Compare your engine's performance: Corrections +++

[amanjpro]

Something's going wrong for me ...

Code: Select all

setoption name Hash value 512
position fen 5k2/ppp2r1p/2p2ppP/8/2Q5/2P1bN2/PP4P1/1K1R4 w - - 0 1
go
info depth  1 time      0 nodes       122 nps  122000 hashfull     1 score cp  815 pv d1d8 f8e7 
info depth  2 time      0 nodes       404 nps  404000 hashfull     6 score cp  832 pv c4b4 f7e7 b4b7 
info depth  3 time      1 nodes       606 nps  303000 hashfull     8 score cp  859 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7c8 
info depth  4 time      2 nodes      1156 nps  385000 hashfull    14 score cp  854 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7h7 
info depth  5 time      5 nodes      3274 nps  545000 hashfull    22 score cp  892 pv d1d8 f8e7 d8c8 e3b6 c4e4 e7d6 b1c2 
info depth  6 time     10 nodes      4784 nps  434000 hashfull    47 score cp 1146 pv d1d8 f8e7 d8c8 e3f4 c4f4 e7d7 c8c7 d7e6 
info depth  7 time      8 nodes      4458 nps  495000 hashfull    60 score cp 1182 pv d1d8 f8e7 d8c8 e3f4 c4f4 e7e6 f4e4 e6d6 b1c2 
info depth  8 time     56 nodes     31244 nps  548000 hashfull   118 score cp 1260 pv d1d8 f8e7 d8c8 f7f8 c4b4 c6c5 b4e4 e7d7 e4d4 c5d4 c8d8 f8d8 c3d4 
info depth  9 time      9 nodes     15714 nps 1571000 hashfull   133 score cp 1284 pv d1d8 f8e7 d8c8 f7f8 c4b4 c6c5 b4e4 e7d7 c8f8 e3h6 e4d5 d7e7 f8f7 e7e8 
info depth 10 time     47 nodes     64839 nps 1350000 hashfull   195 score cp 1411 pv d1d8 f8e7 d8c8 e3b6 c4e2 e7d7 e2e8 d7d6 c8d8 d6c5 e8f7 c5b5 f7h7 g6g5 
info depth 11 time     59 nodes     87686 nps 1461000 hashfull   213 score cp 1479 pv d1d8 f8e7 d8c8 f7f8 c4b4 e7d7 b4f8 e3h6 c8d8 d7e6 d8e8 e6d5 f8f7 d5c5 f7f6 
info depth 12 time    767 nodes   1029884 nps 1340000 hashfull   865 score cp 1699 pv d1d8 f8e7 d8c8 e7d6 c4f7 e3f2 f7c7 d6e6 c7h7 a7a6 h7b7 e6f5 b7a6 c6c5 
info depth 13 time    880 nodes   1330233 nps 1509000 hashfull  1498 score cp 1805 pv d1d8 f8e7 d8c8 e3g5 c8c7 e7d6 c7f7 f6f5 f3g5 b7b6 g5h7 b6b5 c4d3 d6e6 
info depth 14 time   1076 nodes   1642165 nps 1524000 hashfull  1715 score cp 1846 pv d1d8 f8e7 d8c8 e7d6 c4f7 d6c5 f7e7 c5b6 e7e3 c6c5 e3e6 c7c6 e6b3 b6a6 c8c7 a6a5 c7b7 a5a6 b7h7 
info depth 15 time   4011 nodes   5517705 nps 1375000 hashfull  2895 score cp 2232 pv d1d8 f8e7 d8c8 e7d6 c4f7 e3f2 f7c7 d6e6 c7h7 f2g1 c8e8 e6d5 h7f7 d5c5 h6h7 c5b5 h7h8q b5b6 
info depth 16 time   5586 nodes   7162541 nps 1282000 hashfull  3488 score mate 11 pv d1d8 f8e7 d8c8 a7a6 c4e4 e7d7 c8e8 d7d6 e4e6 d6c5 e6e3 c5b5 f3d4 b5c5 d4b3 c5d5 e3e4 d5d6 e4d4 
info depth 17 time   4034 nodes   5254956 nps 1302000 hashfull  3735 score mate 11 pv d1d8 f8e7 d8c8 e7d6 c4f7 d6c5 f7e7 c5b6 e7b4 b6a6 c8c7 c6c5 b4b7 a6a5 b2b4 c5b4 c3b4 a5a4 b7a6 a4b4 c7c4 
info depth 18 time  48912 nodes  64910243 nps 1327000 hashfull  3743 score mate 11 pv d1d8 f8e7 d8c8 e7d6 c4f7 d6c5 f7e7 c5c4 b2b3 c4d3 
info depth 19 time 164223 nodes 231864097 nps 1411000 hashfull  6091 score mate 11 pv d1d8 f8e7 d8c8 e7d6 c4f7 d6c5 f7e7 c5c4 b2b3 c4b5 e7b4 b5a6 c8c7 
info depth 20 time 942192 nodes 1395990614 nps 1481000 hashfull 10183 score mate 12 pv d1d8 f8e7 d8c8 a7a5 c4e4 e7d7 e4e8 d7d6 c8d8 f7d7 d8d7 d6c5 e8e3 c5b5 e3a7 b7b6 f3d4 b5c4 a7a6 b6b5 b1c2

