Test position: Kasparov-Yussupov (1981)

[Albert Silver]

This is a classic position from young Kasparov (18) in his win over Yussupov in the 1981 USSR championship.

[d]2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31

The move is Ne4!

Strong engines on strong hardware should find it quite quickly, though not instantly.

[zullil]

This is a classic position from young Kasparov (18) in his win over Yussupov in the 1981 USSR championship.

[d]2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31

The move is Ne4!

Strong engines on strong hardware should find it quite quickly, though not instantly.

Almost instantly, at least for Critter:

Code: Select all

Critter v1.6a 64-bit, by Richard Vida
hardware POPCNT enabled
setboard 2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31
info string Opening book: "book.cbk" - 57853 entries [native]
info string GTB Init OK (5 piece set)
info string Using 8 thread(s), 2048 MB hash LP=off

    A   B   C   D   E   F   G   H
  +---+---+---+---+---+---+---+---+
8 |   |   | n | q |   |   | r | b |
  +---+---+---+---+---+---+---+---+
7 |   |   |   | p | r |   |   | k |
  +---+---+---+---+---+---+---+---+
6 |   | p | p |   | p |   |   | p |
  +---+---+---+---+---+---+---+---+
5 | p |   |   |   | P | p |   | B |
  +---+---+---+---+---+---+---+---+
4 |   |   |   | P |   | P |   |   |
  +---+---+---+---+---+---+---+---+
3 | P | P | N |   |   |   |   |   |
  +---+---+---+---+---+---+---+---+
2 |   |   |   |   |   | Q |   | P |
  +---+---+---+---+---+---+---+---+
1 | R |   |   |   |   |   | R | K |
  +---+---+---+---+---+---+---+---+
FEN: 2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31
Hashkey: a492f02c4e137ab9 mgpsq: +0.41
Pawnkey: c04f931cddc9cd1f egpsq: -0.05
Mtrlkey: 94453391

