mgv77 the four hard ones

Dann Corbit · Post by **Dann Corbit** » Wed Mar 10, 2010 8:52 am

Is there an engine that definitely chooses the proposed best move and holds it for some time? These seem to be especially difficult.

Code: Select all

8/3bkpp1/pp2p3/1P1pP2r/P2K3P/3B4/2P2P2/R7 w - -                  bm a5; hmvc 0; fmvc 1; id "MGV22-E: MOROZEVICH - Vallejo Pons, 1997";
8/5p2/r1k3p1/7p/2PK1P1P/1R4P1/8/8 w - -                          bm c5; hmvc 0; fmvc 1; id "GER - GER";
r2qkb1r/3bpppp/p4nn1/3P4/1p1N4/1QN3B1/PP3PPP/R3KB1R w KQkq -     bm Nc6; hmvc 0; fmvc 1; id "MGV35-P: SOLOVJOV - Kharitonov 2005";
r3r1k1/2qb1pp1/pp2n1np/2p1P3/2R1N3/1B3N1P/PP1Q1PP1/4R1K1 w - -   bm Nf6+; hmvc 0; fmvc 1; id "MGV70-K: NUNN - Smeets Amsterdam 2006";

Dann Corbit · Post by **Dann Corbit** » Wed Mar 10, 2010 11:04 am

Third one is solved by Stockfish in a reasonable time.

Vinvin · Post by **Vinvin** » Wed Mar 10, 2010 4:56 pm

With diag :[d]8/3bkpp1/pp2p3/1P1pP2r/P2K3P/3B4/2P2P2/R7 w - - bm a5; hmvc 0; fmvc 1; id "MGV22-E: MOROZEVICH - Vallejo Pons, 1997";
[d]8/5p2/r1k3p1/7p/2PK1P1P/1R4P1/8/8 w - - bm c5; hmvc 0; fmvc 1; id "GER - GER";
[d]r2qkb1r/3bpppp/p4nn1/3P4/1p1N4/1QN3B1/PP3PPP/R3KB1R w KQkq - bm Nc6; hmvc 0; fmvc 1; id "MGV35-P: SOLOVJOV - Kharitonov 2005";
[d]r3r1k1/2qb1pp1/pp2n1np/2p1P3/2R1N3/1B3N1P/PP1Q1PP1/4R1K1 w - - bm Nf6+; hmvc 0; fmvc 1; id "MGV70-K: NUNN - Smeets Amsterdam 2006";

zullil · Post by **zullil** » Wed Mar 10, 2010 6:18 pm

Dann Corbit wrote:Is there an engine that definitely chooses the proposed best move and holds it for some time? These seem to be especially difficult.

Stockfish-1.6.3 (8 threads) gets the fourth:

[d]r3r1k1/2qb1pp1/pp2n1np/2p1P3/2R1N3/1B3N1P/PP1Q1PP1/4R1K1 w - -

Code: Select all

Searching: r3r1k1/2qb1pp1/pp2n1np/2p1P3/2R1N3/1B3N1P/PP1Q1PP1/4R1K1 w - -
infinite: 1 ponder: 0 time: 0 increment: 0 moves to go: 0
 2     +0.85   00:01      460 Nd6 Red8 
 3     +1.05   00:01      982 Nd6 Red8 Bc2 
 4     +0.93   00:01     1516 Nd6 Red8 Bc2 Bc6 
 5     +1.29   00:01     2480 Nd6 Red8 Bc2 Bc6 Rg4 
 6     +1.21   00:01     4510 Nd6 Red8 Bc2 Bc6 Rg4 Bxf3 gxf3 
 7     +1.29   00:01    24768 Nd6 Re7 Bc2 Bc6 Rg4 Bxf3 gxf3 
 8  <  +1.05   00:01    42417 Nd6 Re7 Rg4 b5 Bd5 Bc6 
 9     +1.17   00:01   243894 Nd6 Rf8 h4 Bc6 Rg4 Bxf3 Rxg6 Bh5 Rg3 Bg6 
10     +1.21   00:01   843364 Nd6 Rf8 Rg4 Rad8 Nxf7 Rxf7 Rxg6 c4 Rc1 Bc6 Qb4 
                              Bxf3 Rxe6 
11     +1.17   00:01    1473k Nd6 Re7 Rg4 Bc6 Qd3 Rd8 Rxg6 fxg6 Qxg6 Qd7 Bc2 
                              Nf4 Qh7+ Kf8 
12  >  +1.37   00:01    2226k Nd6 Re7 Rg4 Bc6 Qd3 Rd8 Rxg6 fxg6 Qxg6 Qd7 Nf5 
                              Ree8 Ng5 hxg5 Nh6+ 
13     +1.29   00:01    3917k Nd6 Re7 Rg4 Bc6 Qd3 Ngf4 Qe3 Ng6 Bc2 h5 Rxg6 fxg6 
                              Bxg6 Bd5 b3 
14     +1.17   00:02    7930k Nd6 Re7 Rg4 Rd8 Qc2 b5 Nf5 Ree8 Nd6 Re7 Rxg6 fxg6 
                              Qxg6 Qa5 Bd5 
15     +1.13   00:04   17873k Nd6 Re7 Rg4 Bc6 Qd3 Ngf4 Qe3 Ng6 Bc2 Nd4 Bxg6 
                              Bxf3 Rxd4 cxd4 Qxf3 Rd8 Nxf7 Rxf7 Qb3 Rf8 f4 Qc5 
                              Bxf7+ Rxf7 
16  >  +1.33   00:05   26331k Nd6 Re7 Rg4 Bc6 Qd3 Ngf4 Qe3 Ng6 Bc2 Nd4 Bxg6 
                              Bxf3 Rxd4 cxd4 Qxf3 Rd8 Nxf7 Rxf7 Qb3 Rf8 f4 Qc5 
                              Rd1 
17     +1.45   00:07   43500k Nd6 Re7 Rg4 Bc6 Rxg6 fxg6 Nh4 b5 Nxg6 Ree8 Qe3 c4 
                              Bc2 Qa7 Qxa7 Rxa7 Nxe8 Bxe8 Bf5 Bxg6 Bxg6 
18     +1.66   00:24  170805k Nd6 Re7 Rg4 b5 Rxg6 fxg6 Nh4 c4 Nxg6 Ree8 Bc2 
                              Rad8 Rd1 Bc6 Qe3 Qa5 a4 bxa4 Nxe8 Rxd1+ Bxd1 Bxe8 
                              Bg4 Bxg6 Bxe6+ Bf7 
19     +1.58   00:37  272956k Nd6 Re7 Rg4 b5 Nf5 Ree8 Nd6 Bc6 Nh4 c4 Bc2 Nxh4 
                              Nxe8 Rxe8 Rxh4 Rd8 Qc3 Qe7 Rg4 h5 Rg3 Nf4 Bf5 
20     +1.62   01:29  661259k Nd6 Re7 Rg4 Rd8 Nf5 Ba4 Nxe7+ Qxe7 Qc2 Bxb3 Qxb3 
                              b5 Qe3 h5 Re4 c4 Nd4 Qc5 Nxe6 Qxe3 fxe3 fxe6 Rd4 
                              Rf8 Rd6 Nxe5 Rxa6 
21     +1.54   01:55  852728k Nd6 Re7 Rg4 Rd8 Nf5 Ba4 Nxe7+ Qxe7 Qc2 Bxb3 Qxb3 
                              b5 Qe3 h5 Re4 Rd5 Rc1 Qd8 b3 Rd3 Qe1 Ngf4 Re3 Rd5 
                              Qc3 Nd3 
22     +1.62   03:15    1441M Nd6 Re7 Rg4 Rd8 Nf5 Ba4 Nxe7+ Qxe7 Qc2 Bxb3 Qxb3 
                              b5 Qe3 h5 Re4 Rd5 Qc1 c4 Rd1 Rxd1+ Qxd1 Ngf4 Qc2 
                              Nd3 b3 Nec5 Re2 Nb4 Qf5 c3 Qxh5 
22  >  +1.74   04:07    1839M Nf6+ gxf6 Qxh6 f5 Nh4 Bc6 Nxf5 Red8 Rg4 Bd5 h4 
                              Bxb3 axb3 
23  >  +2.63   12:27    5623M Nf6+ Kh8 Ree4 gxf6 exf6 Ng5 Nxg5 hxg5 Qxg5 Kg8 
                              Rxe8+ 
Nodes: 7338331557
Nodes/second: 7530734
Best move: Nf6+
Ponder move: Kh8

Marc MP · Post by **Marc MP** » Thu Mar 11, 2010 2:38 am

Dann Corbit wrote:Is there an engine that definitely chooses the proposed best move and holds it for some time? These seem to be especially difficult.