I believe you should leave it for long enough to find a shorter mate, here is for Zahak (dev version):
CPU: 2.90GHz
Hash: 512
Engine, Zahak written in GoLang
Time: 21 seconds (found mate earlier, but shorter mate needed one more iteration)

Code: Select all

setoption name Hash value 512
position fen 5k2/ppp2r1p/2p2ppP/8/2Q5/2P1bN2/PP4P1/1K1R4 w - - 0 0
go infinite
info depth 1 seldepth 2 hashfull 0 nodes 138 nps 845204 score cp 1035 time 0 pv d1d8 f8e7
info depth 2 seldepth 4 hashfull 0 nodes 1219 nps 1252895 score cp 1005 time 0 pv c4b4 f7e7 d1d8 f8f7
info depth 3 seldepth 6 hashfull 0 nodes 7068 nps 1721648 score cp 1042 time 4 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6
info depth 4 seldepth 7 hashfull 0 nodes 7289 nps 1700694 score cp 1042 time 4 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7h7
info depth 5 seldepth 8 hashfull 0 nodes 8362 nps 1608617 score cp 1160 time 5 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7h7 a7a5
info depth 6 seldepth 11 hashfull 0 nodes 9755 nps 1582534 score cp 1163 time 6 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6d7 f6g7 d7c8 g7h7
info depth 7 seldepth 14 hashfull 0 nodes 11310 nps 1555667 score cp 1278 time 7 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6d7 f6g7 d7d8 g7h8 d8d7 h8h7 d7e6
info depth 8 seldepth 13 hashfull 0 nodes 16283 nps 1489128 score cp 1427 time 10 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d8 f7f6 d8e8 f6e5 e8d7 e5e3 b7b6 e3e5
info depth 9 seldepth 20 hashfull 0 nodes 29983 nps 1379650 score cp 1438 time 21 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 f3e5 b6a5 e5c4 a5b5 c4d6 b5b6
info depth 10 seldepth 17 hashfull 0 nodes 37703 nps 1363554 score cp 1449 time 27 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 f3e5 b6a5 e6d7
info depth 11 seldepth 19 hashfull 0 nodes 58301 nps 1395203 score cp 1482 time 41 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d8 f7f6 d8e8 f6e5 e8d7 e5e3 a7a5 e3d4 d7e7 d4e5 e7d7 e5g7 d7d6 g7h7
info depth 12 seldepth 20 hashfull 0 nodes 113105 nps 1428347 score cp 1497 time 79 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5c4 e5e3 a7a5 e3f4 c4d5 f4d4 d5e6 f3g5 e6f5 g5h7 b7b5
info depth 13 seldepth 19 hashfull 0 nodes 188928 nps 1441597 score cp 1566 time 131 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 b6a6 f3g5 b7b5 g5h7 a6b7 e3e5 b7b6 h7g5
info depth 14 seldepth 22 hashfull 0 nodes 243191 nps 1441584 score cp 1573 time 168 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 b6a6 f3g5 b7b5 g5h7 a6b7 e3e5 b7b6 e5d4 c6c5 d4f6 c7c6