go infinite
 2/ 2  00:00     1148   1148K  +0.32 Rg3 Reg7
 3/ 4  00:00     1580   1580K  +0.07 Rg3 Reg7 Rc1 Rxg3 hxg3
 4/ 6  00:00     2276   1138K  +0.03 Rg3 Rxg3 hxg3 b5 Rc1 Rg7
 5/ 7  00:00     3986   1328K  -0.18 Rg3 Reg7 Rc1 Ne7 Kg1 Rxg3+ hxg3
 5/ 8  00:00     5878   1469K  -0.14 b4 Reg7 Rxg7+ Rxg7 Rg1 axb4 axb4 Rxg1+ Qxg1
 6/ 9  00:00     8777   1462K  -0.21 b4 Reg7 Rxg7+ Rxg7 bxa5 bxa5 Rg1 Nb6
 6/ 9  00:00     9335   1333K  -0.18 Rg3 Reg7 Rc1 Ne7 Kg1 Rxg3+ hxg3
 7/11  00:00    13869   1386K  -0.27 Rg3 Reg7 Rag1 Ne7 Qe2 b5 Kg2 Rxg3+ hxg3
 7/11  00:00    16750   1395K  -0.18 b4 Reg7 bxa5 bxa5 Rg3 Qe7 Kg1 Nb6
 8/14- 00:00    33855   1471K  -0.27 b4 Reg7 bxa5 bxa5 Rg3 Qe7 Kg1 Nb6
 8/14  00:00    38085   1464K  -0.35 b4 Reg7 Rg3 b5 Rag1 Ne7 Kg2 Rxg3+ hxg3 axb4 axb4
 8/14  00:00    39346   1513K  -0.27 Rg3 Reg7 Rag1 Ne7 Qe2 b5 Kg2 Rxg3+ hxg3
 9/16- 00:00    85949   1754K  -0.35 Rg3 Reg7 Rag1 Ne7 Qe2 b5 Kg2 Rxg3+ hxg3
 9/16  00:00    98225   1785K  -0.38 Rg3 Reg7 Rag1 Ne7 Rd1 b5 Kg2 Qb6 Qe2 a4
10/17  00:00   177574   1869K  -0.38 Rg3 Reg7 Rag1 Ne7 a4 Qf8 Qe2 Qa8 Bf3 Qc8 Bh5 Rxg3 hxg3 c5
11/20  00:00   269173   2039K  -0.38 Rg3 Reg7 Rag1 Ne7 a4 Qf8 Qe2 Qa8 Bf3 Qc8 Bh5 Rxg3 hxg3 c5
12/25- 00:00    1180K   3493K  -0.47 Rg3 Reg7 Rag1 Ne7 a4 Qf8 Qe2 Qa8 Bf3 Qc8 Bh5 Rxg3 hxg3 c5
12/25  00:00    1299K   3401K  -0.39 Rg3 Reg7 Rag1 Qf8 Ra1 Ne7 a4 Qa8 Rd1 Qb7 Kg1 Qc7 Kg2 Qb7 Kg1
13/25  00:00    1422K   3487K  -0.42 Rg3 Reg7 Rag1 Qf8 Ra1 Ne7 Qe3 b5 Qf2 Qa8 Kg1 Qb8 Rd1 Qb6 Rc1 Qb7 Qe3 Rxg3+ hxg3 b4 axb4 axb4
14/25  00:00    1958K   3886K  -0.45 Rg3 Reg7 Rag1 Qf8 Ra1 Ne7 Qe3 b5 Qf2 Qa8 Kg1 Qb8 Rc1 Qb6 Rd1 Rxg3+ hxg3 Bg7
15/33  00:01    8157K   6838K  -0.45 Rg3 Reg7 Qf3 Qe7 Rh3 Qf8 Rg3 Ne7 Qe3 b5 Qf2 Qa8 Kg1 Qb8 Rc1 Qb6 Rd1 Rxg3+ hxg3 Bg7
16/33  00:01   10070K   6790K  -0.46 Rg3 Reg7 Qf3 Qe7 Rh3 Qf8 Rg3 b5 Kg1 Ne7 Qd3 Qd8 Re1 Qb6 Rc1 Rxg3+ hxg3 Bg7 Bf7
16/33  00:01   11069K   6766K  -0.46 b4 Reg7 bxa5 bxa5 Na4 Nb6 Nc5 Qe7 Rxg7+ Rxg7 Rb1 Nd5 Rb7 Qf8 Qd2 a4
16/35+ 00:02   15615K   7239K  -0.36 Ne4 fxe4 f5 Qf8 f6 Reg7 Rxg7+ Rxg7 Qe1 Rg5 Qxe4+ Kg8 h4 Rg3 f7+ Kg7 Qf4 Rh3+ Kg1
16/43+ 00:02   17757K   7200K  -0.23 Ne4 fxe4 f5 Qf8 f6 Reg7 Rxg7+ Rxg7 Qe1 Rg5 Qxe4+ Kg8 h4 Rg3 f7+ Kg7 Qf4 Rh3+ Kg1
16/46+ 00:02   21275K   7253K  -0.04 Ne4 fxe4 f5 Qf8 f6 Reg7 Rxg7+ Rxg7 Qe1 Rg5 Qxe4+ Kg8 h4 Rg3 f7+ Kg7 Qf4 Rh3+ Kg1
16/46+ 00:03   26067K   7460K  +0.23 Ne4 fxe4 f5 Qf8 f6 Reg7 Rxg7+ Rxg7 Qe1 Rg5 Qxe4+ Kg8 h4 Rg3 f7+ Kg7 Qf4 Rh3+ Kg1
16/46  00:04   29873K   7354K  +0.30 Ne4 fxe4 f5 Qf8 f6 Bxf6 Qxf6 Reg7 Bg6+ Kh8 Raf1 Qxf6 exf6 Rxg6 Rxg6 Kh7 Rg2 Rxg2 Kxg2 Kg8 Kg3 Kf7 Kf4 Nd6 Ke5 Nf5 Kxe4 Kxf6 Rf2 h5 Rg2 Ne7 Rg1 Nd5 Kd3 b5 Rf1+ Ke7
17/46  00:04   33958K   7465K  +0.30 Ne4 fxe4 f5 Qf8 f6 Bxf6 Qxf6 Reg7 Bg6+ Kh8 Raf1 Qxf6 exf6 Rxg6 Rxg6 Kh7 Rg2 Rxg2 Kxg2 Kg8 Kg3 Kf7 Kf4 Nd6 Ke5 Nf5 Kxe4 Kxf6 Rf2 Kf7 Rg2 Nh4 Rg1 Nf5 Rg4 Ke7 Rg2 Kf6 Kd3 Kf7 Rg1 Ke7 Rg6 Kf7 Rg1
18/47  00:05   37914K   7558K  +0.30 Ne4 fxe4 f5 Qf8 f6 Bxf6 Qxf6 Reg7 Bg6+ Kh8 Raf1 Qxf6 exf6 Rxg6 Rxg6 Kh7 Rg2 Rxg2 Kxg2 Kg8 Kg3 Kf7 Kf4 Nd6 Ke5 Nf5 Kxe4 Kxf6 Rf2 Kf7 Rg2 Nh4 Rg1 Nf5 Rg4 Ke7 Rg2 Kf6 Kd3 Kf7 Rg1 Ke7 Rg6 Kf7 Rg1
19/47  00:07   59026K   8206K  +0.30 Ne4 fxe4 f5 Qf8 f6 Bxf6 Qxf6 Reg7 Bg6+ Kh8 Raf1 Qxf6 exf6 Rxg6 Rxg6 Kh7 Rg2 Rxg2 Kxg2 Kg8 Kg3 Kf7 Kf4 Nd6 Ke5 Nf5 Kxe4 Kxf6 Rf2 Kf7 Rg2 Nh4 Rg1 Nf5 Rg4 Ke7 Rg2 Kf6 Kd3 Kf7 Rg1 Ke7 Rg6 Kf7 Rg1
20/47  00:08   74962K   8518K  +0.30 Ne4 fxe4 f5 Qf8 f6 Bxf6 Qxf6 Reg7 Bg6+ Kh8 Raf1 Qxf6 exf6 Rxg6 Rxg6 Kh7 Rg2 Rxg2 Kxg2 Kg8 Kg3 Kf7 Kf4 Nd6 Ke5 Nf5 Kxe4 Kxf6 Rf2 d5+ Kd3 c5 dxc5 bxc5 Rg2 Nd4 Rf2+
21/49  00:13  126337K   9155K  +0.30 Ne4 fxe4 f5 Qf8 f6 Bxf6 Qxf6 Reg7 Bg6+ Kh8 Raf1 Qxf6 exf6 Rxg6 Rxg6 Kh7 Rg2 Rxg2 Kxg2 Kg8 Kg3 Kf7 Kf4 Nd6 Ke5 Nf5 Kxe4 Kxf6 Rg1 Kf7 Rg4 Ke7 Rg2 Nd6+ Ke5 Nf5 Ke4
?
bestmove Ne4 ponder fxe4