Code: Select all

8/3bkpp1/pp2p3/1P1pP2r/P2K3P/3B4/2P2P2/R7 w - -                  bm a5; hmvc 0; fmvc 1; id "MGV22-E: MOROZEVICH - Vallejo Pons, 1997";
8/5p2/r1k3p1/7p/2PK1P1P/1R4P1/8/8 w - -                          bm c5; hmvc 0; fmvc 1; id "GER - GER";
r2qkb1r/3bpppp/p4nn1/3P4/1p1N4/1QN3B1/PP3PPP/R3KB1R w KQkq -     bm Nc6; hmvc 0; fmvc 1; id "MGV35-P: SOLOVJOV - Kharitonov 2005";
r3r1k1/2qb1pp1/pp2n1np/2p1P3/2R1N3/1B3N1P/PP1Q1PP1/4R1K1 w - -   bm Nf6+; hmvc 0; fmvc 1; id "MGV70-K: NUNN - Smeets Amsterdam 2006";

[d]8/3bkpp1/pp2p3/1P1pP2r/P2K3P/3B4/2P2P2/R7 w - -

Nice surprise! Pro Deo 1.6 - default on my PIV 3.2GHZ

Code: Select all

00:00:00.5	 -0,10	1	bxa6 Rxh4+ Ke3 Rxa4 
00:00:00.5	  0,09	1	Rh1 
00:00:00.5	  0,08	2	Rh1 axb5 axb5 
00:00:00.6	  0,11	3	Rh1 axb5 axb5 Be8 
00:00:00.6 -0,50	4      Rh1 axb5 Be2 Rf5 
00:00:00.6	 -0,50	4	bxa6 
00:00:00.6	  0,28	4	bxa6 Rxh4+ Ke3 Bc6 
00:00:00.6	  0,23	5	bxa6 Rxh4+ Kc3 d4+ Kc4 Bc6 
00:00:00.6	  0,34	6      bxa6 Rxh4+ Kc3 d4+ Kc4 Bc6 Rg1 
00:00:00.6	  0,76	7	bxa6 Rxh4+ Kc3 d4+ Kc4 Bc6 Rb1 Bd5+ Kb5 Rf4 Kxb6 Rxf2 

00:00:00.7  0,28	8      bxa6 Rxh4+ Ke3 Rxa4 Rxa4 Bxa4 a7 Bc6 Bb5 Ba8 f4 

00:00:00.9  0,31	9	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 g5 

00:00:01.1	  0,29	10	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 Kd4 Kc7 

00:00:01.8	  0,29	11    bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 Kd4 Kc7 

00:00:02.6	  0,23	12	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 Kd4 Kc7 Be8 f6 

00:00:04.9	  0,23	13	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 Kd4 Kc7 Be8 f6 

00:00:11.4	  0,30	14	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 Kd4 Kc7 Be8 f6 Bf7 Kd7 Bg6 

00:00:27.0	  0,14	15	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 f6 exf6+ Kxf6 Kb4 Bxa4 Kxa4 g5 a7 g4 

00:01:13.8	  0,14	16	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 Kd4 Kc7 Be8 f5 Bf7 Kd7 f4 Bc6 a7 Ba8 Bh5 Bb7 

00:03:23.2	  0,22	17	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Ba8 Kc3 Kd8 f4 Kc8 Kd4 Kc7 Be8 f6 Bb5 Bc6 a7 Ba8 Be2 Bb7 

00:08:13.7    0,20	18	bxa6 Rxh4+ Kc3 Rxa4 Rxa4 Bxa4 Kb4 Bc6 Bb5 Bd7 Bxd7 Kxd7 a7 f5 

00:15:54.2	   0,20	18	a5 

00:26:31.8   0,63	18	a5 Rxh4+ Kc3 bxa5 bxa6 a4 a7 Rh8

On the same hardware, FireBird 1.2 with the 5 mens TribleBases after 7 hours:

Code: Select all

1.bxa6 Rxh4+ 2.Kc3 Bc6 3.a7 Kd7 4.a5 bxa5 5.Rxa5 Rh8 6.Kd4 Kc7 7.Kc5 Ba8 8.Rb5 Bb7 9.Rb4 g5 10.Rg4 Ra8 11.Rxg5 Rxa7 12.Rg7 Ra5+ 13.Kb4 Kb6 14.Rxf7 Bc8 15.Rf6 Ra2 16.f3 Kc7 
  ±  (1.28)   Depth: 33   07:36:32  15428mN, tb=38773706

