The Arasan 8 unresolved positions:

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Dann Corbit, Harvey Williamson

jdart
Posts: 4359
Joined: Fri Mar 10, 2006 5:23 am
Location: http://www.arasanchess.org

Re: The Arasan 8 unresolved positions (Petrosian-Larsen)

Post by jdart »

"Petrosian-Larsen, Biel izt 1976" bm g5
result: g5 3600 seconds. score: +2.13 3968471762 nodes. ++ correct
g5 fxg5 fxg5 Rh3 Rd8+ Kc5 Rc8+ Kb6 Rb8 Rxh4 Rxb7+ Kxb7 Kg6 Ra4 Kxg7 Kc6 g6 Kd5 K
f7 Rf4+ Ke8 Ra4
result(2): Rb8 3600 seconds. score: +1.75 3648591796 nodes.
** error
Rb8 g6+ Kxg6 Rxg4+ Kxf6 Rxf4+ Kg5 Rxf8 Rxb7 Rg8+ Kf6 Rh8 Rb4 Kc5 Rg4 Kd6 Kg7 Rh5
Kg6 Re5 Rg5 Re6+ Kf7 Re4
result(3): Re6+ 3600 seconds. score: +1.69 3938607067 nodes.
** error
Re6+ Kd5 Rg8 Rd7 h5 Kd4 Re1 Kc3 h6 gxh6 Kxf6 Kd2 Ra1 Rd4 Ke5 Rgd3 Rh8 Ke3 Re1+

So g5 is best but this is less margin than I generally like to see for a test.
Top
jdart
Posts: 4359
Joined: Fri Mar 10, 2006 5:23 am
Location: http://www.arasanchess.org

Re: The Arasan 8 unresolved positions (Gulko-Saidy)

Post by jdart »

"Gulko-Saidy, American op Los Angeles 1987" bm Rxd5
result: Rxd5 3600 seconds. score: +1.44 2710951513 nodes. ++ correct
Rxd5 f5 exf6 cxd5 fxg7+ Qxg7 Bg6 bxa2 Bxh6 a1=Q Bxg7+ Kxg7 Qh7+ Kf6 Rxa1 Rxa1+ K
g2 d4+ Qxb7 Kxg6 Qe4+ Kf7 Qxd4 Ra7
result(2): axb3 3600 seconds. score: +1.28 2711368268 nodes.
** error
axb3 f5 exf6 Nxf6 Bxf6 Rxf6 f4 Kg8 Rd6 Qa5 Kf2 Qc3 Rd7 e5 Qg4 Qxc5+ Kf1 Rf7 Bh7+
Kxh7 Rxf7
result(3): Bxh6 3600 seconds. score: +0.75 2745766964 nodes.
** error
Bxh6 f5 Bxd5 cxd5 Be3+ Kg8 axb3 d4 Bxd4 f4 gxf4 Rxf4 Rd3 Qd8 Be3 Qxh4 Qxh4 Rxh4
Kf1 Rh2

Not much margin for Rxd5 above axb3.
Top
User avatar
Eelco de Groot
Posts: 4556
Joined: Sun Mar 12, 2006 2:40 am
Full name:   

Re: The Arasan 8 unresolved positions (Shredder-Rybka)

Post by Eelco de Groot »

jdart wrote:This one is valid but difficult:
"Shredder-Rybka, WCCC 2006" bm Bh6
result: Bh6 3600 seconds. score: +1.39 2511521532 nodes. ++ correct
Bh6 f5 Bxf8 Kxf8 Kh1 Kg8 Qe2 a5 Qd2 Qe7 b3 Qe6 g3 Qg6 Nh4 Qh5
result(2): Qf2 3600 seconds. score: +0.39 2325571123 nodes.
** error
Qf2 c4 Rae1 Bxe3 Qxe3 Re8 Qh6 Re6 Nd4 Rxe5 Rxe5 fxe5 Rxf7 Kxf7 Qxh7+
result(3): Rae1 3600 seconds. score: +0.50 2587701225 nodes.
** error
Rae1 Qe7 Bh6 Re8 Qc1 f5 Qf4 Qe6 Nh4 Kh8 Nxf5 c4+ Kh1 Qxf5 Qxf5 Bxf5 Rxf5 Rbe7

1000 seconds for Arasan to find this on a dual Xeon.


[D]3q1rk1/pr1b1p1p/1bp2p2/2ppP3/8/2P1BN2/PPQ3PP/R4RK1 w - -

Engine: Glaurung 2.0.1 Mjolnir 001b (256 MB, Athlon 2009 MHz)
by Tord Romstad

10.01 0:01 -0.52 1.Qf2 c4 2.Bxb6 Rxb6 3.Qg3+ Kh8
4.Rf2 Rg8 5.Qf4 c5 6.Kh1 Qe7 (596.274) 465

10.11 0:02 -0.31 1.Rae1 Bg4 2.exf6 Qxf6 3.Nd4 Qg6
4.Qxg6+ hxg6 5.Nxc6 Re8 6.b4 cxb4
7.Bxb6 Rxe1 8.Rxe1 Rxb6 9.Nxb4 (1.259.215) 575

11.01 0:02 -0.21 1.Rae1 f5 2.Qf2 c4 3.Qg3+ Kh8 4.Bxb6 Qxb6+
5.Rf2 c5 6.Rd1 Rg8 7.Ng5 (1.620.779) 603

12.01 0:03 -0.33 1.Rae1 f5 2.Qf2 c4 3.Qg3+ Kh8 4.Bxb6 axb6
5.Ng5 h6 6.Nf3 Rg8 7.Qf2 Ra7 (2.147.254) 627

