF464CEC899A2F8A), U64(0xF538639CE705B824), U64(0x3C79A0FF5580EF7F), U64(0xEDE6C87F8477609D), U64(0x799E81F05BC93F31), U64(0x86536B8CF3428A8C), U64(0x97D7374C60087B73), U64(0xA246637CFF328532), U64(0x043FCAE60CC0EBA0), U64(0x920E449535DD359E), U64(0x70EB093B15B290CC), U64(0x73A1921916591CBD), U64(0x56436C9FE1A1AA8D), U64(0xEFAC4B70633B8F81), U64(0xBB215798D45DF7AF), U64(0x45F20042F24F1768), U64(0x930F80F4E8EB7462), U64(0xFF6712FFCFD75EA1), U64(0xAE623FD67468AA70), U64(0xDD2C5BC84BC8D8FC), U64(0x7EED120D54CF2DD9), U64(0x22FE545401165F1C), U64(0xC91800E98FB99929), U64(0x808BD68E6AC10365), U64(0xDEC468145B7605F6), U64(0x1BEDE3A3AEF53302), U64(0x43539603D6C55602), U64(0xAA969B5C691CCB7A), U64(0xA87832D392EFEE56), U64(0x65942C7B3C7E11AE), U64(0xDED2D633CAD004F6), U64(0x21F08570F420E565), U64(0xB415938D7DA94E3C), U64(0x91B859E59ECB6350), U64(0x10CFF333E0ED804A), U64(0x28AED140BE0BB7DD), U64(0xC5CC1D89724FA456), U64(0x5648F680F11A2741), U64(0x2D255069F0B7DAB3), U64(0x9BC5A38EF729ABD4), U64(0xEF2F054308F6A2BC), U64(0xAF2042F5CC5C2858), U64(0x480412BAB7F5BE2A), U64(0xAEF3AF4A563DFE43), U64(0x19AFE59AE451497F), U64(0x52593803DFF1E840), U64(0xF4F076E65F2CE6F0), U64(0x11379625747D5AF3), U64(0xBCE5D2248682C115), U64(0x9DA4243DE836994F), U64(0x066F70B33FE09017), U64(0x4DC4DE189B671A1C), U64(0x51039AB7712457C3), U64(0xC07A3F80C31FB4B4), U64(0xB46EE9C5E64A6E7C), U64(0xB3819A42ABE61C87), U64(0x21A007933A522A20), U64(0x2DF16F761598AA4F), U64(0x763C4A1371B368FD), U64(0xF793C46702E086A0), U64(0xD7288E012AEB8D31), U64(0xDE336A2A4BC1C44B), U64(0x0BF692B38D079F23), U64(0x2C604A7A177326B3), U64(0x4850E73E03EB6064), U64(0xCFC447F1E53C8E1B), U64(0xB05CA3F564268D99), U64(0x9AE182C8BC9474E8), U64(0xA4FC4BD4FC5558CA), U64(0xE755178D58FC4E76), U64(0x69B97DB1A4C03DFE), U64(0xF9B5B7C4ACC67C96), U64(0xFC6A82D64B8655FB), U64(0x9C684CB6C4D24417), U64(0x8EC97D2917456ED0), U64(0x6703DF9D2924E97E), U64(0xC547F57E42A7444E), U64(0x78E37644E7CAD29E), U64(0xFE9A44E9362F05FA), U64(0x08BD35CC38336615), U64(0x9315E5EB3A129ACE), U64(0x94061B871E04DF75), U64(0xDF1D9F9D784BA010), U64(0x3BBA57B68871B59D), U64(0xD2B7ADEEDED1F73F), U64(0xF7A255D83BC373F8), U64(0xD7F4F2448C0CEB81), U64(0xD95BE88CD210FFA7), U64(0x336F52F8FF4728E7), U64(0xA74049DAC312AC71), U64(0xA2F61BB6E437FDB5), U64(0x4F2A5CB07F6A35B3), U64(0x87D380BDA5BF7859), U64(0x16B9F7E06C453A21), U64(0x7BA2484C8A0FD54E), U64(0xF3A678CAD9A2E38C), U64(0x39B0BF7DDE437BA2), U64(0xFCAF55C1BF8A4424), U64(0x18FCF680573FA594), U64(0x4C0563B89F495AC3), U64(0x40E087931A00930D), U64(0x8CFFA9412EB642C1), U64(0x68CA39053261169F), U64(0x7A1EE967D27579E2), U64(0x9D1D60E5076F5B6F), U64(0x3810E399B6F65BA2), U64(0x32095B6D4AB5F9B1), U64(0x35CAB62109DD038A), U64(0xA90B24499FCFAFB1), U64(0x77A225A07CC2C6BD), U64(0x513E5E634C70E331), U64(0x4361C0CA3F692F12), U64(0xD941ACA44B20A45B), U64(0x528F7C8602C5807B), U64(0x52AB92BEB9613989), U64(0x9D1DFA2EFC557F73), U64(0x722FF175F572C348), U64(0x1D1260A51107FE97), U64(0x7A249A57EC0C9BA2), U64(0x04208FE9E8F7F2D6), U64(0x5A110C6058B920A0), U64(0x0CD9A497658A5698), U64(0x56FD23C8F9715A4C), U64(0x284C847B9D887AAE), U64(0x04FEABFBBDB619CB), U64(0x742E1E651C60BA83), U64(0x9A9632E65904AD3C), U64(0x881B82A13B51B9E2), U64(0x506E6744CD974924), U64(0xB0183DB56FFC6A79), U64(0x0ED9B915C66ED37E), U64(0x5E11E86D5873D484), U64(0xF678647E3519AC6E), U64(0x1B85D488D0F20CC5), U64(0xDAB9FE6525D89021), U64(0x0D151D86ADB73615), U64(0xA865A54EDCC0F019), U64(0x93C42566AEF98FFB), U64(0x99E7AFEABE000731), U64(0x48CBFF086DDF285A), U64(0x7F9B6AF1EBF78BAF), U64(0x58627E1A149BBA21), U64(0x2CD16E2ABD791E33), U64(0xD363EFF5F0977996), U64(0x0CE2A38C344A6EED), U64(0x1A804AADB9CFA741), U64(0x907F30421D78C5DE), U64(0x501F65EDB3034D07), U64(0x37624AE5A48FA6E9), U64(0x957BAF61700CFF4E), U64(0x3A6C27934E31188A), U64(0xD49503536ABCA345), U64(0x088E049589C432E0), U64(0xF943AEE7FEBF21B8), U64(0x6C3B8E3E336139D3), U64(0x364F6FFA464EE52E), U64(0xD60F6DCEDC314222), U64(0x56963B0DCA418FC0), U64(0x16F50EDF91E513AF), U64(0xEF1955914B609F93), U64(0x565601C0364E3228), U64(0xECB53939887E8175), U64(0xBAC7A9A18531294B), U64(0xB344C470397BBA52), U64(0x65D34954DAF3CEBD), U64(0xB4B81B3FA97511E2), U64(0xB422061193D6F6A7), U64(0x071582401C38434D), U64(0x7A13F18BBEDC4FF5), U64(0xBC4097B116C524D2), U64(0x59B97885E2F2EA28), U64(0x99170A5DC3115544), U64(0x6F423357E7C6A9F9), U64(0x325928EE6E6F8794), U64(0xD0E4366228B03343), U64(0x565C31F7DE89EA27), U64(0x30F5611484119414), U64(0xD873DB391292ED4F), U64(0x7BD94E1D8E17DEBC), U64(0xC7D9F16864A76E94), U64(0x947AE053EE56E63C), U64(0xC8C93882F9475F5F), U64(0x3A9BF55BA91F81CA), U64(0xD9A11FBB3D9808E4), U64(0x0FD22063EDC29FCA), U64(0xB3F256D8ACA0B0B9), U64(0xB03031A8B4516E84), U64(0x35DD37D5871448AF), U64(0xE9F6082B05542E4E), U64(0xEBFAFA33D7254B59), U64(0x9255ABB50D532280), U64(0xB9AB4CE57F2D34F3), U64(0x693501D628297551), U64(0xC62C58F97DD949BF), U64(0xCD454F8F19C5126A), U64(0xBBE83F4ECC2BDECB), U64(0xDC842B7E2819E230), U64(0xBA89142E007503B8), U64(0xA3BC941D0A5061CB), U64(0xE9F6760E32CD8021), U64(0x09C7E552BC76492F), U64(0x852F54934DA55CC9), U64(0x8107FCCF064FCF56), U64(0x098954D51FFF6580), U64(0x23B70EDB1955C4BF), U64(0xC330DE426430F69D), U64(0x4715ED43E8A45C0A), U64(0xA8D7E4DAB780A08D), U64(0x0572B974F03CE0BB), U64(0xB57D2E985E1419C7), U64(0xE8D9ECBE2CF3D73F), U64(0x2FE4B17170E59750), U64(0x11317BA87905E790), U64(0x7FBF21EC8A1F45EC), U64(0x1725CABFCB045B00), U64(0x964E915CD5E2B207), U64(0x3E2B8BCBF016D66D), U64(0xBE7444E39328A0AC), U64(0xF85B2B4FBCDE44B7), U64(0x49353FEA39BA63B1), U64(0x1DD01AAFCD53486A), U64(0x1FCA8A92FD719F85), U64(0xFC7C95D827357