time: 18441 nodes: 174770679 evals: 129587285 knps: 9477
phash: 84.49% evalcache: 9.43% lazy: 48.33% eg_recog: 57694
splits: 75735
quit

[Ajedrecista]

Hello:

Analysis by Komodo 3 w32 (single core) in an Intel Pentium D930 (3 GHz), with 1 GB of hash, running under Arena 2.0.1 GUI:

FEN: 2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31

Komodo3-32:
1 00:01 157 5.024 +0,86 Qf2c2 b6b5
2 00:01 570 18.240 +0,78 Qf2c2 b6b5 Rg1g2
3 00:01 3.452 55.232 +0,59 Rg1g3 Re7g7 Ra1g1 Rg7xg3 Rg1xg3
4 00:01 7.262 77.461 +0,47 Rg1g2 Re7g7 Ra1g1 Rg7xg2 Rg1xg2
5 00:01 7.471 79.690 +0,31 Rg1g2 Re7g7
5 00:01 12.140 97.120 -0,16 Rg1g2 Rg8xg2
5 00:01 12.936 103.488 +0,18 Rg1g3 Rg8xg3 h2xg3 Re7g7 Kh1g1 Nc8e7 Ra1d1
5 00:01 15.400 98.560 +0,27 b3b4 Re7g7 b4xa5 b6xa5 Rg1xg7+ Rg8xg7 Ra1g1 Nc8b6
5 00:01 15.868 101.555 +0,27 b3b4 Re7g7 b4xa5 b6xa5 Rg1xg7+ Rg8xg7 Ra1g1 Nc8b6
6 00:01 17.332 110.924 +0,21 b3b4 Re7g7 b4xa5 b6xa5 Rg1xg7+ Rg8xg7 Ra1g1 Nc8b6 Rg1g3
6 00:01 21.095 122.734 +0,21 b3b4 Re7g7 b4xa5 b6xa5 Rg1xg7+ Rg8xg7 Ra1g1 Nc8b6 Rg1g3
7 00:01 22.714 121.141 +0,05 b3b4 Re7g7
7 00:01 41.218 155.173 -0,06 b3b4 Re7g7 b4xa5 b6xa5 Rg1xg7+ Rg8xg7 Ra1g1 Nc8e7 Rg1g2 Rg7xg2 Qf2xg2
7 00:01 43.104 153.258 +0,01 Rg1g3 Rg8xg3 h2xg3 Re7g7 Qf2e3 Nc8e7 Kh1g1 b6b5 Qe3d3
7 00:01 53.157 162.002 +0,01 Rg1g3 Rg8xg3 h2xg3 Re7g7 Qf2e3 Nc8e7 Kh1g1 b6b5 Qe3d3
8 00:01 55.376 161.093 0,00 Rg1g3 Rg8xg3 h2xg3 Re7g7 Qf2e3 b6b5 Kh1g1 Qd8g8 Kg1g2 Nc8e7
8 00:02 74.170 163.685 0,00 Rg1g3 Rg8xg3 h2xg3 Re7g7 Qf2e3 b6b5 Kh1g1 Qd8g8 Kg1g2 Nc8e7
9 00:02 92.881 169.839 -0,04 Rg1g3 Rg8xg3 h2xg3 Re7g7 Kh1g2 b6b5 Ra1h1 Qd8e7 Qf2b2 Rg7g8 Bh5f3 Qe7g7
9 00:02 143.475 183.648 -0,04 Rg1g3 Rg8xg3 h2xg3 Re7g7 Kh1g2 b6b5 Ra1h1 Qd8e7 Qf2b2 Rg7g8 Bh5f3 Qe7g7
10 00:03 246.218 181.125 -0,18 Rg1g3 Re7g7 Ra1g1 Qd8f8 Qf2a2 Rg7xg3 h2xg3 b6b5 Qa2b2 Nc8e7 Qb2c2 Ne7g6
10 00:03 400.134 189.693 -0,18 Rg1g3 Re7g7 Ra1g1 Qd8f8 Qf2a2 Rg7xg3 h2xg3 b6b5 Qa2b2 Nc8e7 Qb2c2 Ne7g6
11 00:04 480.860 189.969 -0,25 Rg1g3 Re7g7 Ra1g1 Qd8f8 Rg3xg7+ Rg8xg7 Rg1xg7+ Bh8xg7 Qf2g2 Kh7h8 Qg2g6 Nc8e7 Qg6g2 b6b5 Qg2g3
11 00:05 693.296 190.433 -0,14 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3d3 c6c5 d4d5 c5c4
11 00:05 788.881 192.703 -0,14 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3d3 c6c5 d4d5 c5c4
12 00:06 905.532 195.790 -0,23 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3f2 Qc8a6 Bh5e2 Qa6a8 Be2h5
12 00:07 1.192.504 194.199 -0,18 Qf2h4 Re7g7 Rg1xg7+ Bh8xg7 Qh4h3 Bg7h8 Bh5f7 Rg8g7 Qh3h5 Nc8e7 Ra1g1 Rg7xg1+ Kh1xg1 b6b5 a3a4 Qd8b6
12 00:07 1.233.632 195.426 -0,18 Qf2h4 Re7g7 Rg1xg7+ Bh8xg7 Qh4h3 Bg7h8 Bh5f7 Rg8g7 Qh3h5 Nc8e7 Ra1g1 Rg7xg1+ Kh1xg1 b6b5 a3a4 Qd8b6
