Author: Dann Corbit
Date: 12:33:47 02/28/02
Go up one level in this thread
On February 28, 2002 at 15:00:03, Les Fernandez wrote:
>[D]8/4b1k1/R5pp/2p1pp2/1pQq4/1P1P3P/1P3PPK/8 w - -
>
>
>I am interested to know if the above position can be held by black. White is
>short on time but can force perpetual by Qe6. Although a rook is better then a
>bishop, most of the time, should white exchange queens here? I am only an
>average player but after doing a little analysis on this position Crafty reports
>the following on a fairly slow machine. (Pentium 350, 256 mb ram)
>
>8/4b1k1/R5pp/2p1pp2/1pQq4/1P1P3P/1P3PPK/8 w - - acd 15; acn 170618898; acs 900;
>ce 155; pv Kg1 Qxc4 bxc4 h5 g3 Kf7 Kg2 Bf6 Rc6 Be7 Kf3 g5;
>
>Although white is reported to have a 1.55 advantage after Kg1 I wonder if the
>position can be held by black. I also took a look at the position with white
>taking the queen and the ce still appeared about the same with black capturing
>white queen with cxd4.
>
>8/4b1k1/R5pp/2p1pp2/1p1Q4/1P1P3P/1P3PPK/8 b - - acd 17; acn 186582676; acs 902;
>ce -151; pv cxd4 Kg3 Kf7 Kf3 h5 Rc6 Bf6 Rb6 Be7 g3 Bf8 h4 Be7;
>
>Question is with queens off the board can the white rook start chopping up the
>black pawns while the black bishop exists? Can someone run this on better
>hardware and tkae it a bit deeper to see what falls out?
Despite an evaluation that thinks it is up a full piece, I think it is drawn.
A bit longer with crafty:
EPD Kit revision date: 1996.04.21
unable to open book file [e:\crafty\release/books.bin].
hash table memory = 48M bytes.
pawn hash table memory = 6M bytes.
EGTB cache memory = 32M bytes.
draw score set to 0.00 pawns.
choose from book moves randomly (using weights.)
choose from 5 best moves.
book learning enabled
result learning enabled
position learning enabled
threshold set to 9 pawns.
5 piece tablebase files found
19045kb of RAM used for TB indices and decompression tables
Crafty v18.13
White(1): hash 300M
hash table memory = 192M bytes.
White(1): st 999
search time set to 999.00.
White(1): epdpfga \les.epd les.out
PFGA: EPD record: 1
end-game phase
clearing hash tables
time surplus 0.00 time limit 16:39 (16:39)
nss depth time score variation (1)
6-> 0.23 2.94 1. Ra7 Kf6 2. Ra6+ Kg5 3. Re6 Qxc4
4. bxc4 Bf6 <HT>
7 0.30 2.88 1. Ra7 Kf6 2. Ra6+ Kg7 3. Qc2 h5 4.
Qe2 Bg5 <HT>
7 0.40 2.90 1. Qc2 h5 2. g3 Kf7 3. Qe2 Bg5 4. Kg2
7-> 0.76 2.90 1. Qc2 h5 2. g3 Kf7 3. Qe2 Bg5 4. Kg2
8 0.86 2.89 1. Qc2 h5 2. g3 Kf7 3. Qe2 Bg5 4. h4
Bf6
8 1.81 2.99 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 b3 5. f3
8-> 1.90 2.99 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 b3 5. f3
9 2.12 2.90 1. Kg1 Qxc4 2. bxc4 h5 3. f3 Kf7 4.
Kf2 h4 5. Ke3 b3
9-> 3.07 2.90 1. Kg1 Qxc4 2. bxc4 h5 3. f3 Kf7 4.
Kf2 h4 5. Ke3 b3
10 3.64 2.99 1. Kg1 Qxc4 2. bxc4 h5 3. g3 Bf6 4.
Ra5 Be7 5. Kg2 b3 6. Kf3
10-> 5.53 2.99 1. Kg1 Qxc4 2. bxc4 h5 3. g3 Bf6 4.
Ra5 Be7 5. Kg2 b3 6. Kf3
11 6.78 3.00 1. Kg1 Qxc4 2. bxc4 h5 3. g3 Kf7 4.
Kg2 g5 5. b3 h4 6. gxh4 gxh4 7. Kf3
11-> 10.16 3.00 1. Kg1 Qxc4 2. bxc4 h5 3. g3 Kf7 4.
Kg2 g5 5. b3 h4 6. gxh4 gxh4 7. Kf3
12 11.93 2.99 1. Kg1 Qxc4 2. bxc4 h5 3. g3 Kf7 4.
Kg2 g5 5. b3 h4 6. Kf3 Bf6 7. Ke3
12-> 26.95 2.99 1. Kg1 Qxc4 2. bxc4 h5 3. g3 Kf7 4.
Kg2 g5 5. b3 h4 6. Kf3 Bf6 7. Ke3
13 56.08 3.09 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 h4 5. g3 g5 6. Kf3 Bf6 7. Ra5 <HT>
13-> 1:25 3.09 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 h4 5. g3 g5 6. Kf3 Bf6 7. Ra5 <HT>
14 1:37 3.08 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 h4 5. g3 hxg3 6. fxg3 f4 7. Kf2
b3 8. Ra7 fxg3+ 9. Kxg3
14-> 3:57 3.08 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 h4 5. g3 hxg3 6. fxg3 f4 7. Kf2
b3 8. Ra7 fxg3+ 9. Kxg3
15 4:36 3.07 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 h4 5. g3 hxg3 6. fxg3 f4 7. Ra7
fxg3 8. Kf3 Ke6 9. Kxg3
15-> 9:01 3.07 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 h4 5. g3 hxg3 6. fxg3 f4 7. Ra7
fxg3 8. Kf3 Ke6 9. Kxg3
16 12:32 3.10 1. Kg1 Qxc4 2. bxc4 h5 3. Kf1 Kf7 4.
Ke2 Kg7 5. g3 Kf7 6. Ke3 Bg5+ 7. Kf3
Be7 8. Rc6 h4 9. gxh4 b3
time=16:39 cpu=100% mat=2 n=541204974 fh=90% nps=541k
ext-> chk=37748306 cap=1678048 pp=342348 1rep=3409275 mate=104978
predicted=0 nodes=541204974 evals=0
endgame tablebase-> probes done=0 successful=0
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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