AFA), U64(0x18A6A990C8B35EBD), U64(0xCCCB7005C6B9C28D), U64(0x3BDBB92C43B17F26), U64(0xAA70B5B4F89695A2), U64(0xE94C39A54A98307F), U64(0xB7A0B174CFF6F36E), U64(0xD4DBA84729AF48AD), U64(0x2E18BC1AD9704A68), U64(0x2DE0966DAF2F8B1C), U64(0xB9C11D5B1E43A07E), U64(0x64972D68DEE33360), U64(0x94628D38D0C20584), U64(0xDBC0D2B6AB90A559), U64(0xD2733C4335C6A72F), U64(0x7E75D99D94A70F4D), U64(0x6CED1983376FA72B), U64(0x97FCAACBF030BC24), U64(0x7B77497B32503B12), U64(0x8547EDDFB81CCB94), U64(0x79999CDFF70902CB), U64(0xCFFE1939438E9B24), U64(0x829626E3892D95D7), U64(0x92FAE24291F2B3F1), U64(0x63E22C147B9C3403), U64(0xC678B6D860284A1C), U64(0x5873888850659AE7), U64(0x0981DCD296A8736D), U64(0x9F65789A6509A440), U64(0x9FF38FED72E9052F), U64(0xE479EE5B9930578C), U64(0xE7F28ECD2D49EECD), U64(0x56C074A581EA17FE), U64(0x5544F7D774B14AEF), U64(0x7B3F0195FC6F290F), U64(0x12153635B2C0CF57), U64(0x7F5126DBBA5E0CA7), U64(0x7A76956C3EAFB413), U64(0x3D5774A11D31AB39), U64(0x8A1B083821F40CB4), U64(0x7B4A38E32537DF62), U64(0x950113646D1D6E03), U64(0x4DA8979A0041E8A9), U64(0x3BC36E078F7515D7), U64(0x5D0A12F27AD310D1), U64(0x7F9D1A2E1EBE1327), U64(0xDA3A361B1C5157B1), U64(0xDCDD7D20903D0C25), U64(0x36833336D068F707), U64(0xCE68341F79893389), U64(0xAB9090168DD05F34), U64(0x43954B3252DC25E5), U64(0xB438C2B67F98E5E9), U64(0x10DCD78E3851A492), U64(0xDBC27AB5447822BF), U64(0x9B3CDB65F82CA382), U64(0xB67B7896167B4C84), U64(0xBFCED1B0048EAC50), U64(0xA9119B60369FFEBD), U64(0x1FFF7AC80904BF45), U64(0xAC12FB171817EEE7), U64(0xAF08DA9177DDA93D), U64(0x1B0CAB936E65C744), U64(0xB559EB1D04E5E932), U64(0xC37B45B3F8D6F2BA), U64(0xC3A9DC228CAAC9E9), U64(0xF3B8B6675A6507FF), U64(0x9FC477DE4ED681DA), U64(0x67378D8ECCEF96CB), U64(0x6DD856D94D259236), U64(0xA319CE15B0B4DB31), U64(0x073973751F12DD5E), U64(0x8A8E849EB32781A5), U64(0xE1925C71285279F5), U64(0x74C04BF1790C0EFE), U64(0x4DDA48153C94938A), U64(0x9D266D6A1CC0542C), U64(0x7440FB816508C4FE), U64(0x13328503DF48229F), U64(0xD6BF7BAEE43CAC40), U64(0x4838D65F6EF6748F), U64(0x1E152328F3318DEA), U64(0x8F8419A348F296BF), U64(0x72C8834A5957B511), U64(0xD7A023A73260B45C), U64(0x94EBC8ABCFB56DAE), U64(0x9FC10D0F989993E0), U64(0xDE68A2355B93CAE6), U64(0xA44CFE79AE538BBE), U64(0x9D1D84FCCE371425), U64(0x51D2B1AB2DDFB636), U64(0x2FD7E4B9E72CD38C), U64(0x65CA5B96B7552210), U64(0xDD69A0D8AB3B546D), U64(0x604D51B25FBF70E2), U64(0x73AA8A564FB7AC9E), U64(0x1A8C1E992B941148), U64(0xAAC40A2703D9BEA0), U64(0x764DBEAE7FA4F3A6), U64(0x1E99B96E70A9BE8B), U64(0x2C5E9DEB57EF4743), U64(0x3A938FEE32D29981), U64(0x26E6DB8FFDF5ADFE), U64(0x469356C504EC9F9D), U64(0xC8763C5B08D1908C), U64(0x3F6C6AF859D80055), U64(0x7F7CC39420A3A545), U64(0x9BFB227EBDF4C5CE), U64(0x89039D79D6FC5C5C), U64(0x8FE88B57305E2AB6), U64(0xA09E8C8C35AB96DE), U64(0xFA7E393983325753), U64(0xD6B6D0ECC617C699), U64(0xDFEA21EA9E7557E3), U64(0xB67C1FA481680AF8), U64(0xCA1E3785A9E724E5), U64(0x1CFC8BED0D681639), U64(0xD18D8549D140CAEA), U64(0x4ED0FE7E9DC91335), U64(0xE4DBF0634473F5D2), U64(0x1761F93A44D5AEFE), U64(0x53898E4C3910DA55), U64(0x734DE8181F6EC39A), U64(0x2680B122BAA28D97), U64(0x298AF231C85BAFAB), U64(0x7983EED3740847D5), U64(0x66C1A2A1A60CD889), U64(0x9E17E49642A3E4C1), U64(0xEDB454E7BADC0805), U64(0x50B704CAB602C329), U64(0x4CC317FB9CDDD023), U64(0x66B4835D9EAFEA22), U64(0x219B97E26FFC81BD), U64(0x261E4E4C0A333A9D), U64(0x1FE2CCA76517DB90), U64(0xD7504DFA8816EDBB), U64(0xB9571FA04DC089C8), U64(0x1DDC0325259B27DE), U64(0xCF3F4688801EB9AA), U64(0xF4F5D05C10CAB243), U64(0x38B6525C21A42B0E), U64(0x36F60E2BA4FA6800), U64(0xEB3593803173E0CE), U64(0x9C4CD6257C5A3603), U64(0xAF0C317D32ADAA8A), U64(0x258E5A80C7204C4B), U64(0x8B889D624D44885D), U64(0xF4D14597E660F855), U64(0xD4347F66EC8941C3), U64(0xE699ED85B0DFB40D), U64(0x2472F6207C2D0484), U64(0xC2A1E7B5B459AEB5), U64(0xAB4F6451CC1D45EC), U64(0x63767572AE3D6174), U64(0xA59E0BD101731A28), U64(0x116D0016CB948F09), U64(0x2CF9C8CA052F6E9F), U64(0x0B090A7560A968E3), U64(0xABEEDDB2DDE06FF1), U64(0x58EFC10B06A2068D), U64(0xC6E57A78FBD986E0), U64(0x2EAB8CA63CE802D7), U64(0x14A195640116F336), U64(0x7C0828DD624EC390), U64(0xD74BBE77E6116AC7), U64(0x804456AF10F5FB53), U64(0xEBE9EA2ADF4321C7), U64(0x03219A39EE587A30), U64(0x49787FEF17AF9924), U64(0xA1E9300CD8520548), U64(0x5B45E522E4B1B4EF), U64(0xB49C3B3995091A36), U64(0xD4490AD526F14431), U64(0x12A8F216AF9418C2), U64(0x001F837CC7350524), U64(0x1877B51E57A764D5), U64(0xA2853B80F17F58EE), U64(0x993E1DE72D36D310), U64(0xB3598080CE64A656), U64(0x252F59CF0D9F04BB), U64(0xD23C8E176D113600), U64(0x1BDA0492E7E4586E), U64(0x21E0BD5026C619BF), U64(0x3B097ADAF088F94E), U64(0x8D14DEDB30BE846E), U64(0xF95CFFA23AF5F6F4), U64(0x3871700761B3F743), U64(0xCA672B91E9E4FA16), U64(0x64C8E531BFF53B55), U64(0x241260ED4AD1E87D), U64(0x106C09B972D2E822), U64(0x7FBA195410E5CA30), U64(0x7884D9BC6CB569D8), U64(0x0647DFEDCD894A29), U64(0x63573FF03E224774), U64(0x4FC8E9560F91B123), U64(0x1DB956E450275779), U64(0xB8D91274B9E9D4FB), U64(0xA2EBEE47E2FBFCE1), U64(0xD9F1F30CCD97FB09), U64(0xEFED53D75FD64E6B), U64(0x2E6D02C36017F67F), U64(0xA9AA4D20DB084E9B), U64(0xB64BE8D8B25396C1), U64(0x70CB6AF7C2D5BCF0), U64(0x98F076A4F7A2322E), U64(0xBF84470805E69B5F), U64(0x94C3251F06F90CF3), U64(0x3E003E616A6591E9), U64(0xB925A6CD0421AFF3), U64(0x61BDD1307C66E300), U64(0xBF8D5108E27E0D48), U64(0x240AB57A8B888B20), U64(0xFC87614BAF287E07), U64(0xEF02CDD06FFDB432), U64(0xA1082C0466DF6C0A), U64(0x8215E577001332C8), U64(0xD39BB9C3A48DB6CF), U64(0x2738259634305C14), U64(0x61CF4F94C97DF93D), U64(0x1B6BACA2AE4E125B), U64(0x758F450C88572E0B), U64(0x959F587D507A8359), U64(0