13 00:08 1.403.154 196.933 -0,25 Qf2h4 Re7g7 Rg1xg7+ Bh8xg7 Qh4f2 Bg7h8 Ra1g1 Rg8xg1+ Qf2xg1 Nc8e7 Qg1g3 b6b5 Kh1g2 Bh8g7 Nc3e2 Qd8f8
13 00:09 1.493.004 198.653 -0,16 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3f2 Qc8a8 Qf2f3 Qa8a6 Rb1b8 Qa6a7
13 00:10 1.749.855 200.341 -0,16 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3f2 Qc8a8 Qf2f3 Qa8a6 Rb1b8 Qa6a7
14 00:11 1.957.748 202.416 -0,18 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3f2 Ne7d5 Nc3xd5 c6xd5 Rb1g1 Qc8c4 Qf2e3
14 00:12 2.341.099 207.234 -0,18 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3f2 Ne7d5 Nc3xd5 c6xd5 Rb1g1 Qc8c4 Qf2e3
15 00:14 2.704.714 208.556 -0,20 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3d3 c6c5 d4d5 c5c4 Qd3d4 Ne7g6 Rb1g1
15 00:17 3.463.416 212.316 -0,20 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 a3a4 Nc8e7 Qf2e3 Qf8c8 Qe3d3 c6c5 d4d5 c5c4 Qd3d4 Ne7g6 Rb1g1
16 00:21 4.171.137 211.531 -0,18 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Nc3a4 Ne7d5 Na4c5 a5a4 Rb1c1 Qg8f8 Rc1b1 Nd5c3 Rb1g1 Rg7xg1+ Qf2xg1 Qf8g7 Qg1g2 Qg7xg2+ Kh1xg2
16 00:24 4.965.781 214.302 -0,18 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Nc3a4 Ne7d5 Na4c5 a5a4 Rb1c1 Qg8f8 Rc1b1 Nd5c3 Rb1g1 Rg7xg1+ Qf2xg1 Qf8g7 Qg1g2 Qg7xg2+ Kh1xg2
17 00:31 6.328.492 214.980 -0,19 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Nc3a4 Ne7d5 Na4c5 a5a4 Rb1c1 Qg8f8 Rc1b1 Qf8c8 Rb1b7 Qc8d8 Bh5e2 Nd5c3 Be2d3 Qd8e8 Qf2d2
17 00:41 8.589.163 216.505 -0,19 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Nc3a4 Ne7d5 Na4c5 a5a4 Rb1c1 Qg8f8 Rc1b1 Qf8c8 Rb1b7 Qc8d8 Bh5e2 Nd5c3 Be2d3 Qd8e8 Qf2d2
18 00:51 10.867.095 217.070 -0,23 Rg1xg8 Qd8xg8 b3b4 a5xb4 a3xb4 Re7g7 Ra1a8 b6b5 Qf2e1 Qg8d8 Bh5f3 Qd8c7 Nc3e4 f5xe4 Bf3xe4+ Kh7g8 Qe1h4 Rg7f7 Be4g6 Rf7h7 f4f5 Rh7g7 Qh4xh6 Qc7b7
18 01:13 15.428.919 216.025 -0,03 Nc3e4
18 01:19 16.868.225 215.697 -0,04 Nc3e4 f5xe4
18 01:25 18.134.288 216.933 -0,05 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Rg1xg8 Kh7xg8 e5xf6 Re7g7 Qf2f4 Rg7g5 f6f7+ Kg8g7 Ra1g1 Rg5xg1+ Kh1xg1 Nc8e7 Qf4xe4 Qf8b8 Qe4f3 Ne7d5 Qf3g2+ Kg7h8 Qg2g6 Qb8f8 Kg1h1 Qf8g7 Qg6g3 Qg7f8 Qg3e5+ Kh8h7 Qe5g3 Kh7h8
18 01:25 18.186.714 217.073 -0,05 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Rg1xg8 Kh7xg8 e5xf6 Re7g7 Qf2f4 Rg7g5 f6f7+ Kg8g7 Ra1g1 Rg5xg1+ Kh1xg1 Nc8e7 Qf4xe4 Qf8b8 Qe4f3 Ne7d5 Qf3g2+ Kg7h8 Qg2g6 Qb8f8 Kg1h1 Qf8g7 Qg6g3 Qg7f8 Qg3e5+ Kh8h7 Qe5g3 Kh7h8
19 01:34 20.251.839 218.238 -0,05 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Rg1xg8 Kh7xg8 e5xf6 Re7g7 Qf2f4 Rg7g5 f6f7+ Kg8g7 Ra1g1 Rg5xg1+ Kh1xg1 Nc8e7 Qf4xe4 Qf8b8 Qe4f3 Ne7d5 Qf3g2+ Kg7h8 Qg2g6 Qb8f8 Kg1h1 Qf8g7 Qg6g3 Qg7f8 Qg3e5+ Kh8h7 Qe5g3 Kh7h8
