Author: Dann Corbit
Date: 09:48:19 06/08/05
Go up one level in this thread
On June 08, 2005 at 10:21:58, Christos Gitsis wrote:
>Some questions about that...
>
>What exactly is the DETECT_DRAW option of Crafty?
It sees walls that form.
>What other types of drawn positions can it detect?
Here is a famous one:
2b5/1r6/2kBp1p1/p2pP1P1/2pP4/1pP3K1/1R3P2/8 b - - bm Rb4; id "WAC.230";
Black(1): hash 512M
hash table memory = 384M bytes.
Black(1): hashp 256M
pawn hash table memory = 192M bytes.
Black(1): st 600
search time set to 600.00.
Black(1): epdpfga wac230.epd wac230.out
PFGA: EPD record: 1 ID: WAC.230
time surplus 0.00 time limit 10:00 (10:00)
depth time score variation (1)
9 0.14 -1.34 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kf4 Ka4 5. Bb2 Kb5
9-> 0.31 -1.34 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kf4 Ka4 5. Bb2 Kb5
10 0.53 -1.19 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kf4 Ka4 5. Bb2 Rh4+ 6. Kg3 Rh5
10-> 0.78 -1.19 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kf4 Ka4 5. Bb2 Rh4+ 6. Kg3 Rh5
11 1.09 -1.35 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kf4 Bd7 5. Rb2 Ka4 6. Bc5 Rh2
11-> 1.31 -1.35 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kf4 Bd7 5. Rb2 Ka4 6. Bc5 Rh2
12 1.58 +1 1. ... Rh7
12 1.87 0.00 1. ... Rh7 2. Rb1 Kb5 3. Ba3 Rh5 4.
Kg4 a4 5. f3 Bd7 6. Rb2 Kc6 7. Rb1
12 3.62 -1.23 1. ... Rb4 2. cxb4 a4 3. Rb1 c3 4.
b5+ Kxb5 5. Kf4 c2 6. Rc1 b2 7. Rxc2
b1=Q 8. Rc5+ Kb6 9. Rxc8
12-> 4.11 -1.23 1. ... Rb4 2. cxb4 a4 3. Rb1 c3 4.
b5+ Kxb5 5. Kf4 c2 6. Rc1 b2 7. Rxc2
b1=Q 8. Rc5+ Kb6 9. Rxc8
13 6.23 -1.19 1. ... Rb4 2. cxb4 a4 3. b5+ Kxb5 4.
Rb1 c3 5. Ra1 b2 6. Rb1 Kc4 7. Ba3
Kb3 8. Bxb2 c2 9. Rc1 <HT>
13-> 7.76 -1.19 1. ... Rb4 2. cxb4 a4 3. b5+ Kxb5 4.
Rb1 c3 5. Ra1 b2 6. Rb1 Kc4 7. Ba3
Kb3 8. Bxb2 c2 9. Rc1 <HT>
14 10.05 -1.19 1. ... Rb4 2. cxb4 a4 3. b5+ Kxb5 4.
Rb1 c3 5. Ra1 b2 6. Rb1 Kc4 7. Ba3
Kb3 8. Bxb2 c2 9. Rc1 Kxb2
14-> 12.48 -1.19 1. ... Rb4 2. cxb4 a4 3. b5+ Kxb5 4.
Rb1 c3 5. Ra1 b2 6. Rb1 Kc4 7. Ba3
Kb3 8. Bxb2 c2 9. Rc1 Kxb2
15 18.89 -1 1. ... Rb4!!
15 26.95 -1.92 1. ... Rb4 2. cxb4 a4 3. b5+ Kxb5 4.
Rb1 c3 5. Ba3 Kc4 6. Rh1 Bd7 7. Rd1
c2 8. Rc1 Kxd4 9. Bb2+ Ke4 10. f3+
Kf5
15-> 30.83 -1.92 1. ... Rb4 2. cxb4 a4 3. b5+ Kxb5 4.
Rb1 c3 5. Ba3 Kc4 6. Rh1 Bd7 7. Rd1
c2 8. Rc1 Kxd4 9. Bb2+ Ke4 10. f3+
Kf5
16 1:04 -2.07 1. ... Rb4 2. Rb1 Ra4 3. Rc1 Ra2 4.
Kf3 a4 5. Ke3 Ba6 6. f3 Bb5 7. Bc5
Rh2 8. Rb1 Rc2 9. Bb4
16-> 1:11 -2.07 1. ... Rb4 2. Rb1 Ra4 3. Rc1 Ra2 4.
Kf3 a4 5. Ke3 Ba6 6. f3 Bb5 7. Bc5
Rh2 8. Rb1 Rc2 9. Bb4
17 2:24 -2.06 1. ... Rb4 2. Rb1 Ra4 3. Rc1 Ra2 4.
Kf3 a4 5. Ke3 Ba6 6. f3 Bb5 7. Rh1
Rc2 8. Bb4 Kb6 9. Kf4 Rf2
17-> 2:44 -2.06 1. ... Rb4 2. Rb1 Ra4 3. Rc1 Ra2 4.
Kf3 a4 5. Ke3 Ba6 6. f3 Bb5 7. Rh1
Rc2 8. Bb4 Kb6 9. Kf4 Rf2
18 4:49 -2.11 1. ... Rb4 2. Rb1 Ra4 3. Rc1 Ra2 4.
Kf3 a4 5. Ke3 Ba6 6. f3 Bb5 7. Bc5
Rh2 8. Ba3 Rh5 9. Kf4 Rh4+ 10. Kg3
Rh5
18-> 5:42 -2.11 1. ... Rb4 2. Rb1 Ra4 3. Rc1 Ra2 4.
Kf3 a4 5. Ke3 Ba6 6. f3 Bb5 7. Bc5
Rh2 8. Ba3 Rh5 9. Kf4 Rh4+ 10. Kg3
Rh5
time=10:00 cpu=96% mat=-1 n=712290219 fh=88% nps=1.19M
ext-> chk=25589264 cap=619216 pp=5232529 1rep=1017059 mate=26718
predicted=0 nodes=712290219 evals=285917386 50move=0
endgame tablebase-> probes=0 hits=0
Result record:
2b5/1r6/2kBp1p1/p2pP1P1/2pP4/1pP3K1/1R3P2/8 b - - acd 19; acn 712290219; acs
600; bm Rb4; ce 211; id "WAC.230"; pv Rb4 Rb1 Ra4 Rc1 Ra2 Kf3 a4 Ke3 Ba6 f3 Bb5
Bc5 Rh2 Ba3 Rh5 Kf4 Rh4+ Kg3 Rh5;
Tragically, this beautiful move probably does not win, due to an equally
beautiful refutation discovered by Alex Szabo.
>What disadvantages does it have? (the "standard" executables that I have are
>obviously compiled with DETECT_DRAW disactivated)
It can make the engine play less strong in some situations.
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