xB063E962E045F54D), U64(0x60E8ED72C0DFF5D1), U64(0x7B64978555326F9F), U64(0xFD080D236DA814BA), U64(0x8C90FD9B083F4558), U64(0x106F72FE81E2C590), U64(0x7976033A39F7D952), U64(0xA4EC0132764CA04B), U64(0x733EA705FAE4FA77), U64(0xB4D8F77BC3E56167), U64(0x9E21F4F903B33FD9), U64(0x9D765E419FB69F6D), U64(0xD30C088BA61EA5EF), U64(0x5D94337FBFAF7F5B), U64(0x1A4E4822EB4D7A59), U64(0x6FFE73E81B637FB3), U64(0xDDF957BC36D8B9CA), U64(0x64D0E29EEA8838B3), U64(0x08DD9BDFD96B9F63), U64(0x087E79E5A57D1D13), U64(0xE328E230E3E2B3FB), U64(0x1C2559E30F0946BE), U64(0x720BF5F26F4D2EAA), U64(0xB0774D261CC609DB), U64(0x443F64EC5A371195), U64(0x4112CF68649A260E), U64(0xD813F2FAB7F5C5CA), U64(0x660D3257380841EE), U64(0x59AC2C7873F910A3), U64(0xE846963877671A17), U64(0x93B633ABFA3469F8), U64(0xC0C0F5A60EF4CDCF), U64(0xCAF21ECD4377B28C), U64(0x57277707199B8175), U64(0x506C11B9D90E8B1D), U64(0xD83CC2687A19255F), U64(0x4A29C6465A314CD1), U64(0xED2DF21216235097), U64(0xB5635C95FF7296E2), U64(0x22AF003AB672E811), U64(0x52E762596BF68235), U64(0x9AEBA33AC6ECC6B0), U64(0x944F6DE09134DFB6), U64(0x6C47BEC883A7DE39), U64(0x6AD047C430A12104), U64(0xA5B1CFDBA0AB4067), U64(0x7C45D833AFF07862), U64(0x5092EF950A16DA0B), U64(0x9338E69C052B8E7B), U64(0x455A4B4CFE30E3F5), U64(0x6B02E63195AD0CF8), U64(0x6B17B224BAD6BF27), U64(0xD1E0CCD25BB9C169), U64(0xDE0C89A556B9AE70), U64(0x50065E535A213CF6), U64(0x9C1169FA2777B874), U64(0x78EDEFD694AF1EED), U64(0x6DC93D9526A50E68), U64(0xEE97F453F06791ED), U64(0x32AB0EDB696703D3), U64(0x3A6853C7E70757A7), U64(0x31865CED6120F37D), U64(0x67FEF95D92607890), U64(0x1F2B1D1F15F6DC9C), U64(0xB69E38A8965C6B65), U64(0xAA9119FF184CCCF4), U64(0xF43C732873F24C13), U64(0xFB4A3D794A9A80D2), U64(0x3550C2321FD6109C), U64(0x371F77E76BB8417E), U64(0x6BFA9AAE5EC05779), U64(0xCD04F3FF001A4778), U64(0xE3273522064480CA), U64(0x9F91508BFFCFC14A), U64(0x049A7F41061A9E60), U64(0xFCB6BE43A9F2FE9B), U64(0x08DE8A1C7797DA9B), U64(0x8F9887E6078735A1), U64(0xB5B4071DBFC73A66), U64(0x230E343DFBA08D33), U64(0x43ED7F5A0FAE657D), U64(0x3A88A0FBBCB05C63), U64(0x21874B8B4D2DBC4F), U64(0x1BDEA12E35F6A8C9), U64(0x53C065C6C8E63528), U64(0xE34A1D250E7A8D6B), U64(0xD6B04D3B7651DD7E), U64(0x5E90277E7CB39E2D), U64(0x2C046F22062DC67D), U64(0xB10BB459132D0A26), U64(0x3FA9DDFB67E2F199), U64(0x0E09B88E1914F7AF), U64(0x10E8B35AF3EEAB37), U64(0x9EEDECA8E272B933), U64(0xD4C718BC4AE8AE5F), U64(0x81536D601170FC20), U64(0x91B534F885818A06), U64(0xEC8177F83F900978), U64(0x190E714FADA5156E), U64(0xB592BF39B0364963), U64(0x89C350C893AE7DC1), U64(0xAC042E70F8B383F2), U64(0xB49B52E587A1EE60), U64(0xFB152FE3FF26DA89), U64(0x3E666E6F69AE2C15), U64(0x3B544EBE544C19F9), U64(0xE805A1E290CF2456), U64(0x24B33C9D7ED25117), U64(0xE74733427B72F0C1), U64(0x0A804D18B7097475), U64(0x57E3306D881EDB4F), U64(0x4AE7D