19 01:39 21.495.350 218.991 -0,05 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Rg1xg8 Kh7xg8 e5xf6 Re7g7 Qf2f4 Rg7g5 f6f7+ Kg8g7 Ra1g1 Rg5xg1+ Kh1xg1 Nc8e7 Qf4xe4 Qf8b8 Qe4f3 Ne7d5 Qf3g2+ Kg7h8 Qg2g6 Qb8f8 Kg1h1 Qf8g7 Qg6g3 Qg7f8 Qg3e5+ Kh8h7 Qe5g3 Kh7h8
20 01:52 24.336.131 220.485 -0,05 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Rg1xg8 Kh7xg8 e5xf6 Re7g7 Qf2f4 Rg7g5 f6f7+ Kg8g7 Ra1g1 Rg5xg1+ Kh1xg1 Nc8e7 Qf4xe4 Qf8b8 Qe4f3 Ne7d5 Qf3g2+ Kg7h8 Qg2g6 Qb8f8 Kg1h1 Qf8g7 Qg6g3 Qg7f8 Qg3e5+ Kh8h7 Qe5e4+ Kh7h8 Qe4e5+
20 01:58 25.774.505 221.299 -0,05 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Rg1xg8 Kh7xg8 e5xf6 Re7g7 Qf2f4 Rg7g5 f6f7+ Kg8g7 Ra1g1 Rg5xg1+ Kh1xg1 Nc8e7 Qf4xe4 Qf8b8 Qe4f3 Ne7d5 Qf3g2+ Kg7h8 Qg2g6 Qb8f8 Kg1h1 Qf8g7 Qg6g3 Qg7f8 Qg3e5+ Kh8h7 Qe5e4+ Kh7h8 Qe4e5+
21 02:19 30.482.027 221.084 +0,11 Nc3e4
21 02:53 37.972.006 220.447 +0,27 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Rc1e1 h6h5 Kd3e4 c6c5 d4xc5 b6xc5 Ke4f4
21 02:59 39.282.585 220.999 +0,27 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Rc1e1 h6h5 Kd3e4 c6c5 d4xc5 b6xc5 Ke4f4
22 03:34 47.641.156 223.487 +0,27 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 b3b4 a5xb4 a3xb4 e6e5 d4xe5+ Kf6xe5 Rc1a1 Nf5d4 Ra1a6 Nd4f3 Ra6xb6 Nf3xh2 Rb6b7
22 03:40 49.059.481 223.999 +0,27 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 b3b4 a5xb4 a3xb4 e6e5 d4xe5+ Kf6xe5 Rc1a1 Nf5d4 Ra1a6 Nd4f3 Ra6xb6 Nf3xh2 Rb6b7
23 04:32 61.624.053 227.329 +0,17 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 b3b4 d7d5+ Ke4d3 a5xb4 a3xb4 e6e5 d4xe5+ Kf6xe5 Rf1c1 Ke5d6 Rc1g1 Kd6e5 Rg1g6 Nf5d6 Rg6xh6 c6c5 Rh6h5+ Nd6f5 b4xc5 b6xc5 Rh5g5
23 04:55 66.913.762 227.912 +0,17 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 b3b4 d7d5+ Ke4d3 a5xb4 a3xb4 e6e5 d4xe5+ Kf6xe5 Rf1c1 Ke5d6 Rc1g1 Kd6e5 Rg1g6 Nf5d6 Rg6xh6 c6c5 Rh6h5+ Nd6f5 b4xc5 b6xc5 Rh5g5
24 06:11 85.480.068 230.832 +0,16 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Ke4d3 e6e5 d4xe5+ Kf6xe5 Rf1e1+ Ke5d5 Kd3c3 d7d6 Re1e8 c6c5 a3a4 Nf5d4 Re8b8 Nd4e2+ Kc3d3 Ne2f4+ Kd3e3 Kd5e5 Rb8e8+ Nf4e6
24 07:32 103.045.090 228.425 +0,16 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Ke4d3 e6e5 d4xe5+ Kf6xe5 Rf1e1+ Ke5d5 Kd3c3 d7d6 Re1e8 c6c5 a3a4 Nf5d4 Re8b8 Nd4e2+ Kc3d3 Ne2f4+ Kd3e3 Kd5e5 Rb8e8+ Nf4e6
25 09:30 129.813.723 228.312 +0,16 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Ke4d3 e6e5 d4xe5+ Kf6xe5 Rf1e1+ Ke5d5 Kd3c3 d7d6 Re1e8 c6c5 a3a4 Nf5d4 Re8b8 Nd4e2+ Kc3d3 Ne2f4+ Kd3e3 Kd5e5 Rb8e8+ Nf4e6

