Author: Vincent Diepeveen
Date: 14:36:13 04/13/01
Go up one level in this thread
On April 13, 2001 at 13:09:53, Dann Corbit wrote: >Here is the position for WAC 230, after the key move Rb4... > >[D]2b5/8/2kBp1p1/p2pP1P1/1rpP4/1pP3K1/1R3P2/8 w - - bm Rb4; id "WAC.230 after >Rb4"; > >Here is some analysis performed on this position on a fast machine (still >on-going): > >book file enabled. >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. >4 piece tablebase files found >3358kb of RAM used for TB indices and decompression tables > >Crafty v18.9 (2 cpus) > >White(1): mt 2 >max threads set to 2 >White(1): st 86400 >search time set to 86400.00. >White(1): epdpfga wac230.epd wac230.out >PFGA: EPD record: 1 ID: WAC.230 after Rb4 >end-game phase > clearing hash tables > time surplus 0.00 time limit 1440:00 (1440:00) > nss depth time score variation (1) >starting thread 1 > 9 0.13 -- 1. cxb4 > 9 0.16 0.34 1. cxb4 a4 2. Rb1 Kb5 3. Ra1 c3 4. > Rc1 b2 5. Rxc3 b1=Q 6. Rxc8 <HT> > 9-> 0.17 0.34 1. cxb4 a4 2. Rb1 Kb5 3. Ra1 c3 4. > Rc1 b2 5. Rxc3 b1=Q 6. Rxc8 <HT> > 10 0.28 -- 1. cxb4 > 10 0.47 -0.76 1. cxb4 a4 2. b5+ Kxb5 3. Kf4 c3 4. > Rb1 c2 5. Rc1 b2 6. Rxc2 b1=Q 7. Rxc8 > 10-> 0.53 -0.76 1. cxb4 a4 2. b5+ Kxb5 3. Kf4 c3 4. > Rb1 c2 5. Rc1 b2 6. Rxc2 b1=Q 7. Rxc8 > 11 0.81 -0.76 1. cxb4 a4 2. b5+ Kxb5 3. Kf4 c3 4. > Rb1 c2 5. Rc1 b2 6. Rxc2 b1=Q 7. Rc5+ > Kb6 8. Rxc8 > 11-> 0.91 -0.76 1. cxb4 a4 2. b5+ Kxb5 3. Kf4 c3 4. > Rb1 c2 5. Rc1 b2 6. Rxc2 b1=Q 7. Rc5+ > Kb6 8. Rxc8 > 12 1.61 -1.14 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Rd1 b2 6. Rb1 Kb3 7. Bxb2 > cxb2 8. Kf4 <HT> > 12-> 1.83 -1.14 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Rd1 b2 6. Rb1 Kb3 7. Bxb2 > cxb2 8. Kf4 <HT> > 13 2.89 -- 1. cxb4 > 13 3.98 -1.69 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Rc1 Kc4 5. Ba3 Kxd4 6. Kf4 Kd3 7. Rd1+ > Kc4 <HT> > 13-> 4.58 -1.69 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Rc1 Kc4 5. Ba3 Kxd4 6. Kf4 Kd3 7. Rd1+ > Kc4 <HT> > 14 4.91 ++ 1. cxb4!! > 14-> 19.08 -1.30 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Rc1 Kc4 5. Ba3 Kxd4 6. Kf4 Kd3 7. Rd1+ > Kc4 <HT> > 15 24.17 -- 1. cxb4 > 15 32.22 -2.11 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Rc1 Kxd4 6. Bb4 c2 7. Ba3 > Kxe5 8. f4+ Ke4 9. Re1+ Kd3 10. Rc1 > 15-> 34.64 -2.11 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Rc1 Kxd4 6. Bb4 c2 7. Ba3 > Kxe5 8. f4+ Ke4 9. Re1+ Kd3 10. Rc1 > 16 44.41 -2.08 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Rc1 Kxd4 6. Kf4 Kd3 7. Rd1+ > Kc2 8. Rc1+ Kd2 9. Rh1 Bb7 10. f3 > 16-> 47.98 -2.08 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Rc1 Kxd4 6. Kf4 Kd3 7. Rd1+ > Kc2 8. Rc1+ Kd2 9. Rh1 Bb7 10. f3 > 17 1:18 -2.13 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. Rh1 Kd3 7. Rh3+ > Kd2 8. Bc1+ Kc2 9. Be3 b2 10. Bd4 b1=Q > 11. Rxc3+ Kd2 12. Rxc8 > 17-> 1:29 -2.13 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. Rh1 Kd3 7. Rh3+ > Kd2 8. Bc1+ Kc2 9. Be3 b2 10. Bd4 b1=Q > 11. Rxc3+ Kd2 12. Rxc8 > 18 2:34 -2.31 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. f3 Kd3 7. Rd1+ > Kc4 8. Rb1 d4 9. Rc1 Kd5 10. Rd1 Bd7 > 18-> 3:04 -2.31 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. f3 