chrisw wrote: ↑Thu Aug 23, 2018 1:44 pm
zullil wrote: ↑Thu Aug 23, 2018 12:57 am
George Tsavdaris wrote: ↑Thu Aug 23, 2018 12:40 am
In this interesting Lyudmil position, Stockfish has a huge fail high and went from
+10.33(a win for white) to
-mate in 12(black mates in 12).
It had a >+8.00 eval until it found the winning move for about 1.5 billion nodes and depth 32(not too easy to get great depth in this).
How other engines do on this?
Do you have other examples of huge fail lows/highs where engines change their evaluation so drastically?
[d]3r3k/1pNbb2p/1Pp2n2/P1Pp4/3Pp3/1QB1PpPr/2N2P2/2R2RK1 b - - 0 1
Not sure why this is surprising. After all, White is about a Queen ahead in material. So, of course, until the search discovers the mate for Black, the evaluation will be very much in favor of White.
What is "surprising" is how deep SF has to go before seeing black wins.
Indeed. Sf-dev's deterministic search (1 thread) examines more than 2 billion nodes before deciding on Rg8. And that's simply to find that the move is the least bad of its available options, not that the move is in any way good!
info depth 37 seldepth 60 multipv 1 score cp -1116 upperbound nodes 2217290410 nps 2475287 hashfull 999 tbhits 0 time 895771 pv h7h5 a5a6
info depth 37 currmove h7h5 currmovenumber 1
info depth 37 currmove h3h6 currmovenumber 2
info depth 37 currmove h3h1 currmovenumber 3
info depth 37 currmove d7g4 currmovenumber 4
info depth 37 currmove h8g8 currmovenumber 5
info depth 37 currmove h3h2 currmovenumber 6
info depth 37 currmove d8g8 currmovenumber 7
info depth 37 seldepth 60 multipv 1 score cp -1101 lowerbound nodes 2458504285 nps 2481317 hashfull 999 tbhits 0 time 990806 pv d8g8