6A36EB5DBCB), U64(0x2D8D5432157064C8), U64(0xD1E649DE1E7F268B), U64(0x8A328A1CEDFE552C), U64(0x07A3AEC79624C7DA), U64(0x84547DDC3E203C94), U64(0x990A98FD5071D263), U64(0x1A4FF12616EEFC89), U64(0xF6F7FD1431714200), U64(0x30C05B1BA332F41C), U64(0x8D2636B81555A786), U64(0x46C9FEB55D120902), U64(0xCCEC0A73B49C9921), U64(0x4E9D2827355FC492), U64(0x19EBB029435DCB0F), U64(0x4659D2B743848A2C), U64(0x963EF2C96B33BE31), U64(0x74F85198B05A2E7D), U64(0x5A0F544DD2B1FB18), U64(0x03727073C2E134B1), U64(0xC7F6AA2DE59AEA61), U64(0x352787BAA0D7C22F), U64(0x9853EAB63B5E0B35), U64(0xABBDCDD7ED5C0860), U64(0xCF05DAF5AC8D77B0), U64(0x49CAD48CEBF4A71E), U64(0x7A4C10EC2158C4A6), U64(0xD9E92AA246BF719E), U64(0x13AE978D09FE5557), U64(0x730499AF921549FF), U64(0x4E4B705B92903BA4), U64(0xFF577222C14F0A3A), U64(0x55B6344CF97AAFAE), U64(0xB862225B055B6960), U64(0xCAC09AFBDDD2CDB4), U64(0xDAF8E9829FE96B5F), U64(0xB5FDFC5D3132C498), U64(0x310CB380DB6F7503), U64(0xE87FBB46217A360E), U64(0x2102AE466EBB1148), U64(0xF8549E1A3AA5E00D), U64(0x07A69AFDCC42261A), U64(0xC4C118BFE78FEAAE), U64(0xF9F4892ED96BD438), U64(0x1AF3DBE25D8F45DA), U64(0xF5B4B0B0D2DEEEB4), U64(0x962ACEEFA82E1C84), U64(0x046E3ECAAF453CE9), U64(0xF05D129681949A4C), U64(0x964781CE734B3C84), U64(0x9C2ED44081CE5FBD), U64(0x522E23F3925E319E), U64(0x177E00F9FC32F791), U64(0x2BC60A63A6F3B3F2), U64(0x222BBFAE61725606), U64(0x486289DDCC3D6780), U64(0x7DC7785B8EFDFC80), U64(0x8AF38731C02BA980), U64(0x1FAB64EA29A2DDF7), U64(0xE4D9429322CD065A), U64(0x9DA058C67844F20C), U64(0x24C0E332B70019B0), U64(0x233003B5A6CFE6AD), U64(0xD586BD01C5C217F6), U64(0x5E5637885F29BC2B), U64(0x7EBA726D8C94094B), U64(0x0A56A5F0BFE39272), U64(0xD79476A84EE20D06), U64(0x9E4C1269BAA4BF37), U64(0x17EFEE45B0DEE640), U64(0x1D95B0A5FCF90BC6), U64(0x93CBE0B699C2585D), U64(0x65FA4F227A2B6D79), U64(0xD5F9E858292504D5), U64(0xC2B5A03F71471A6F), U64(0x59300222B4561E00), U64(0xCE2F8642CA0712DC), U64(0x7CA9723FBB2E8988), U64(0x2785338347F2BA08), U64(0xC61BB3A141E50E8C), U64(0x150F361DAB9DEC26), U64(0x9F6A419D382595F4), U64(0x64A53DC924FE7AC9), U64(0x142DE49FFF7A7C3D), U64(0x0C335248857FA9E7), U64(0x0A9C32D5EAE45305), U64(0xE6C42178C4BBB92E), U64(0x71F1CE2490D20B07), U64(0xF1BCC3D275AFE51A), U64(0xE728E8C83C334074), U64(0x96FBF83A12884624), U64(0x81A1549FD6573DA5), U64(0x5FA7867CAF35E149), U64(0x56986E2EF3ED091B), U64(0x917F1DD5F8886C61), U64(0xD20D8C88C8FFE65F), U64(0x31D71DCE64B2C310), U64(0xF165B587DF898190), U64(0xA57E6339DD2CF3A0), U64(0x1EF6E6DBB1961EC9), U64(0x70CC73D90BC26E24), U64(0xE21A6B35DF0C3AD7), U64(0x003A93D8B2806962), U64(0x1C99DED33CB890A1), U64(0xCF3145DE0ADD4289), U64(0xD0E4427A5514FB72), U64(0x77C621CC9FB3A483), U64(0x67A34DAC4356550B), U64(0xF8D626AAAF278509), };The array Random64 is in fact a concatenation of four subarrays