13.01 0:08 -0.03 1.Rae1 Qe7 2.Qf2 Qe6 3.Qg3+ Qg4
4.Qxg4+ Bxg4 5.exf6 Re8 6.Bf4 c4+
7.Kh1 Rxe1 8.Rxe1 Be6 9.Ne5 Bc5 (5.773.443) 697

14.01 0:12 0.00 1.Rae1 Qe7 2.Qf2 Qe6 3.Qg3+ Qg4
4.Qxg4+ Bxg4 5.exf6 Re8 6.Bf2 Re4
7.Rxe4 dxe4 8.Ne5 Be6 9.Re1 Bd8 (9.252.578) 719

15.01 0:23 +0.07 1.Rae1 c4 2.exf6 Qxf6 3.Bxb6 axb6
4.Ne5 Qd6 5.Qf2 Qc5 6.Re3 f6 7.Rg3+ Kh8
8.Qxc5 bxc5 9.Nxd7 Rxd7 10.Kf2 Re8 (17.399.389) 743

16.01 0:42 +0.19 1.Rae1 c4 2.exf6 Qxf6 3.Bxb6 axb6
4.Ne5 Qd6 5.Rf3 f5 6.Qf2 Kh8 7.Qh4 Qf6
8.Qxf6+ Rxf6 9.Rg3 h6 10.Kf2 Kh7 (31.587.340) 752

17.01 1:35 +0.05 1.Rae1 fxe5 2.Nxe5 f6 3.Nxd7 Qxd7
4.Bh6 c4+ 5.Kh1 Re8 6.Qc1 Bd8 7.Rf3 Kh8
8.Rg3 Bc7 9.Rg7 Qd8 10.b4 Bf4 (73.021.689) 765

18.01 5:08 +0.25 1.Rae1 Qe7 2.Qf2 Qe6 3.Qg3+ Qg4
4.Qxg4+ Bxg4 5.exf6 Rc8 6.Ne5 Be6
7.Rf3 d4 8.Bf2 Ba5 9.Re2 dxc3
10.Rg3+ Kh8 11.bxc3 Rb1+ 12.Be1 (239.111.210) 776

18.02 12:08 +1.05 1.Bh6 f5 2.Bxf8 Kxf8 3.Kh1 Kg8
4.Rae1 Be6 5.Qa4 Bc7 6.Rf2 Rb5
7.Qxa7 Ra5 8.Qb7 Rxa2 9.Qxc6 Qe7 (564.979.341) 775

19.01 13:55 +1.11 1.Bh6 f5 2.Bxf8 Kxf8 3.Kh1 Bc7
4.Rae1 Rb8 5.g3 Rb5 6.Nh4 Qb8 7.Re2 Bxe5
8.Nxf5 f6 9.Kg1 Be6 10.Qd2 (647.473.948) 775

20.01 19:12 +1.27 1.Bh6 f5 2.Bxf8 Kxf8 3.Rae1 Kg8
4.Qd2 a5 5.Re2 d4 6.Qh6 Qf8 7.Qg5+ Qg7
8.Qxg7+ Kxg7 9.Rd1 dxc3 10.bxc3 Be6
11.Kf2 c4+ 12.Nd4 Bc5 13.Ke3 (881.205.772) 764


Eelco
Top
jdart
Posts: 4359
Joined: Fri Mar 10, 2006 5:23 am
Location: http://www.arasanchess.org

Re: The Arasan 8 unresolved positions (Petrosian-Larsen)

Post by jdart »

Shredder gives a pretty decisive score to g5:
no 9 250 +144 291571 Re6+ Kc5 Rc8+ Kd4 Rd8+ Kc5
no 9 310 +145 363919 Rb8
no 9 380 +156 436139 Rb8 Rd7 h5 Kc5 Rfc8+ Kd5 Re8 Kd4 Ke6 Rd5
no 10 500 +152 580841 Rb8 Rxb8 Rxb8 g6+ Kxg6 Rxg4+ Kf5 Rxh4
Rb6+ Kd5 Rxf6 Rh5+ Kg4 Rh7 Kf5
no 11 750 +152 870913 Rb8 Rxb8 Rxb8 g6+ Kxg6 Rxg4+ Kf5 Rxh4
Rb6+ Kd7 Ra6 Rh5+
no 11 970 +153 1124231 Re6+
no 11 1120 +153 1346002 Re6+ Kc5 Rc8+ Kd4 Rd8+ Kc5
no 12 2330 +152 2795456 Re6+ Kd5 Rd8+
no 13 4580 +152 5262963 Re6+ Kc5 Rc8+
no 14 7940 +153 9173081 Re6+ Kc5 Rc8+ Kd4 Rd8+ Kc5
yes 14 13280 +154 15432676 g5
yes 14 22020 +188 25942403 g5 fxg5 fxg5 Ra3
yes 15 38500 +213 44095519 g5 fxg5
yes 15 56660 +263 65939077 g5 fxg5
yes 15 86690 +293 98111336 g5 Rg1
yes 16 120910 +317 133635579 g5 fxg5 fxg5
yes 17 148750 +292 161380827 g5 fxg5
yes 17 164720 +292 177558917 g5 fxg5
yes 18 213470 +317 219556047 g5 fxg5
yes 18 355500 +367 357502807 g5 fxg5
yes 18 1066270 +437 1125264480 g5 Rg2
yes 19 1551780 +433 1661364841 g5 Rg1 Kg6 Kd5
Top

Return to “Computer Chess Club: General Topics”