Author: scott farrell
Date: 21:40:30 01/11/04
Go up one level in this thread
On January 11, 2004 at 17:55:11, Uri Blass wrote: >On January 11, 2004 at 16:52:09, Robert Hyatt wrote: > >>On January 11, 2004 at 15:47:04, Uri Blass wrote: >> >>>I do not see a word about promotions in swap.c of Crafty but maybe there is >>>something that I do not understand. >>> >>>Uri >> >>Swap() will only find capture promotions. It really doesn't do anything >>with them, because the value is a pawn, not a queen, and the normal Swap() >>code handles that just fine. IE if you treat it as simply dxe8, that is >>good enough, you are winning a piece. If your opponent re-captures, he >>only gets a pawn, not the queen you promoted to... > >If the pawn is pinned you may need to capture with something else. > >[D]rn6/P7/K7/8/8/6k1/1Q6/8 w - - 0 1 > >If I understand correctly >SEE of Crafty is going to consider QxN as a bad capture. > >Uri from chompster: the key to the numbers here is : maxthreat/SEE+/SEE/NA SEE is similar to crafty SEE + is my new version that understands pins/promos and other things you'll see that SEE+ notices the promo captures are bad (-37 losing the king) and that QxN is +3, it took me a while to work out it considers RxQ is bad because of PxR=Q, so it stops the SEE at QxN and returns +3. the -9 shows the Queen walking in front of bus. I have given it tougher positions that this, and most come out accurately - care to try again !! I think the only inaccuracy here is becuase of the promo + check, and it allows a stand-pat still, eg if its in check maybe I should disallow stand-pat in the SEE. Scott rn6/P7/K7/8/8/6k1/1Q6/8/ w - - 0 0 normal moves: PxN=Q (A7B8) , maxThreat=0/-37/3/0 PxN=R (A7B8) , maxThreat=0/-37/3/0 PxN=B (A7B8) , maxThreat=0/-37/3/0 PxN=N (A7B8) , maxThreat=0/-37/3/0 KB7 (A6B7) , maxThreat=5/0/0/0 KB6 (A6B6) , maxThreat=0/0/0/0 KA5 (A6A5) , maxThreat=0/0/0/0 KB5 (A6B5) , maxThreat=0/0/0/0 QxN (B2B8) , maxThreat=9/3/-1/0 QH8 (B2H8) , maxThreat=0/0/0/0 QB7 (B2B7) , maxThreat=5/0/0/0 QG7 (B2G7) , maxThreat=9/0/0/0 QB6 (B2B6) , maxThreat=0/0/0/0 QF6 (B2F6) , maxThreat=0/0/0/0 QB5 (B2B5) , maxThreat=0/0/0/0 QE5 (B2E5) , maxThreat=9/0/0/0 QB4 (B2B4) , maxThreat=0/0/0/0 QD4 (B2D4) , maxThreat=0/0/0/0 QA3 (B2A3) , maxThreat=9/0/0/0 QB3 (B2B3) , maxThreat=9/0/0/0 QC3 (B2C3) , maxThreat=9/0/0/0 QA2 (B2A2) , maxThreat=0/0/0/0 QC2 (B2C2) , maxThreat=0/0/0/0 QD2 (B2D2) , maxThreat=0/0/0/0 QE2 (B2E2) , maxThreat=0/0/0/0 QF2 (B2F2) , maxThreat=9/-9/-9/0 QG2 (B2G2) , maxThreat=9/-9/-9/0 QH2 (B2H2) , maxThreat=9/-9/-9/0 QA1 (B2A1) , maxThreat=0/0/0/0 QB1 (B2B1) , maxThreat=0/0/0/0 QC1 (B2C1) , maxThreat=0/0/0/0 ->1.0/1(2) 10.5 0.1secs 81 QxN+ RxQ
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