I stopped the analysis after ten minutes. There is no problem for Komodo.

------------------------

Analysis by Spark 1.0 w32 (using two cores) in an Intel Pentium D930 (3 GHz), with 1 GB of hash, running under Arena 2.0.1 GUI:

FEN: 2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31

Spark-1.0-win32-mp:
1 00:00 3 0 +0,74 h2h4
1 00:00 9 0 +0,87 h2h3
1 00:00 15 0 +1,00 a3a4
1 00:00 66 0 +1,28 Qf2h4
2/1 00:00 166 0 +0,70 Qf2h4 Re7g7 Qh4xd8 Rg8xd8
2/2 00:00 273 0 +0,73 Rg1xg8 Kh7xg8
2/2 00:00 491 0 +0,85 Rg1g3 Re7g7
3/2 00:00 731 0 +0,52 Rg1g3 Re7g7 Ra1g1 Rg7xg3 Rg1xg3 Rg8xg3 h2xg3
3/2 00:00 847 0 +0,73 Rg1xg8 Kh7xg8 Qf2h4
4/4 00:00 2.667 0 +0,69 Rg1xg8 Qd8xg8 Ra1g1 Re7g7
4/5 00:00 3.104 0 +0,70 Qf2h4 Re7g7 Qh4xd8 Rg8xd8
5/5- 00:00 6.438 0 +0,45 Qf2h4 Re7g7 Qh4xd8 Rg8xd8
5/8 00:00 7.529 0 +0,53 Rg1xg8 Qd8xg8 Ra1g1 Re7g7 Rg1xg7+ Bh8xg7 Qf2g3
6/11 00:00 17.534 0 +0,36 Rg1xg8 Qd8xg8 Ra1g1 Re7g7 Rg1xg7+ Bh8xg7 Qf2g3 Nc8e7
6/11 00:00 20.504 0 +0,49 b3b4 Re7g7 Rg1xg7+ Rg8xg7 b4xa5 b6xa5 Ra1g1
7/11 00:00 38.107 0 +0,37 b3b4 Re7g7 Rg1xg7+ Rg8xg7 b4xa5 b6xa5 Ra1g1 Nc8b6
8/13 00:00 77.238 708.605 +0,13 b3b4 Re7g7 Rg1xg7+ Rg8xg7 b4xa5 b6xa5 Ra1g1 Rg7xg1+ Qf2xg1 Qd8g8 Qg1e1
8/13 00:00 95.466 681.900 +0,20 a3a4 Re7g7 Rg1xg7+ Rg8xg7 Ra1g1 Nc8e7 Rg1xg7+ Bh8xg7 Qf2g3 d7d6
8/13 00:00 131.666 704.096 +0,32 Rg1g3 Re7g7 Ra1g1 Rg7xg3 Rg1xg3 Nc8e7 a3a4 Rg8xg3 Qf2xg3
9/13 00:00 156.899 719.720 +0,30 Rg1g3 Re7g7 Ra1g1 Rg7xg3 Rg1xg3 Nc8e7 a3a4 Rg8xg3 Qf2xg3 Bh8g7
10/15 00:00 245.186 872.548 +0,20 Rg1g3 Re7g7 Ra1g1 Rg7xg3 Rg1xg3 Nc8e7 b3b4 Qd8a8 Rg3xg8 Qa8xg8 Qf2h4
11/20 00:00 466.034 995.799 +0,08 Rg1g3 Re7g7 Ra1g1 Rg7xg3 Rg1xg3 Nc8e7 Rg3xg8 Qd8xg8 Qf2h4 Qg8g7 a3a4 Ne7d5 Nc3xd5 c6xd5
11/20 00:00 658.270 1.028.546 +0,19 Rg1xg8 Qd8xg8 Qf2f3 Re7g7 Nc3e4 f5xe4 Qf3xe4+ Rg7g6 Ra1g1 Nc8e7 Bh5xg6+ Ne7xg6 f4f5 e6xf5 Qe4xf5 Qg8d5+ Rg1g2 Qd5e6
12/21 00:00 962.875 1.045.466 +0,19 Rg1xg8 Qd8xg8 Qf2f3 Re7g7 Nc3e4 f5xe4 Qf3xe4+ Rg7g6 Ra1g1 Nc8e7 Bh5xg6+ Ne7xg6 f4f5 e6xf5 Qe4xf5 Qg8d5+ Rg1g2 Qd5e6
13/27- 00:01 1.811.025 1.073.518 -0,06 Rg1xg8 Qd8xg8 Qf2f3 Re7g7 Nc3e4 f5xe4 Qf3xe4+ Rg7g6 Ra1g1 Nc8e7 Bh5xg6+ Ne7xg6 f4f5 e6xf5 Qe4xf5 Qg8d5+ Rg1g2 Qd5e6
13/27 00:02 2.405.413 1.012.805 -0,02 b3b4 Re7g7 Rg1xg7+ Rg8xg7 Ra1g1 Rg7xg1+ Kh1xg1 Nc8e7 Qf2h4 a5xb4 a3xb4 d7d6 Kg1h1 Bh8g7 Qh4g3 c6c5
14/27 00:04 5.231.090 1.059.568 0,00 b3b4 Re7g7 Rg1g3 Nc8e7 b4xa5 b6xa5 Ra1g1 Rg7xg3 Rg1xg3 Rg8xg3 Qf2xg3 Qd8b6 Qg3h4 Ne7d5 Qh4g3 Nd5e7
