[d] 1rb4k/p5np/3p1rp1/1ppB4/2N2P2/1P2R1P1/P1P4P/4R1K1 w - -
discussed recently here:
http://www.chessgames.com/perl/chessgame?gid=1023099
bm is Re8+. This one is really difficult. Rybka 3 gets it after about 9 1/2 minutes on my older Athlon dual core.
--Jon
Bagirov-Grigorian, USSR 1976
Moderator: Ras
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jdart
- Posts: 4420
- Joined: Fri Mar 10, 2006 5:23 am
- Location: http://www.arasanchess.org
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CThinker
- Posts: 388
- Joined: Wed Mar 08, 2006 10:08 pm
Re: Bagirov-Grigorian, USSR 1976
On a 1.2ghz notebook, and in debug mode, Active Thinker finds it in 16 seconds. With 2 threads on the same notebook, Active Thinker finds it in 5 to 10 seconds (it depends on how threads are scheduled).jdart wrote:[d] 1rb4k/p5np/3p1rp1/1ppB4/2N2P2/1P2R1P1/P1P4P/4R1K1 w - -
discussed recently here:
http://www.chessgames.com/perl/chessgame?gid=1023099
bm is Re8+. This one is really difficult. Rybka 3 gets it after about 9 1/2 minutes on my older Athlon dual core.
--Jon
Passive Thinker never finds it at all (I give up after a few minutes).
Its interesting to see how differences in Eval affect this behavior.
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bob
- Posts: 20943
- Joined: Mon Feb 27, 2006 7:30 pm
- Location: Birmingham, AL
Re: Bagirov-Grigorian, USSR 1976
I thought this one might turn out to be too easy...jdart wrote:[d] 1rb4k/p5np/3p1rp1/1ppB4/2N2P2/1P2R1P1/P1P4P/4R1K1 w - -
discussed recently here:
http://www.chessgames.com/perl/chessgame?gid=1023099
bm is Re8+. This one is really difficult. Rybka 3 gets it after about 9 1/2 minutes on my older Athlon dual core.
--Jon
Code: Select all
20 42.29 1.22 1. Nd2 Rf5 2. c4 bxc4 3. bxc4 Rf8 4.
Re7 a6 5. Nf3 Rb6 6. Ng5 h6 7. Nf7+
Kh7 8. a4 a5 9. Kh1 Ba6 10. g4 Rfb8
11. g5
20 47.37 +1 1. Re8+!! (15.0Mnps)
20 56.16 +3 1. Re8+!! (17.0Mnps)
20 1:09 3.18 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 c4 5. bxc4 a6 6. h4 bxc4 7.
Kf2 Rf5 8. Nxf5+ gxf5 9. Bxc4 Ra8 10.
Rd8 Kg7 11. Ke3 a5 12. Be6 Bxe6 13.
Rxa8 <HT>
20-> 1:09 3.18 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 c4 5. bxc4 a6 6. h4 bxc4 7.
Kf2 Rf5 8. Nxf5+ gxf5 9. Bxc4 Ra8 10.
Rd8 Kg7 11. Ke3 a5 12. Be6 Bxe6 13.
Rxa8 <HT> (s=2)
21 1:15 +1 1. Re8+!! (18.1Mnps)
21 1:22 3.67 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 c4 5. bxc4 bxc4 6. Kf2 Rf5 7.
Nxf5+ gxf5 8. Bxc4 Ra8 9. Bd5 Rb8 10.
Bc6 d5 11. Bd7 Bxd7 12. Rxb8 Kg6 13.
Ra8 Ba4 14. Rxa7 Bxc2
21-> 1:24 3.67 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 c4 5. bxc4 bxc4 6. Kf2 Rf5 7.
Nxf5+ gxf5 8. Bxc4 Ra8 9. Bd5 Rb8 10.
Bc6 d5 11. Bd7 Bxd7 12. Rxb8 Kg6 13.
Ra8 Ba4 14. Rxa7 Bxc2
22 1:44 3.93 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 b4 5. Kf2 g5 6. f5 Bxf5 7. Rxb8
Bxc2+ 8. Ke2 Bf5 9. Rd8 Kg6 10. Nc4
Be6 11. Rxd6 Bg4+ 12. Ke3 Rxd6 13.
Nxd6 Kf6 14. Be4 h5
22-> 1:46 3.93 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 b4 5. Kf2 g5 6. f5 Bxf5 7. Rxb8
Bxc2+ 8. Ke2 Bf5 9. Rd8 Kg6 10. Nc4
Be6 11. Rxd6 Bg4+ 12. Ke3 Rxd6 13.
