Author: Michel Langeveld
Date: 07:40:34 06/06/99
I have found a position which the nodecount does not match sigma nodecount of all succesors. Nodecount main position: 398 nodes Sigma of all successors : 399 nodes (1x20+2x19+18x18+1x17) Conclusion: one node is lost in the mainposition using perft. I have included 2 scripts to examine the problem yourself. --- script 1: to calculate the main position total is (398 nodes) --- log off ponder=off setboard rnbqkbnr/2pppppp/p7/Pp6/8/8/1PPPPPPP/RNBQKBNR/ w b6 perft 2 exit --- end script 1 --- --- script 2: to calculate all successor nodes (total is 399)--- log off ponder=off setboard rnbqkbnr/2pppppp/p7/Pp6/8/8/RPPPPPPP/1NBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/R7/1PPPPPPP/1NBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/R7/8/1PPPPPPP/1NBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/2N5/1PPPPPPP/R1BQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/N7/1PPPPPPP/R1BQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/7N/1PPPPPPP/RNBQKB1R/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/5N2/1PPPPPPP/RNBQKB1R/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/1P6/8/2PPPPPP/RNBQKBNR/ b b3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/1P6/2PPPPPP/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/2P5/8/1P1PPPPP/RNBQKBNR/ b c3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/2P5/1P1PPPPP/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/3P4/8/1PP1PPPP/RNBQKBNR/ b d3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/3P4/1PP1PPPP/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/4P3/8/1PPP1PPP/RNBQKBNR/ b e3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/4P3/1PPP1PPP/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/5P2/8/1PPPP1PP/RNBQKBNR/ b f3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/5P2/1PPPP1PP/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/6P1/8/1PPPPP1P/RNBQKBNR/ b g3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/6P1/1PPPPP1P/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/7P/8/1PPPPPP1/RNBQKBNR/ b h3 perft 1 setboard rnbqkbnr/2pppppp/p7/Pp6/8/7P/1PPPPPP1/RNBQKBNR/ b perft 1 setboard rnbqkbnr/2pppppp/pP6/1p6/8/8/1PPPPPPP/RNBQKBNR/ b perft 1 exit --- end of script 2 ---
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