Eelco de Groot · Post by **Eelco de Groot** » Thu Mar 11, 2010 5:43 am

Only at depth 26 does Rainbow Serpent switch to the solution. But I'm sure a5 is the best move:

[d]8/3bkpp1/pp2p3/1P1pP2r/P2K3P/3B4/2P2P2/R7 w - - bm a5; hmvc 0; fmvc 1; id "MGV22-E: MOROZEVICH - Vallejo Pons, 1997";

Engine: Rainbow Serpent 1.6.3s(dc) Build 182 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

1.00 0:00 +0.08 1.bxa6 (967) 4

2.00 0:00 +0.08 1.bxa6 Rxh4+ 2.Ke3 Bxa4 3.a7 (3.195) 13

3.00 0:00 +0.24 1.bxa6 Rxh4+ 2.Ke3 Bc6 3.f4 (8.525) 36

4.00 0:00 +0.20 1.bxa6 Rxh4+ 2.Ke3 Bc6 3.c3 Kd7 4.a5 (36.130) 121

5.00 0:00 +0.40 1.bxa6 Rxh4+ 2.Ke3 Bc6 3.Rg1 g6
4.Bb5 d4+ 5.Kd3 Ba8 6.a7 Kd8 (58.679) 178

6.00 0:00 +0.44 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Bb5 d4+
4.Kb4 Ba8 5.Rd1 Kd8 (199.684) 354

7.00 0:00 +0.16-- 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Bb5 Ba8
4.Rg1 g6 5.a7 Kd8 (295.770) 411

8.00 0:00 +0.24 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Bb5 Ba8
4.Rg1 g6 5.Kd3 Kd8 6.c3 Rf4 7.Rh1 Rf3+
8.Kd4 Rxf2 9.Rh8+ (450.369) 457

9.01 0:02 +0.20 1.bxa6 Rxh4+ 2.Ke3 Bc6 3.c3 Kd7 4.a5 Rh3+
5.f3 bxa5 6.Rxa5 Kc7 7.Ra1 Kb6 8.a7 Ba8
9.Rb1+ Kc7 10.Rb8 (1.095.500) 539

10.01 0:04 +0.48 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kd4 Kc7 7.f4 Ba8
8.c4 dxc4 9.Rxc4+ Bc6 10.Rb4 Ba8
11.Bb5 (2.732.336) 571

11.01 0:05 +0.32 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Kc3 Ra1 10.Rb4 Kd7
11.f4 (3.054.659) 576

12.01 0:05 +0.20 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Kc3 Ra1 10.Rb4 Kd7
11.f4 Kc7 12.Kd4 (3.297.886) 578

13.01 0:07 +0.52 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 Bb5 8.Bxb5+ Rxb5+ 9.Ka3 Ra5+
10.Ra4 Rxa4+ 11.Kxa4 Kc7 12.Kb5 Kb8
13.Kb6 d4 14.Kc5 (4.578.294) 589

14.01 0:10 +0.52 1.bxa6 Rxh4+ 2.Kc3 Rxa4 3.Rxa4 Bxa4
4.a7 Bc6 5.Bh7 Ba8 6.Kd4 Kd7 7.Bg8 f6
8.c3 Ke7 9.f3 Kd7 10.f4 b5 11.Bf7 (6.539.226) 610

15.01 0:13 +0.48 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Rh4 d4 10.Rxd4 Rxe5
11.Kc3 Rh5 12.f4 e5 13.fxe5 Rxe5 (8.043.013) 618

16.01 0:18 +0.68++ 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Rh4 d4 10.Rxd4 Rxe5
11.Kc3 Ra5 12.Kb4 (11.821.855) 623

17.01 0:25 +0.68 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Rh4 d4 10.Rxd4 Rxe5
11.Kc3 Ra5 12.Kb4 Ra1 13.Kc5 e5
14.Rd6 (15.791.882) 631

18.01 0:52 +0.80 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Rh4 d4 10.Rxd4 Rxe5
11.Kc3 Rh5 12.Kb4 e5 13.Rc4 Kd7
14.a7 (33.689.309) 639

19.01 1:20 +0.72 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Rh4 d4 10.Rxd4 Rxe5
11.Kc3 Re1 12.Rc4 Bd7 13.Rb4 Ra1
14.Rb6 (51.577.898) 644

20.01 2:05 +0.76 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Rh4 g5 10.Rg4 f6
11.exf6+ Kxf6 12.Rg3 e5 13.Be2 d4
14.Ra3 (81.613.808) 648