Nxd6 Kf6 14. Be4 h5
23 2:05 3.80 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 b4 5. Kf2 g5 6. f5 Bxf5 7. Rxb8
Bxc2+ 8. Kg2 Bf5 9. Rd8 Kg6 10. Nc4
Bd3 11. Nxd6 g4 12. Rg8+ Kh5 13. Rd8
Bf1+ 14. Kg1 Bd3 15. Kg2 <HT>
23-> 2:10 3.80 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 b4 5. Kf2 g5 6. f5 Bxf5 7. Rxb8
Bxc2+ 8. Kg2 Bf5 9. Rd8 Kg6 10. Nc4
Bd3 11. Nxd6 g4 12. Rg8+ Kh5 13. Rd8
Bf1+ 14. Kg1 Bd3 15. Kg2 <HT>
time=2:38 mat=0 n=2928166605 fh=92% nps=18.5M
ext-> check=87.0M qcheck=112.9M 1rep=6.5M mate=6.5M reduce=1483.8M
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bob
- Posts: 20943
- Joined: Mon Feb 27, 2006 7:30 pm
- Location: Birmingham, AL
Re: Bagirov-Grigorian, USSR 1976
BTW, here is a _very_ interesting test everyone ought to try. Run this position until you find the best move (Re8+). Then go back and run it again, but only search Re8 at the root, and see how many plies earlier you get the score jump. That tells you what your reductions / null-move /etc is "hiding" from you. Here is mine:
So in my case I lose a ply with the reductions and stuff. less than I thought for this position. I'd prefer to lose nothing and find re8 at depth 19 with a full search.
Code: Select all
18-> 2.86 1.05 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 a5 5. h3 a4 6. bxa4 bxa4 7.
Kg2 a3 8. Ng4+ Bxg4 9. hxg4 Rxg8 10.
g5+ Kg7 11. gxf6+ Kf8 12. Bxg8 Kxg8
13. Kf3
19 5.11 +1 1. Re8+!! (14.2Mnps)
19 6.26 +3 1. Re8+!! (15.2Mnps)
19 13.85 3.11 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 b4 5. h4 Rf5 6. Kf2 Rxd5 7.
Nxd5 Be6 8. Rxb8 Bxd5 9. Rd8 Be4 10.
Rxd6 Bxc2 11. Rc6 Kg7 12. Rxc5
19-> 13.85 3.11 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6
4. Ne3 b4 5. h4 Rf5 6. Kf2 Rxd5 7.
Nxd5 Be6 8. Rxb8 Bxd5 9. Rd8 Be4 10.
Rxd6 Bxc2 11. Rc6 Kg7 12. Rxc5
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Marc MP
Re: Bagirov-Grigorian, USSR 1976
Fritz 8 took a little more than an hour on my P4 3.2Ghz:jdart wrote:[d] 1rb4k/p5np/3p1rp1/1ppB4/2N2P2/1P2R1P1/P1P4P/4R1K1 w - -
discussed recently here:
http://www.chessgames.com/perl/chessgame?gid=1023099
bm is Re8+. This one is really difficult. Rybka 3 gets it after about 9 1/2 minutes on my older Athlon dual core.
--Jon
Code: Select all
1.Nd2 Rf5 2.c4 bxc4 3.bxc4 Rf8 4.Re7 a6 5.Nf3 Rb6 6.Ra7 Nh5 7.Ng5 Nf6 8.Ree7 Rb1+ 9.Kf2
+- (1.64) Depth: 18/45 00:58:53 2023mN
1.Re8+!
+- (1.64) Depth: 18/45 01:04:59 2271mN
1.Re8+!
+- (1.80) Depth: 18/45 01:05:02 2273mN
1.Re8+ Nxe8 2.Rxe8+ Kg7 3.Rg8+ Kh6 4.Ne3 b4 5.h4 Rf5 6.Nxf5+ gxf5 7.Be6 Bxe6 8.Rxb8 Kg6 9.Ra8
+- (2.01) Depth: 18/45 01:05:34 2296mN
1.Re8+!
+- (2.29) Depth: 19/39 01:07:08 2359mN
1.Re8+!