info depth 15 seldepth 26 hashfull 1 nodes 405169 nps 1439162 score cp 1638 time 281 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 b6a6 f3g5 b7b6 g5h7 a6a5 e3e5 c6c5 e5c7 a5b5 c7d7 b5c4 d7f7 c4d3 f7g6 d3d2
info depth 16 seldepth 26 hashfull 2 nodes 661441 nps 1440422 score cp 1676 time 459 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 b6a6 f3g5 b7b6 g5h7 c6c5 e3d3 a6b7 d3g6 b6b5 g6e6 c7c6 e6d7 b7b6 h7g5 b5b4
info depth 17 seldepth 24 hashfull 4 nodes 997349 nps 1476913 score cp 1740 time 675 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a5 d7h7 g6g5 f3g5 a5a4 h7d7 a4a3 b2a3 c5c4
info depth 18 seldepth 29 hashfull 7 nodes 1692535 nps 1499194 score cp 1791 time 1128 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 c5c4 d7h7 g6g5 f3g5 a7a6 h7f7 b6c5 f7e7 c5d5 e7e6 d5c5 e6e5 c5b6 h6h7
info depth 19 seldepth 27 hashfull 11 nodes 2421094 nps 1531407 score cp 1827 time 1580 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 b6a5 e6d7 b7b6 d7c7 a5a6 c7h7 g6g5 f3g5 c5c4 h7g6 a6b5 g6f5 b5c6 h6h7
info depth 20 seldepth 29 hashfull 25 nodes 5018110 nps 1628426 score cp 2083 time 3081 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 b6a6 d7h7 g6g5 h7g6 a6b5 f3d4 c5d4 g6g5 b5c4 h6h7 d4c3 h7h8q c3b2 b1b2
info depth 21 seldepth 34 hashfull 30 nodes 6066332 nps 1650223 score cp 2374 time 3676 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 b6a6 d7h7 g6g5 h7g6 b7b6 g6g5 b6b5 g5g6 a6a5 b2b4 c5b4 c3b4 a5a4 h6h7 c6c5 g6c2 a4b4 c2b3 b4a5
info depth 22 seldepth 34 hashfull 42 nodes 8739593 nps 1679223 score cp 2437 time 5204 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 g6g5 f3g5 b6a6 d7h7 a6b6 h7f7 a7a5 f7b3 b6a6 h6h7 b7b5 h7h8q c5c4 h8c8 a6b6 c8d8 b6a6 d8a8 a6b6
info depth 23 seldepth 35 hashfull 64 nodes 13956527 nps 1724679 score cp 2554 time 8092 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 g6g5 f3g5 c5c4 d7h7 a7a6 h7g6 b6a5 g6f5 a5b6 f5f7 c6c5 f7e6 b6b5 a2a4 b5a5 h6h7 b7b6 h7h8q a5a4 e6b6
info depth 24 seldepth 32 hashfull 96 nodes 21769422 nps 1749898 score cp 2628 time 12440 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a6 d7h7 b6a7 h7f7 a6a5 f7g6 a5a4 h6h7 a4a3 h7h8q a3b2 g6f7 c5c4 b1b2 a7b6 f7c4 b6c7
info depth 25 seldepth 45 hashfull 136 nodes 33560949 nps 1773346 score mate +22 time 18925 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a6 d7h7 b6b5 h7b7 b5c4 b7f7 c4d3 f7d7 d3e3 d7e6 e3d3 e6g6 d3e3 g6g5 e3f2 h6h7 f2f1 g5c1 f1g2 c1d2 g2g3 d2e1 g3f3 h7h8q c5c4 h8h1 f3f4 h1h4 f4f5 e1e4
info depth 26 seldepth 15 hashfull 147 nodes 38155700 nps 1782321 score mate +7 time 21407 pv c4e6 e3h6 d1d8 f8g7 f3e5 f6e5 e6e5 f7f6 d8d7 g7g8 e5f6 h6f8 f6f7 g8h8 f7f8