21.01 3:23 +0.76 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Kc3 Ra3+ 10.Kd2 Ra1
11.Rh4 Ra3 12.Rh7 Be8 13.c3 Ra4
14.Ke3 (130.192.481) 638

22.01 5:41 +0.60 1.bxa6 Rxh4+ 2.Kc3 Rxa4 3.Rxa4 Bxa4
4.a7 Bc6 5.Kd4 Kd8 6.f4 Ba8 7.f5 Kc7
8.fxe6 fxe6 9.Bg6 Bc6 10.Bf7 Kd7
11.Bh5 Bb7 12.Bf3 Kc7 13.Bg4 Kd7
14.Bh3 (217.378.380) 635

23.01 19:36 +0.92++ 1.bxa6 Rxh4+ 2.Kc3 Rxa4 3.Rxa4 Bxa4
4.a7 Bc6 5.Kd4 Kd8 6.f4 Ba8 7.f5 Kc7
8.fxe6 (722.586.509) 614

24.01 25:03 +0.96 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Kb3 Ra1 10.Rh4 g5
11.Rh5 g4 12.Kb4 Ra2 13.Rh8 Kd7
14.Rh7 (927.439.476) 616

25.01 47:49 +1.01 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rg4 g6 8.Rf4 Ke7 9.Kb3 g5 10.Rg4 f6
11.exf6+ Kxf6 12.f3 d4 13.Rg3 Ra4
14.Be2 (1.682.115.673) 586

26.01 85:50 +0.96 1.bxa6 Rxh4+ 2.Kc3 Bc6 3.Rb1 Rxa4
4.Rxb6 Kd7 5.Rb4 Ra3+ 6.Kb2 Ra5
7.Rf4 f6 8.exf6 gxf6 9.Rxf6 Ke7
10.Rh6 Ra4 11.Kb3 Kd6 12.Rf6 Ke7
13.Rg6 Kd6 14.c4 (2.939.069.148) 570

26.02 194:06 +1.21 1.a5 Rxh4+ 2.Kc3 Bxb5 3.Bxb5 bxa5
4.Bxa6 Rf4 5.Rf1 f6 6.exf6+ gxf6
7.f3 e5 8.Be2 Kd6 9.Rb1 Kc6 10.Rb8 f5
11.Ra8 a4 12.Kb2 Kd6 13.Ra6+ Kc5
14.Ra5+ (6.445.630.237) 553

best move: a4-a5 time: 199:08.968 min n/s: 553.963 nodes: 6.619.290.206

Marc MP · Post by **Marc MP** » Thu Mar 11, 2010 5:54 am

After some more time running (Pro Deo 1.6):

Code: Select all

00:26:31.8	0,63	18	1553880673	a5 Rxh4+ Kc3 bxa5 bxa6 a4 a7 Rh8 

01:02:47.7	0,66	19	3623655011	a5 Bxb5 Bxb5 Rxh4+ Kc3 bxa5 Bxa6 Rf4 

01:10:24.8	0,66	20	4058082898	a5 Bxb5 Bxb5 Rxh4+ Kc3 bxa5 

02:58:39.0	0,85	21	1867271192	a5 Bxb5 Bxb5 Rxh4+ Kc3 bxa5 Bxa6 a4

Dann Corbit · Post by **Dann Corbit** » Fri Mar 12, 2010 2:58 am

It is not clear to me that a5 is better than bxa6.

Eelco de Groot · Post by **Eelco de Groot** » Fri Mar 12, 2010 3:12 am

Dann Corbit wrote:It is not clear to me that a5 is better than bxa6.

Well, Dann I said that because the leafpositions I got at the end of the bxa6 variations, just turned out to be draws, and in multi-PV, after a5, at least there was a drop in score for Black. I did not check everything but I'm sure at least that Michael Gurevich would have checked it is indeed winning, he checked everything for months. We can't access the old CSS forum to check the respective thread for this position anymore that's a pity. Each of these positions was first tested in the CSS forum by a battery of engines, I'm sure a draw would not have gotten through at least not without a5 still being a clearly better move than alternatives. The only question is in my opinion if there are more ways to win, in which case Michael may have chosen the move just because it's more clear, from a human point of view as that was the first selection criterion, only human GM games could qualify and he first analyzed it from a chessplayer's standpoint. But I think bxa6 just draws..