15/27 00:09 10.094.325 1.053.907 -0,13 b3b4 Re7g7 b4xa5 b6b5 Qf2e3 Nc8e7 a5a6 Qd8a8 Qe3d3 Rg7xg1+ Ra1xg1 c6c5+ Bh5f3 Rg8xg1+ Kh1xg1 Qa8xa6 Qd3xb5 Qa6xb5 Nc3xb5 c5c4
15/27 00:11 12.433.319 1.051.176 0,00 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 a3a4 Qg8a8 Rb1b2 Qa8g8 Rb2b1
16/30 00:14 15.830.167 1.098.859 0,00 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 a3a4 Qg8a8 Qf2f3 Qa8g8 Qf3h3 Qg8a8 Qh3f3
17/32 00:29 33.313.873 1.126.915 0,00 Rg1xg8 Qd8xg8 Qf2e3 Qg8d8 Ra1g1 Re7g7 Rg1g3 Qd8h4 Rg3h3 Qh4d8 Rh3g3
18/32 01:00 66.772.952 1.106.556 -0,11 Rg1xg8 Qd8xg8 Nc3a4 Re7g7 Ra1g1 Qg8f8 Qf2b2 Rg7xg1+ Kh1xg1 d7d6 Qb2g2 Qf8g8 Qg2xg8+ Kh7xg8 Bh5e8 b6b5 Be8d7 b5xa4 Bd7xc8 Kg8f7 b3xa4 d6xe5 d4xe5 c6c5
18/41+ 01:18 83.858.204 1.068.053 +0,25 Nc3e4 f5xe4
18/41+ 01:22 87.718.769 1.057.260 +0,50 Nc3e4 f5xe4
18/41 01:23 88.339.378 1.056.779 +0,46 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8d8 Rf1f4 Nc8d6 Qf6xd8 Rg8xd8 e5xd6 Rd8g8 Rf4g4 e4e3 Rg4g3 e3e2
19/41+ 01:37 102.791.408 1.056.133 +0,71 Nc3e4 f5xe4
19/41 01:41 107.853.113 1.059.502 +0,75 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g3 Nc8d6 Rf1g1 Rg8xg3 Rg1xg3 Kh7h8
20/41+ 02:06 132.093.203 1.046.805 +1,00 Nc3e4 f5xe4
20/41 02:08 135.473.772 1.051.333 +0,99 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Rg7xg6 Rg1xg6 Qf8xf6 Rg6xf6 Nc8e7 Ra1e1 h6h5 Re1xe4 Ne7d5 Rf6f7+ Rg8g7 Rf7xg7+ Kh7xg7 Re4e1 Kg7g6 Re1g1+ Kg6f5
21/41 02:44 174.174.972 1.061.233 +1,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Rg7xg6 Rg1xg6 Qf8xf6 Rg6xf6 Nc8e7 Ra1e1 Ne7d5 Rf6f7+ Rg8g7 Rf7xg7+ Kh7xg7 Re1xe4 Kg7g6 Re4g4+ Kg6f5 Rg4g7 Kf5e4 Rg7xd7 Ke4xd4
22/42 03:38 232.909.890 1.065.797 +1,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Rg7xg6 Rg1xg6 Qf8xf6 Rg6xf6 Nc8e7 Ra1e1 Ne7d5 Rf6f7+ Rg8g7 Rf7xg7+ Kh7xg7 Re1xe4 Kg7g6 Re4g4+ Kg6f5 Rg4g7 Kf5e4 Rg7xd7 Ke4xd4
23/54 05:23 346.407.581 1.070.917 +0,93 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Nc8d6 Rf1g1 Rg8xg2 Rg1xg2 Kh7h8 Rg2g7 e4e3 Kh1g2 Nd6e4 Rg7xd7 Ne4xf6 Rd7d6
24/58 08:50 565.325.165 1.066.369 +0,93 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Nc8d6 Rf1g1 Rg8xg2 Rg1xg2 Kh7h8 Rg2g7 e4e3 Kh1g2 Nd6e4 Rg7xd7 Ne4xf6 Rd7d6
24/58 10:00 652.354.331 1.086.239 +0,93 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Nc8d6 Rf1g1 Rg8xg2 Rg1xg2 Kh7h8 Rg2g7 e4e3 Kh1g2 Nd6e4 Rg7xd7 Ne4xf6 Rd7d6