Now, trying the same but with 4 CPUs:
Time: 15 seconds
Hash: 1024
Threads: 4

Code: Select all

setoption name Hash value 1024
setoption name Threads value 4
position fen 5k2/ppp2r1p/2p2ppP/8/2Q5/2P1bN2/PP4P1/1K1R4 w - - 0 0
go infinite
info depth 1 seldepth 2 hashfull 0 nodes 138 nps 547975 score cp 1035 time 0 pv d1d8 f8e7
info depth 2 seldepth 4 hashfull 0 nodes 1449 nps 1364442 score cp 1005 time 1 pv c4b4 f7e7 d1d8 f8f7
info depth 4 seldepth 7 hashfull 0 nodes 3387 nps 1409404 score cp 1042 time 2 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7h7
info depth 5 seldepth 10 hashfull 0 nodes 11807 nps 2556465 score cp 1148 time 4 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6d7 f6g7 d7d6
info depth 6 seldepth 11 hashfull 0 nodes 13824 nps 2672980 score cp 1163 time 5 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6d7 f6g7 d7c8 g7h7
info depth 7 seldepth 14 hashfull 0 nodes 16556 nps 2772867 score cp 1278 time 5 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6d7 f6g7 d7c8 g7g8 c8d7 g8h7 d7e6
info depth 8 seldepth 15 hashfull 0 nodes 21678 nps 1828017 score cp 1425 time 11 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6e5
info depth 9 seldepth 17 hashfull 0 nodes 29513 nps 1811572 score cp 1438 time 16 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6b3 b6a6 b3e6
info depth 10 seldepth 17 hashfull 0 nodes 42746 nps 2066364 score cp 1469 time 20 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 b1c2 a7a5 e6e5
info depth 11 seldepth 17 hashfull 0 nodes 52511 nps 1915867 score cp 1469 time 27 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 b6a6 e3d4 b7b6 b1c2 a6b7 d4e5
info depth 12 seldepth 18 hashfull 0 nodes 98429 nps 1541893 score cp 1522 time 63 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5c4 e5e3 a7a5 f3g5 c4b5 e3e5 c6c5 g5h7 b5b6
info depth 13 seldepth 21 hashfull 0 nodes 145934 nps 1716238 score cp 1528 time 85 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5c4 e5e3 a7a5 f3g5 c4b5 e3e5 b5c4 e5d4 c4b5 a2a4 b5a6 g5h7
info depth 14 seldepth 20 hashfull 1 nodes 325594 nps 1203805 score cp 1659 time 270 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 b6a6 e3e7 a6b6 e7h7 g6g5 f3g5 a7a5 h7f7 a5a4
