Author: E. Nielsen
Date: 03:02:21 12/17/04
Go up one level in this thread
Just the hint I needed... :) On December 14, 2004 at 16:30:42, Peter Fendrich wrote: >On December 14, 2004 at 14:55:41, E. Nielsen wrote: > >>Hi, >> >>We have got this little strange 'challenge' with our move-generator... ;-) >> >>There is this one perft-test from >>http://homepages.caverock.net.nz/~peter/perft.htm >>that fails from depth 3. >> >>r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - >> >>We get: >>perft 1 >>Total moves=48 [ok] >>perft 2 >>Total moves=2039 [ok] >>perft 3 >>Total moves=97898 [should be 97862 i.e 36 positions less] >>perft 4 >>Total moves=4087387 [should be 4085603 i.e 1784 positions less] >> >> >>Is there anybody who has any idea on where such an error could originate? >> >> >>Thanks in advance >>Eyðun Nielsen > >One good method here that I lerarned from the program "Sharper" is to write >another function (I call it perftm). >It does exactly what perft does but for each move in the position. >You will get something like: > >------------------------------ >>r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - >perftm 3 (48 moves) = >0 Be2xa6 : 1907 >1 Qf3xf6 : 2111 >2 g2xh3 : 1970 >3 d5xe6 : 2241 >4 Ne5xg6 : 1997 >5 Ne5xd7 : 2124 >6 Ne5xf7 : 2080 >7 Qf3xh3 : 2360 >8 d5d6 : 1991 >9 Bd2e3 : 2136 >10 Bd2f4 : 2000 >11 Be2d3 : 2050 >12 Be2c4 : 2082 >13 Ne5c6 : 2027 >14 Ne5d3 : 1803 >15 Ne5c4 : 1880 >16 Bd2g5 : 2134 >17 Be2b5 : 2057 >18 Nc3b5 : 2138 >19 Ne5g4 : 1878 >20 Bd2c1 : 1963 >21 Bd2h6 : 2019 >22 Be2d1 : 1733 >23 Be2f1 : 2060 >24 Ke1g1 : 2059 >25 Ke1c1 : 1887 >26 Nc3a4 : 2203 >27 g2g4 : 1843 >28 g2g3 : 1882 >29 b2b3 : 1964 >30 a2a3 : 2186 >31 a2a4 : 2149 >32 Nc3d1 : 2040 >33 Ra1d1 : 1885 >34 Qf3d3 : 2005 >35 Qf3e3 : 2174 >36 Rh1g1 : 2013 >37 Ra1b1 : 1969 >38 Ra1c1 : 1968 >39 Rh1f1 : 1929 >40 Qf3g3 : 2214 >41 Qf3f4 : 2132 >42 Qf3g4 : 2169 >43 Qf3f5 : 2396 >44 Qf3h5 : 2267 >45 Nc3b1 : 2038 >46 Ke1d1 : 1894 >47 Ke1f1 : 1855 >Total: 97862 >---------------------------- >Now compare the each moves figures with the right ones and select a move that >differs. >Make the move and do "perftm 2", compare again and so on. When you've reached >"perftm 1" you see exactly what move is missing. > >You need a prgram to compare your numbers with. Download Sharper from >http://www.albert.nu/programs/sharper/main.htm >My "perftm 3" is called "divide 3" in Sharper. > >/Peter
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