This was saved analysis with the older build 181:

[FEN "8/3bkpp1/pp2p3/1P1pP2r/P2K3P/3B4/2P2P2/R7 w - -"]

1. a5 Rxh4+ 2. Kc3 *

[d]8/3bkpp1/pp2p3/PP1pP3/7r/2KB4/2P2P2/R7 b - -

Engine: Rainbow Serpent 1.6.3s(dc) Build 181 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

21 8:51 -0.72 2...bxa5 3.bxa6 Bc6 4.a7 Rh8 5.Rxa5 Kd7
6.Kd4 Kc7 7.Kc5 Ra8 8.Ra1 g6 9.f4 Bb7
10.Bb5 Rh8 11.Ra3 Rc8 12.Rb3 Ba8 13.Bd3 Bb7
14.c4 Ra8 15.cxd5 Bxd5 (354.207.365) 666

21 8:51 -0.88 2...Bxb5 3.Bxb5 axb5 4.a6 b4+ 5.Kb3 Rh8
6.Kxb4 Kd7 7.Kb5 Kc7 8.Ra3 Kb8 9.Rc3 d4
10.Rc4 Rh1 11.Kxb6 Rb1+ 12.Kc5 Rb2 13.Kxd4 Rb6
14.Ra4 Ka7 15.Kd3 Rb8 (354.207.365) 666
_______________________________________________________________

22 18:48 -1.01 2...bxa5 3.bxa6 Bc6 4.a7 Rh8 5.Rxa5 Kd7
6.Kd4 Kc7 7.Kc5 Ra8 8.Be2 Bb7 9.Ra3 Bc6
10.Rf3 Rf8 11.Bb5 Ba8 12.Rf4 Bb7 13.c3 Ba8
14.Rg4 Rg8 15.Rg1 g5 (732.428.658) 648

22 18:48 -1.01 2...Bxb5 3.Bxb5 axb5 4.a6 b4+ 5.Kb3 Rh8
6.Kxb4 Kd7 7.Kb5 Kc7 8.Ra3 Kb8 9.Rg3 Rg8
10.Rc3 Rf8 11.Kxb6 f6 12.exf6 gxf6 13.Rc6 Re8
14.Rc7 f5 15.Rb7+ Ka8 (732.428.658) 648
_______________________________________________________________

23 46:53 -1.09 2...bxa5 3.bxa6 Bc6 4.Rxa5 Kd7 5.a7 Rh8
6.Kb4 Kc7 7.Kc5 Ra8 8.Be2 Bb7 9.Ra3 Bc6
10.Rf3 Rf8 11.Rg3 Rg8 12.Bb5 Bb7 13.Rg1 Ba8
14.f4 g6 15.Rh1 Kb7 (1.566.594.331) 556

23 46:53 -1.09 2...Bxb5 3.Bxb5 axb5 4.a6 b4+ 5.Kb3 Rh8
6.Kxb4 Kd7 7.Kb5 Kc7 8.Ra3 Kb8 9.Rg3 Rg8
10.Rc3 Rf8 11.f4 f6 12.Rg3 fxe5 13.fxe5 Rc8
14.Rxg7 Rxc2 15.Re7 Rb2+ (1.566.594.331) 556
_______________________________________________________________

24 84:51 -1.09 2...bxa5 3.bxa6 Bc6 4.Rxa5 Kd7 5.a7 Rh8
6.Kb4 Kc7 7.Kc5 Ra8 8.Be2 Bb7 9.Ra3 Bc6
10.Rf3 Rf8 11.Bb5 Bb7 12.Rg3 Rg8 13.Rg1 Ba8
14.Ba6 g6 15.Rg3 g5 (2.313.388.661) 454

24 84:51 -1.13 2...Bxb5 3.Bxb5 axb5 4.a6 b4+ 5.Kb3 Rh8
6.Kxb4 Kd7 7.Kb5 Kc7 8.Ra3 Kb8 9.Rg3 Rg8
10.Rc3 Rf8 11.f4 f6 12.Rg3 fxe5 13.fxe5 Rc8
14.Rxg7 Rxc2 15.Re7 Rb2+ (2.313.388.661) 454
_______________________________________________________________

25 301:56 -1.13 2...Bxb5 3.Bxb5 axb5 4.a6 b4+ 5.Kb3 Rh8
6.Kxb4 Kd7 7.Kb5 Kc7 8.Ra3 Kb8 9.Rg3 Rg8
10.Rc3 Rf8 11.f4 f6 12.Rg3 fxe5
13.fxe5 Rc8 14.Rxg7 Rxc2 15.Re7 Rb2+ (6.540.652.374) 361