info depth 15 seldepth 22 hashfull 1 nodes 560165 nps 1646212 score cp 1669 time 340 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a6 d7h7 g6g5 f3g5 a6a5 h7d7 a5a4
info depth 16 seldepth 23 hashfull 3 nodes 997613 nps 1674721 score cp 1719 time 595 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a5 d7h7 g6g5 f3g5 a5a4 h7d7 a4a3 b2a3
info depth 17 seldepth 25 hashfull 5 nodes 1654124 nps 2147867 score cp 1774 time 770 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a5 d7h7 g6g5 f3g5 b6a6 h7d3 b7b5 h6h7 c5c4 d3d4
info depth 18 seldepth 25 hashfull 7 nodes 2074572 nps 2051584 score cp 1798 time 1011 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 b6a6 d7h7 g6g5 f3g5 a6b6 h7d3 c5c4 d3c4 b6c7 h6h7
info depth 19 seldepth 29 hashfull 15 nodes 3328903 nps 1831373 score cp 1919 time 1817 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 b6a5 e6d7 g6g5 d7c7 a5a6 f3g5 b7b5 c7c6 a6a5 g5h7 b5b4 c6c5 a5a6 c3b4 a6b7 h7f6
info depth 20 seldepth 34 hashfull 21 nodes 5020771 nps 2097693 score cp 2321 time 2393 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 b6b5 e6d7 b5a6 d7h7 g6g5 h7c7 g5g4 h6h7 g4f3 h7h8q f3g2 c7c5 g2g1q c5g1 b7b6 h8c8 a6a5 g1g5 b6b5 c8c7 a5a6
info depth 21 seldepth 31 hashfull 26 nodes 7303434 nps 2525985 score cp 2387 time 2891 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 b6b5 e6d7 b5b6 d7h7 g6g5 h7g6 c7c6 f3g5 b6c7 g6f7 c7d6 f7b7 d6e5 h6h7 e5f5 h7h8q f5g5 b7a7
info depth 22 seldepth 31 hashfull 44 nodes 10301681 nps 2143436 score cp 2485 time 4806 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 g6g5 f3g5 a7a5 g5h7 a5a4 h7f6 b6a6 d7d3 b7b5 d3f5 b5b4 h6h7 b4c3 h7h8q c3b2 b1b2
info depth 23 seldepth 33 hashfull 68 nodes 14466044 nps 1997509 score cp 2530 time 7242 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 a7a5 d7h7 b6a6 h7g7 b7b6 g7g6 a6b7 g6f7 b7c8 f7f8 c8b7 f8g7 b7a6 h6h7 a6b5 h7h8q a5a4 g7d7
info depth 24 seldepth 43 hashfull 130 nodes 26803387 nps 1866078 score mate +21 time 14363 pv d1d8 f8e7 d8d7 e7d7 c4f7 d7d6 f7f6 d6c5 f6e5 c5b6 e5e3 c6c5 e3e6 c7c6 e6d7 g6g5 f3g5 a7a5 g5h7 b6b5 d7b7 b5c4 b7a6 c4d5 h7f6 d5e5 h6h7 c5c4 a6a5 c6c5 a5c5 e5f4 c5c4 f4g5 c4g4 g5f6 h7h8q f6e7 h8e5 e7d8 e5d6 d8e8 g4d7
info depth 25 seldepth 15 hashfull 139 nodes 46064372 nps 2930214 score mate +7 time 15720 pv c4e6 e3h6 f3e5 f6e5 d1d8 f8g7 e6e5 f7f6 d8d7 g7g8 e5f6 a7a5 d7d8 h6f8 d8f8