Kd3 7. Rd1+ > Kc4 8. Rb1 d4 9. Rc1 Kd5 10. Rd1 Bd7 > 19 6:36 -2.69 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. f3 Kd3 7. Rd1+ > Kc4 8. Rc1 d4 9. Ke4 Bd7 10. Bb2 Bc6+ > 11. Kf4 Kb4 12. Ba1 > 19-> 8:33 -2.69 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. f3 Kd3 7. Rd1+ > Kc4 8. Rc1 d4 9. Ke4 Bd7 10. Bb2 Bc6+ > 11. Kf4 Kb4 12. Ba1 > 20 12:14 ++ 1. cxb4!! > 20-> 167:02 -2.30 1. cxb4 a4 2. b5+ Kxb5 3. Rb1 c3 4. > Ba3 Kc4 5. Kf4 Kxd4 6. f3 Kd3 7. Rd1+ > Kc4 8. Rc1 d4 9. Ke4 Bd7 10. Bb2 Bc6+ > 11. Kf4 Kb4 12. Ba1 > 21 198:11 -2.38 1. cxb4 a4 2. b5+ Kxb5 3. Re2 c3 4. > Ba3 Kc4 5. f4 Kxd4 6. f5 exf5 7. e6 > Kd3 <HT> > 21-> 208:48 -2.38 1. cxb4 a4 2. b5+ Kxb5 3. Re2 c3 4. > Ba3 Kc4 5. f4 Kxd4 6. f5 exf5 7. e6 > Kd3 <HT> > 22 282:09 -2.28 1. cxb4 a4 2. b5+ Kxb5 3. Re2 c3 4. > Ba3 Kc4 5. f4 Kxd4 6. f5 exf5 7. e6 > Kd3 8. e7 Bd7 9. e8=Q Bxe8 10. Rxe8 > d4 11. Re5 Kd2 12. Re6 f4+ 13. Kxf4 > (3) 22-> 308:42 -2.28 1. cxb4 a4 2. b5+ Kxb5 3. Re2 c3 4. > Ba3 Kc4 5. f4 Kxd4 6. f5 exf5 7. e6 > Kd3 8. e7 Bd7 9. e8=Q Bxe8 10. Rxe8 > d4 11. Re5 Kd2 12. Re6 f4+ 13. Kxf4 > (2) 23 549:08 -2.15 1. cxb4 a4 2. b5+ Kxb5 3. Re2 c3 4. > Ba3 Kc4 5. f4 Kxd4 6. f5 exf5 7. e6 > Kd3 8. e7 Bd7 9. e8=Q Bxe8 10. Rxe8 > d4 11. Kf4 b2 12. Rb8 Kc2 13. Bxb2 > cxb2 > (2) 23-> 627:43 -2.15 1. cxb4 a4 2. b5+ Kxb5 3. Re2 c3 4. > Ba3 Kc4 5. f4 Kxd4 6. f5 exf5 7. e6 > Kd3 8. e7 Bd7 9. e8=Q Bxe8 10. Rxe8 > d4 11. Kf4 b2 12. Rb8 Kc2 13. Bxb2 > cxb2 I saw the previous postings too about the Rb4 being a win anyway and i was pretty amazed when i putted it at diep. After playing Rb4 cxb4 a4 b5 Kxb5 Ba3 c3 Re2 (all forced after rb4) Then when i let DIEP search overnight it first went up in score a bit, then at bigger depths it gets down near to zero too here. Very amazing. then i started analyzing all kind of lines but only got more complex questions. The position is not simple at all after this line. For sure however Rb4 is best move by a big margin, as the Rh7 move in the root position is not going to give winning chances. It is however a big mystery still whether Rb4 is winning or a draw in reality. There are many passer runs which black can try before it is any clearer whether Rb4 wins. Note that computers have major problems in seeing passer sequences, especially when we talk about around 5 passers on the board which occur after sequences with f4 f5, so the truth is long from revealed. Whatever happens, in all those lines white is NOT going to win. So Rb4 is obviously best move, usually Rb4 isn't best move because of the interesting above line though in progs, so still it's a cool test position! >This offers another permutation to ponder (white's response 3. Re2 is not >considered elsewhere...) > >Alex Szabo's pv went like this (after Rb4): >cxb4 a4 b5+ Kxb5 Ba3 c3 Re2! Kc4 f4 Kxd4 f5 exf5 ... > >It appears that we have merely a transposition in the crafty analysis and that >of Szabo. > >This line (and/or its transposition) deserves more scrutiny to be really sure if >it gives a true winning advantage or only results in a draw. > >The other lines clearly win. This is the only one left in question, I think.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.