RandomPiece (offset: 0, length: 768) RandomCastle (offset: 768, length: 4) RandomEnPassant (offset: 772, length: 8) RandomTurn (offset: 780, length: 1)"key" is a so-called "Zobrist hash function". In other words it is the

key=piece^castle^enpassant^turn;

offset_piece=64*kind_of_piece+8*row+file;"row" and "file" are counted from 0 to 7. With this convention one has

square file row ====================== a1 0 0 h1 7 0 a8 0 7 h8 7 7"kind_of_piece" is encoded as follows

black pawn 0 white pawn 1 black knight 2 white knight 3 black bishop 4 white bishop 5 black rook 6 white rook 7 black queen 8 white queen 9 black king 10 white king 11

white can castle short 0 white can castle long 1 black can castle short 2 black can castle long 3If none of these flags apply then castle=0.

Note that these flags represent "potential future castling" as in the FEN standard even if such castling is currently not possible due to blocking pieces or enemy attacks.

In other words these flags are all true in the starting position and are only updated after the appropriate king, rook or castling moves.

Note that this is **different from the FEN standard**. In the FEN standard
the presence of an "en passant target square" after a double pawn push
is unconditional.

Also note that it is irrelevant if the potential en passant capturing move is legal or not (examples where it would not be legal are when the capturing pawn is pinned or when the double pawn push was a discovered check).

starting position FEN=rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 key=463b96181691fc9c position after e2e4 FEN=rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1 key=823c9b50fd114196 position after e2e4 d75 FEN=rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 2 key=0756b94461c50fb0 position after e2e4 d7d5 e4e5 FEN=rnbqkbnr/ppp1pppp/8/3pP3/8/8/PPPP1PPP/RNBQKBNR b KQkq - 0 2 key=662fafb965db29d4 position after e2e4 d7d5 e4e5 f7f5 FEN=rnbqkbnr/ppp1p1pp/8/3pPp2/8/8/PPPP1PPP/RNBQKBNR w KQkq f6 0 3 key=22a48b5a8e47ff78 position after e2e4 d7d5 e4e5 f7f5 e1e2 FEN=rnbqkbnr/ppp1p1pp/8/3pPp2/8/8/PPPPKPPP/RNBQ1BNR b kq - 0 3 key=652a607ca3f242c1 position after e2e4 d7d5 e4e5 f7f5 e1e2 e8f7 FEN=rnbq1bnr/ppp1pkpp/8/3pPp2/8/8/PPPPKPPP/RNBQ1BNR w - - 0 4 key=00fdd303c946bdd9 position after a2a4 b7b5 h2h4 b5b4 c2c4 FEN=rnbqkbnr/p1pppppp/8/8/PpP4P/8/1P1PPPP1/RNBQKBNR b KQkq c3 0 3 key=3c8123ea7b067637 position after a2a4 b7b5 h2h4 b5b4 c2c4 b4c3 a1a3 FEN=rnbqkbnr/p1pppppp/8/8/P6P/R1p5/1P1PPPP1/1NBQKBNR b Kkq - 0 4 key=5c3f9b829b279560

bits meaning =================================== 0,1,2 to file 3,4,5 to row 6,7,8 from file 9,10,11 from row 12,13,14 promotion piece"promotion piece" is encoded as follows

none 0 knight 1 bishop 2 rook 3 queen 4If the move is "0" (a1a1) then it should simply be ignored. It seems to me that in that case one might as well delete the entry from the book.

white short e1h1 white long e1a1 black short e8h8 black long e8a8It is technically possible that these moves are legal non-castling moves. So before deciding that these are really castling moves the implementation may for example verify that there is really a king present on e1/e8.

The Polyglot book generator sets it to 2*(wins)+(draws), globally scaled to fit into 16 bits. A move with a weight of zero is deleted from the book. This is just a convention and book authors are free to set this field according to their taste.

If random play is enabled in Polyglot then the probability that a move is selected is its weight divided by the sum of the weights of all the moves in the given position. In XBoard, which also supports Polyglot books, the weight can be raised to a power N (0 <= N <= infinity) before doing the probability calculation, enhancing or completely destroying the effect of the weights.