[amanjpro]

Ethereal 13.31: info depth 33 seldepth 26 multipv 1 score mate 7 time 3984 nodes 11679947 nps 2930000 tbhits 0 hashfull 972 pv c4e4 e3h6 d1d8 f8g7 f3d4 h6f4 d4e6 g7h6 d8d3 f4g3 d3g3 f7f8 g3h3

Woah, that is fast, what CPU?

[JVMerlino]

As stated in the other thread, The King from CM9000 finds Mate in 7 in less than one second:

Code: Select all

Time	Depth	Score	Positions	Moves
0:00	1/3	13.99	4781		1.Rd8+ Ke7 2.Rd7+ Kxd7 3.Qxf7+
					Kd6 4.Qxf6+ Kc5 5.Qe5+ Kb6 6.Qxe3+
					c5
0:00	1/4	17.01	28884		1.Rd8+ Ke7 2.Qd3 f5 3.Rg8 Bc5 4.Qd8+
					Ke6 5.Ng5+ Ke5 6.Nxf7+ Ke6 7.Ng5+
					Ke5 8.Qxc7+ Kd5 9.Nxh7
0:00	1/5	18.32	95220		1.Rd8+ Ke7 2.Qd3 f5 3.Rg8 Bc5 4.Qd8+
					Ke6 5.Ng5+ Ke5 6.Nxf7+ Ke6 7.Ng5+
					Ke5 8.Re8+ Kf4 9.Ne6+ Kg3 10.Qg5+
					Kh2 11.Nxc5
0:00	1/5	Mate08	112202		1.Qe6 Bxh6 2.Rd8+ Kg7 3.Ne5 fxe5
					4.Qxe5+ Rf6 5.Rd7+ Kg8 6.Qxf6 c5
					7.Qf7+ Kh8 8.Qxh7#
0:00	1/6	Mate08	148296		1.Qe6 Bxh6 2.Rd8+ Kg7 3.Ne5 fxe5
					4.Qxe5+ Rf6 5.Rd7+ Kg8 6.Qxf6 c5
					7.Qf7+ Kh8 8.Qxh7#
0:00	1/7	Mate08	304400		1.Qe6 Bxh6 2.Rd8+ Kg7 3.Ne5 fxe5
					4.Qxe5+ Rf6 5.Rd7+ Kg8 6.Qxf6 c5
					7.Qf7+ Kh8 8.Qxh7#
0:00	1/8	Mate08	692755		1.Qe6 Bxh6 2.Rd8+ Kg7 3.Ne5 fxe5
					4.Qxe5+ Rf6 5.Rd7+ Kg8 6.Qxf6 c5
					7.Qf7+ Kh8 8.Qxh7#
0:00	1/8	Mate07	1278179		1.Qe4 Bd2 2.Rxd2 Re7 3.Rd8+ Kf7
					4.Qc4+ Re6 5.Rd7+ Kf8 6.Qxe6 f5
					7.Qf7#
0:00	2/9	Mate07	1399236		1.Qe4 Bd2 2.Rxd2 Re7 3.Rd8+ Kf7
					4.Qc4+ Re6 5.Rd7+ Kf8 6.Qxe6 f5
					7.Qf7#

[klx]

Related to my recent thread, how do we even know that mate in 7 is optimal? I mean, I believe that it is, but some engines here need 20+ or even 30+ depth to find mate in 7, how'd one know when the shortest mate is found?

[amanjpro]

Related to my recent thread, how do we even know that mate in 7 is optimal? I mean, I believe that it is, but some engines here need 20+ or even 30+ depth to find mate in 7, how'd one know when the shortest mate is found?

It might not be, if you want to be 100% sure about optimal paths for all possible positions, then you need to do alpha-beta without any other pruning/reductions. But that is going to be super slow

[JVMerlino]

Related to my recent thread, how do we even know that mate in 7 is optimal? I mean, I believe that it is, but some engines here need 20+ or even 30+ depth to find mate in 7, how'd one know when the shortest mate is found?

Because I used Chessmaster's mate finder, and it took only five seconds to confirm that there was no mate in 6. But it took another fifty seconds to confirm the mate in 7.

[Chessnut1071]

Related to my recent thread, how do we even know that mate in 7 is optimal? I mean, I believe that it is, but some engines here need 20+ or even 30+ depth to find mate in 7, how'd one know when the shortest mate is found?

It might not be, if you want to be 100% sure about optimal paths for all possible positions, then you need to do alpha-beta without any other pruning/reductions. But that is going to be super slow

Super slow is right. I used an exhaustive, alpha-beta, 15-ply search, with Zobirst, history. and an evaluation with just check and SEE. You're looking at over 1.5 trillion engine calls. I would like to know what chessmaster uses to reduce that size.