25 301:56 -1.17 2...bxa5 3.bxa6 Bc6 4.Rxa5 Kd7 5.a7 Rh8
6.Kb4 Kc7 7.Kc5 Ra8 8.Be2 Bb7 9.Ra3 Bc6
10.Rf3 Rf8 11.Bb5 Bb7 12.Rg3 Rg8
13.Be2 Bc6 14.Ba6 Ba8 15.Rg4 Bc6 (6.540.652.374) 361

Marc MP · Post by **Marc MP** » Fri Mar 12, 2010 3:45 am

[d]8/5p2/r1k3p1/7p/2PK1P1P/1R4P1/8/8 w - - bm c5; hmvc 0; fmvc 1; id "GER - GER";

On this one Fritz 8 seems to do well with 5 mens Tbs:

Code: Select all


8/5p2/r1k3p1/7p/2PK1P1P/1R4P1/8/8 w - - 0 1

Analysis by Fritz 8:

1.Rb8 Ra1 2.Rc8+ Kb6 3.c5+ Kb7 4.Rf8 Kc6 5.Rxf7 Ra4+ 
  ±  (1.14)   Depth: 7/17   00:00:00  35kN

1.f5! 
  ±  (1.15)   Depth: 7/17   00:00:00  43kN

1.f5 Ra1 2.Rf3 Rd1+ 3.Rd3 Ra1 4.Ke5 Re1+ 5.Kf6 
  ±  (1.23)   Depth: 7/17   00:00:00  54kN

1.f5 Ra1 2.fxg6 fxg6 3.Rc3 Rd1+ 4.Ke5 Kc5 5.Kf6 Rd6+ 6.Kg5 
  ±  (1.08)   Depth: 8/19   00:00:00  84kN

1.Rb8! 
  ±  (1.09)   Depth: 8/19   00:00:00  98kN

1.Rb8 Ra3 2.Rf8 Ra7 3.Ke5 Kc5 4.Rc8+ 
  ±  (1.20)   Depth: 8/19   00:00:00  125kN

1.Re3! 
  ±  (1.20)   Depth: 8/19   00:00:00  140kN

1.Re3 Kd7 2.Kc5 f6 3.Kb5 Ra1 4.Rc3 Kc7 5.c5 
  ±  (1.23)   Depth: 8/19   00:00:00  165kN

1.Re3 Kd7 2.Re5 Ra3 3.Rg5 Ke6 4.c5 Kd7 5.Rd5+ Kc7 6.Rg5 
  ±  (1.25)   Depth: 9/18   00:00:00  255kN

1.Re3 Kd7 2.Re5 f6 3.Re3 Rd6+ 4.Ke4 Re6+ 5.Kf3 Rd6 6.c5 Rd1 
  ±  (1.23)   Depth: 10/20   00:00:00  393kN

1.Rb8! 
  ±  (1.23)   Depth: 10/21   00:00:00  480kN

1.Rb8 Kd7 2.Rb7+ Ke6 3.Rb5 Ra3 4.Rg5 Rb3 5.Re5+ Kd6 6.Re3 Rb1 
  ±  (1.28)   Depth: 10/24   00:00:01  803kN

1.Rb8 Kd7 2.c5 Kc6 3.Rc8+ 
  ±  (1.29)   Depth: 11/24   00:00:02  1828kN

1.f5! 
  ±  (1.29)   Depth: 11/24   00:00:02  2099kN

1.f5 gxf5 2.Rb5 Ra3 3.Rxf5 Rxg3 4.Rf6+ Kd7 5.Rxf7+ Ke6 6.Rf4 Rg2 7.Re4+ Kd6 8.Re8 Rg4+ 9.Re4 
  ±  (1.34)   Depth: 11/24   00:00:02  2223kN

1.f5 Ra2 2.Rf3 Rd2+ 3.Ke5 Rd6 4.Ra3 Rd2 5.Ra7 Re2+ 6.Kf6 gxf5 7.Kg5 Kc5 8.Rc7+ 
  ±  (1.32)   Depth: 12/29   00:00:03  3264kN

1.Re3! 
  ±  (1.32)   Depth: 12/29   00:00:04  3771kN

1.Re3 Kd7 2.Rd3 Kc6 3.Rf3 Ra5 
  ±  (1.26)   Depth: 13/26   00:00:06  5858kN

1.f5! 
  ±  (1.27)   Depth: 13/29   00:00:07  6322kN, tb=3

1.f5 Ra1 2.Rf3 Rd1+ 3.Ke5 Rd6 4.Ra3 Rd1 5.Rf3 
  ±  (1.32)   Depth: 13/30   00:00:09  8303kN, tb=16

