Author: Vincent Diepeveen
Date: 05:07:37 01/04/02
Go up one level in this thread
On January 03, 2002 at 16:16:51, Robert Hyatt wrote: >On January 03, 2002 at 11:14:33, Uri Blass wrote: > >>This is analysis of Crafty under chessbase GUI >> >>New position >>[D]2r1k1r1/2p2pP1/1p5p/p3nP2/3N3B/P1P5/2q3PP/R3R1K1 b - - 0 1 >> >>Analysis by Crafty 18.12: >> >>4...Qxc3 5.Rxe5+ >> -+ (-2.05) Depth: 1/6 00:00:00 >>4...Qxc3 5.Rxe5+ Kd7 6.Re7+ Kd6 >> ยต (-1.16) Depth: 2/6 00:00:00 >> >>I am interested to know what is the remaining depth of Crafty after >>every move at depth 2. > > >I am assuming that when you start the above analysis, second line of output, >the depth is "2". > >If so, the initial depth is started at 2.5 (I kick in 1/2 ply so that the first >few fractional extensions will work). > >after Qxc3, the depth=1.5 > >after Rxe5, the depth is still 1.5 as I extend when checking rather than when >getting out of check to solve a problem of dropping into the q-search in check >which is bad if you don't do checks there. Check evasions are way better for hashtable. If you fear to drop to qsearch you only have to check at that depth whether you are in check. >If the move Kd7 is the only legal move, then the depth after it will be 1.25 >as it is extended 3/4 ply and 1.5 - 1 +.75 leaves the depth at 1.25 > >After The next check, the depth is still going to be 1.25 > >After getting out of check, the next depth will be .25 which is < 1.0 and >the search drops into the quiescence search and terminates there... > >Did that help??? > > > > >> >>I think that the only relevant extensions of Crafty for the pv is check >>extension and one reply to check extension(mate threat is not relevant at depth >>2,recapture is not at the same square and no pawn is pushed) >> >>Does it mean the following? >> >>1)The remaining depth after 4...Qxc3 is 1 because Qxc3 reduce 1 from the >>remaining depth >> >>2)The remaining depth after 5.Rxe5+ is 2 because after this move crafty extends >>for 2 reasons(check and single reply) so it add 2 to the remaining depth thanks >>toextension and reduce only 1 from the remaining depth as usual. >> >>3)The remaining depth after 5...Kd7 is 1 >> >>4)the remaining depth after 6.Re7+ is again 1(check extension) >> >>5)the remaining depth after 6...Kd6 is 0 >> >>6)Crafty has to evaluate and find no good capture for white so the pv ends at >>this point >> >>Uri
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