- pg_key.c: This little utility computes the PG key of a FEN. Note that it does ZERO error checking on the legality of the FEN and hence will segfault if something is wrong.
- pg_show.c: This utility looks up a PG key in a PG book and prints out the moves and their (relative) weights.

The Zobrist hash function used in Polyglot does not keep track of which rook has castling rights if there are multiple rooks present on the same side of the king. However it is rather unlikely that this situation would occur in the opening. So the ambiguity can be resolved in a satisfactory way by making the following convention.

** Positions in which a rook has castling rights which is not an outer
rook (closest to a or h file) should not be included in the book. **

Nonetheless this is an unsatisfactory situation. Therefore the
upcoming versions of xboard/winboard extend the Polyglot hash function
in such a way that it takes into account the full castling rights in
Chess960, therefore
**removing the need of the above disambiguating convention**. This is done in a backward compatible way. I.e. ordinary
chess positions or Chess960 positions in which there is no castling
ambiguity will keep their old hash key.

The above declaration of RandomCastle is replaced by

const uint64 RandomCastle[16]={ < to be filled in > }In this case "castle" will be the exclusive or of entries taken from RandomCastle, one for each rook that has castling rights (so at most four offsets). The offset for a rook that has castling rights is computed as follows.

- If the rook is an outer rook (i.e. closest to the a or h file) then
the offset is
0 if the rook is white and on the king side 1 if the rook is white and on the queen side 2 if the rook is black and on the king side 3 if the rook is black and on the queen side

(this is like in ordinary chess) - If the rook is not an outer rook then the offset is
3+file if the rook is white 9+file if the rook is black

where "file" denotes the file the rook is on, encoded in the usual way, i.e. b=1,c=2,d=3,e=4,f=5,g=6.

To map a (piece, square) combination to a hash key, however, only the square number modulo 64 and the piece number modulo 12 is used as index in the key table. The square number divided by 64 and piece number divided by 12 is then used to decide how the retreived key should be (bit-wise) rotated to get the actual key. Square numbers in the range 64-127 rotate the key left by 8 bits, while piece values in the ranges 12-23, 24-35 and 36-47 rotate left by an additional 16, 32 or 48 bits, respectively. This is sufficient to handle boards of upto 128 squares, and up to 24 piece types.

A number derived from the variant can be XORed to the overall key, to prevent positions from variants with equal board and piece types (e.g. suicide, losers or atomic) to map to the same key, and invalidates books made for one of those for accidental use by any of the others. The table below defines the number that should be used for some common variants. Note that some variants that are mutually compatible use the same number, so that they can use the same opening book.

0 standard Chess (aka Mad Queen), WildCastle, NoCastle, Fischer Random Chess (aka Chess960), 0 Xiangqi (Chinese Chess), 6 Crazyhouse, 7 Losers Chess, 8 Suicide Chess, Giveaway Chess, 10 TwoKings, 12 Atomic Chess, 13 3Check, 14 Shatranj, 23 Shogi (Japanese Chess), 25 Courier Chess, 26 Gothic Chess, Capablanca Chess, Capablanca Random Chess, 28 Knightmate, 30 Cylinder Chess, 31 Falcon Chess, 33 Berolina Chess, 34 Janus Chess, 35 Superchess, 36 Great Shatranj, 38 Makruk (Thai Chess), 39 S-Chess (aka Seirawan Chess), 40 Grand Chess, 41 Spartan Chess,

For variants with holdings from which pieces can be brought (back) in play (e.g. Crazyhouse, Shogi, S-Chess), the holdings are also part of the game state, and must be encoded in the key. To do this, the holdings are considered as a single off-board square with the next available number (so square number 64 in Crazyhouse). The (piece type, square number) pair is than mapped onto a key in the same way as for on-board pieces. A complication here is that multiple pieces, possibly of the same type, can be on this 'holdings square', so that XORing the corresponding key into the total will not work. (Having two pieces of a certain type would then be indistinguishable from having none, as A XOR A equals 0 for any A!) Therefore the holdings keys are not XORed but added to the total key, after all other key terms have been taken into account through XOR.

The move encoding on large boards is fromSquare*boardSize + toSquare + boardSize*boardSize*promotionType. For large boards this might leave a shortage of promotion types, but fortunately promotions are not very common in opening theory. The meaning of the promotionType code can be variant-dependent. Especially if there is a shortage of codes, the most common promotions should receive the lowest codes. (E.g. in Grand Chess the board is 10x10, so the promotion-type multiplier is 10,000, while the 16-bit move encoding only runs upto 65,535. So there is only room for 6 promotion types, while 7 would be needed for the 6 possible piece types and non-promotion.) In asymmetric variants (e.g. Spartan Chess) the same code need not indicate the same piece type for both sides.