+- (2.57) Depth: 19/39 01:07:36 2377mN
1.Re8+ Nxe8 2.Rxe8+ Kg7 3.Rg8+ Kh6 4.Ne3 b4 5.Kf2 g5 6.f5 Bxf5 7.Rxb8 Be6+ 8.Kg2 Bxd5+
+- (2.88) Depth: 19/40 01:09:05 2438mN-
Marc MP
Re: Bagirov-Grigorian, USSR 1976
Here are Crafty-22.1 JA, E.T. Chess and Frenzee Feb08 on the same P4:
Code: Select all
Crafty-22.1 JA
22 +1.91 851.9M 20:12.55 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6 4. Na5 Rf5 5. Bg2 d5 6. Bh3 Rf7 7. Rxc8 Rxc8 8. Bxc8 Kg7 9. Nb7 Rc7 10. Nd6 Rc6 11. Ne8+ Kf7 12. Bd7 Ra6 13. Bxb5 Rxa2 14. Nc7 Rxc2 15. Nxd5
21 +1.90 722.0M 17:13.88 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6 4. Na5 Rf5 5. Bg2 d5 6. Bh3 Rf7 7. Rxc8 Rxc8 8. Bxc8 Kg7 9. Be6 Rf6 10. Bxd5 Ra6 11. b4 Rd6 12. Bc6 cxb4 13. Bxb5
21 +1.90 609.2M 14:35.63 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6 4. Na5 Rf5 5. Bg2 d5 6. Bh3 Rf7 7. Rxc8 Rxc8 8. Bxc8 Kg7 9. Be6 Rf6 10. Bxd5 Ra6 11. b4 Rd6 12. Bc6 cxb4 13. Bxb5
20 +1.68 537.3M 13:11.41 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6 4. Na5 Rf5 5. Bg2 d5 6. Bh3 Rf7 7. Bxc8 Rc7 8. Be6 Rxg8 9. Bxg8 d4 10. Bd5 Re7 11. Nb7 c4 12. Nd6 cxb3 13. cxb3
20 +1.68 494.5M 12:14.03 1. Re8+ Nxe8 2. Rxe8+ Kg7 3. Rg8+ Kh6 4. Na5 Rf5 5. Bg2 d5 6. Bh3 Rf7 7. Bxc8 Rc7 8. Be6 Rxg8 9. Bxg8 d4 10. Bd5 Re7 11. Nb7 c4 12. Nd6 cxb3 13. cxb3
20 +1.54 447.9M 11:15.74 1. Re8+!!
20 +1.14 420.9M 10:43.00 1. Nd2 Rf5 2. Bg2 Rf7 3. c4 Ba6 4. Bd5 Rc7 5. Re7 Rbc8 6. g4 Rxe7 7. Rxe7 bxc4 8. bxc4 Rf8 9. Rxa7 Bc8 10. f5 gxf5
E.T.Chess
19 +1.62 765.6M 41:26.29 Re8+ Nxe8 Rxe8+ Kg7 Rg8+ Kh6 Na5 Rf5 Bg2 d5 Bh3 Rf6 Bxc8 b4 h3
19 +1.62 674.2M 36:54.82 Re3e8 1/44 (304K/s)
18 +1.55 645.6M 35:37.68 Re8+ Nxe8 Rxe8+ Kg7 Rg8+ Kh6 Na5 Rf5 Bg2 d5 Bh3 Rf7 Rxc8 Rxc8 Bxc8 Re7 Kf2
18 +1.55 621.7M 34:22.09 Re3e8 1/44 (301K/s)
18 +1.41 608.2M 33:45.53 ++ Re8+ Nxe8 Rxe8+ Kg7 Rg8+ Kh6 Na5 Rf5 Bg2 d5 Bh3 Ra8 Bxf5 gxf5 Nc6 Bb7 Nd8 Rb8 Nf7+ Kh5 Rxb8
18 +1.41 608.2M 33:45.51 Re3e8 3/44 (300K/s)
18 +1.10 605.9M 33:38.76 + Re3e8 3/44 (300K/s)
18 +1.09 580.5M 32:14.79 Nc4d2 1/44 (300K/s)
Frenzee Feb08
20 +3.69 1380.5M 37:50.25 1.Re8+ Nxe8 2.Rxe8+ Kg7 3.Rg8+ Kh6 4.Na5 Rf5 5.Bg2 d5 6.Bh3 Ra8 7.Bxf5 gxf5 8.Nc6 Bb7 9.Nd8 Rxd8 10.Rxd8 d4 11.Rd6+ Kh5 12.Rd7 Be4 13.Rxh7+ Kg6 14.Rc7 Bxc2 15.Rc6+ Kh5
19 +3.53 1241.2M 33:57.07 1.Re8+ Nxe8 2.Rxe8+ Kg7 3.Rg8+ Kh6 4.Na5 Rf5 5.Bg2 d5 6.Bh3 Rf6 7.Rxc8 Rxc8 8.Bxc8 Kg7 9.Kf2 d4 10.Nb7 c4 11.bxc4 Rc6 12.Bg4 Rxc4 13.Bd1 Rc6 14.Kf3 Kf6 15.Ke4
19 +2.16 1192.0M 32:35.68 1.Re8+
19 +1.66 1181.7M 32:18.22 1.Re8+
19 +1.65 1103.3M 30:23.25 1.Nd2 Rf5 2.c4 Bb7 3.Bxb7 Rxb7 4.Ne4 Rb6 5.Rd1 Rf8 6.Nxd6 Rxd6 7.Rxd6 Nf5 8.Red3 Nxd6 9.Rxd6 bxc4 10.bxc4 Rb8 11.Rc6 Rb1+ 12.Kg2 Rb2+ 13.Kh3 Rxa2 14.Rxc5 h6 15.Rc7 a5 16.Rd7