1.Rb8! 
  ±  (1.32)   Depth: 13/30   00:00:10  9114kN, tb=16

1.Rb8 Ra7 2.Rg8 Kd6 3.f5 gxf5 4.Rg5 Ra3 5.Rxf5 Rxg3 
  ±  (1.40)   Depth: 14/31   00:00:18  16784kN, tb=29

1.Re3! 
  +-  (1.41)   Depth: 14/31   00:00:21  19437kN, tb=40

1.Re3 Ra7 2.Re5 Kd6 3.Rg5 Ra3 4.c5+ Kc6 5.f5 gxf5 6.Rxf5 Rxg3 
  +-  (1.42)   Depth: 14/31   00:00:23  21353kN, tb=41

1.Re3 Ra7 2.Re5 Kd6 3.f5 Ra1 4.Rd5+ Kc6 5.fxg6 fxg6 6.Rc5+ Kd7 7.Rg5 Ra6 8.c5 Kc7 9.Ke5 
  +-  (1.45)   Depth: 15/29   00:00:28  26676kN, tb=56

1.Re3 Ra7 2.Re5 Kd6 3.Rg5 Ra3 4.c5+ Ke6 5.Re5+ Kd7 6.Re3 Ra2 7.Ke5 
  +-  (1.45)   Depth: 16/36   00:00:45  41206kN, tb=151

1.f5! 
  +-  (1.46)   Depth: 16/47   00:00:56  51060kN, tb=344

1.f5 gxf5 2.Rb5 Ra3 3.Rxf5 Rxg3 4.Rf6+ Kd7 5.Rxf7+ Ke6 6.Rf4 Rg1 7.Re4+ Kd6 8.c5+ Kc7 9.Kd5 Rd1+ 10.Rd4 Rc1 
  +-  (1.49)   Depth: 16/48   00:01:09  62434kN, tb=497

1.f5 gxf5 2.Rb5 Ra3 3.Rxf5 Rxg3 4.Rf6+ Kd7 5.Rxf7+ Ke6 6.Rf4 Rg1 7.Re4+ Kd6 8.c5+ Kc6 9.Re6+ Kc7 10.Re5 Kc6 
  +-  (1.49)   Depth: 17/54   00:01:48  95847kN, tb=1524

1.Re3! 
  +-  (1.49)   Depth: 17/54   00:02:00  107mN, tb=1626

  +-  (1.65)   Depth: 17/54   00:02:37  141mN, tb=1741

1.c5! 
  +-  (1.65)   Depth: 17/60   00:03:16  177mN, tb=2233

1.c5! 
  +-  (1.81)   Depth: 17/60   00:03:31  192mN, tb=2442

1.c5 Kc7 2.Rb6 Ra4+ 3.Kd5 Ra3 4.Rf6 Rd3+ 5.Kc4 Rxg3 6.Rxf7+ Kc6 7.Rf6+ Kd7 8.Kd5 Rd3+ 9.Ke4 Rc3 
  +-  (1.81)   Depth: 17/60   00:03:51  211mN, tb=2527

1.c5! 
  +-  (2.09)   Depth: 18/52   00:04:30  249mN, tb=3659

1.c5 Ra4+ 2.Ke5 Kxc5 3.Kf6 Kc4 4.Rf3 Kd5 5.Kxf7 Ke4 6.Rc3 Ra6 7.Rc5 Kf3 8.Rg5 Rd6 9.Rxg6 
  +-  (2.16)   Depth: 19/55   00:07:08  392mN, tb=7197

1.c5 Ra4+ 2.Ke5 Kxc5 3.Kf6 Kc4 4.Rf3 Kd5 5.Kxf7 Ke4 6.Rc3 Ra6 7.Rc5 Kf3 8.Rg5 
  +-  (2.19)   Depth: 20/61   00:11:49  632mN, tb=13949

1.c5 Ra4+ 2.Ke5 Kxc5 3.Kf6 Kc4 4.Rf3 Kd5 5.Kxf7 Ke4 6.Rc3 Ra6 7.Rc5 Kf3 8.Rg5 Ke4 9.Rxg6 
  +-  (2.29)   Depth: 21/64   00:19:10  1034mN, tb=23072

(, Gold Industries 11.03.2010)

mgv77 the four hard ones

mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones

Re: mgv77 the four hard ones