[hgm]

Everything you said your engine didn't have I have. Although my engine is over 500x slower, we do get the same answer. Are using bit-boards? As far as C is concerned, I recently converted from VB.NET and only got a 10% increase in speed. Perhaps I need to optimize my C#. thx for the info

No, Fairy-Max is not bitboard. It uses a 16x8 mailbox board, and the move generator loops over all 64 board used elements to test whether they contain a piece of the player that is on move. This is a slow method, because at most 25% of those squares indeed contain such a piece. For this reason more advanced engines use a piece list next to the board array: the pieces in the board array are encoded as unique numbers, (rather than type), and these numbers can be used as index in the piece list, which tabulates the square that piece is on. Then you only have to loop through the (maximally 16) elements of the piece list section that holds the pieces of the side to move.

[j.t.]

I believe you should leave it for long enough to find a shorter mate

I though so too, but I didn't want to wait longer after Nalwald took more than 15 minutes to find a mate in 12 when it already found a mate in 11 after 10 seconds

[lithander]

MinimalChess 0.59 doesn't use reductions or extensions and finds a mate after 13 plys:

Code: Select all

position fen 5k2/ppp2r1p/2p2ppP/8/2Q5/2P1bN2/PP4P1/1K1R4 w - - 0 1
go
info string Search scheduled to take 715827862ms!
info depth 1 score cp 1001 nodes 117 nps 4034 time 29 pv c4b4
info depth 2 score cp 906 nodes 432 nps 12705 time 34 pv d1d8 f8e7
info depth 3 score cp 986 nodes 1410 nps 37105 time 38 pv d1d8 f8e7 d8d7
info depth 4 score cp 930 nodes 2878 nps 68523 time 42 pv c4b4 c6c5 b4b7 e3h6
info depth 5 score cp 987 nodes 5817 nps 103875 time 56 pv c4b4 c6c5 b4b7 e3h6 b7a8
info depth 6 score cp 974 nodes 19299 nps 189205 time 102 pv d1d8 f8e7 d8c8 e3b6 c8b8 f7f8
info depth 7 score cp 1130 nodes 33827 nps 194408 time 174 pv d1d8 f8e7 c4d3 f6f5 d8d7 e7e6 d7f7
info depth 8 score cp 1128 nodes 46310 nps 201347 time 230 pv d1d8 f8e7 c4d3 f6f5 d8d7 e7e6 d7f7 e6f7
info depth 9 score cp 1371 nodes 149765 nps 282575 time 530 pv d1d8 f8e7 d8c8 f7f8 c4e4 e7f7 c8c7 f7g8 e4e6
info depth 10 score cp 1328 nodes 227306 nps 334273 time 680 pv d1d8 f8e7 d8c8 f7f8 c4e4 e7d7 c8f8 e3h6 e4d4 d7e6
info depth 11 score cp 1456 nodes 678053 nps 407974 time 1662 pv d1d8 f8e7 d8c8 f7f8 c8c7 e7d6 c7b7 c6c5 c4d3 e3d4 d3a6
info depth 12 score cp 1425 nodes 1140933 nps 441025 time 2587 pv d1d8 f8e7 c4d3 f6f5 d8h8 e3c5 d3d8 e7e6 f3g5 e6e5 g5f7 e5e4
info depth 13 score mate 7 nodes 4437734 nps 479185 time 9261 pv c4e6 e3h6 d1d8 f8g7 f3e5 f6e5 e6e5 f7f6 d8d7 g7h8 e5f6 h8g8 f6f7
bestmove c4e6

But I don't think that this line does actually lead to a mate in 7 as reported but a mate in 8. I suppose QSearch just returns with an evaluation of Mate for the final position and so after 13 plys MinimalChess thinks it has reached a mate in 13 plys, not considering the moves that have been going on within QSearch. Do you guys extend the PV in Qsearch as well? Or how do you get the correct mate distance?