I stopped the analysis after ten minutes. Spark could not miss this one.

------------------------

Analysis by Naum 4.2 w32 (using two cores) in an Intel Pentium D930 (3 GHz), with 1 GB of hash, running under Arena 2.0.1 GUI:

FEN: 2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31

Naum 4.2 x32:
1/7 00:02 107 6.687 +0,61 Qf2e3
2/9 00:02 749 46.812 +0,55 Ra1c1 d7d6
3/10 00:02 2.798 90.258 +0,30 Ra1e1 Re7g7 Rg1g3
4/11 00:02 6.424 207.225 +0,30 Rg1g3 Re7g7 Ra1e1 Rg7xg3
5/11 00:02 8.524 274.967 +0,11 Rg1g3 Re7g7 Bh5f3 Nc8e7 Ra1g1
6/16 00:02 13.233 281.553 +0,07 Rg1g3 Re7g7 b3b4 Nc8e7 b4xa5 Rg7xg3
6/17 00:02 17.210 366.170 +0,16 Rg1xg8 Kh7xg8 Qf2h4 Qd8f8 Bh5f3 Bh8g7
7/19 00:02 23.924 379.746 +0,09 Rg1xg8 Kh7xg8 Qf2h4 Qd8f8 Bh5f3 d7d5 b3b4
8/19 00:02 38.592 410.553 +0,12 Rg1xg8 Kh7xg8 Qf2h4 Qd8f8 Bh5f3 Re7f7 Ra1a2 Bh8g7
9/21 00:02 64.585 516.680 +0,08 Rg1xg8 Kh7xg8 Qf2h4 Qd8f8 Bh5f3 Re7f7 Ra1a2 Bh8g7 Kh1g1
10/23 00:02 120.011 638.356 +0,15 Rg1xg8 Kh7xg8 Qf2h4 Qd8f8 Bh5g6 Re7g7 Qh4xh6 Nc8e7 Bg6h5 c6c5
11/23 00:03 451.347 874.703 -0,10 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Bh5f3 Ne7d5 Nc3xd5
12/28 00:04 1.597.135 921.069 -0,17 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Bh5f3 Ne7g6 Bf3h5 Qg8d8
13/27 00:04 1.786.925 922.045 -0,16 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Nc3a4 Ne7d5 Na4c5 Qg8d8 Rb1b7
14/31 00:05 2.969.820 969.578 -0,16 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Ra1b1 Ne7d5 Na4c5 Qg8d8 Rb1b7 Kh7g8
15/33 00:13 11.388.316 1.019.362 -0,22 Rg1g3 Re7g7 Bh5f3 Nc8e7 Rg3h3 Ne7d5 Bf3xd5 c6xd5 Nc3b5 Qd8e7 Nb5d6 Rg7g6 Ra1c1 Bh8g7 Rc1c7
16/37 00:25 23.870.074 1.029.414 -0,27 Rg1g3 Re7g7 Rg3h3 b6b5 Bh5f3 Nc8b6 Qf2c2 Qd8e7 Nc3e4 Rg7g6 Ne4d6 Qe7g7 Qc2f2 a5a4 b3xa4 Nb6xa4
17/43 00:45 45.048.184 1.042.323 -0,25 Rg1g3 Re7g7 Rg3h3 b6b5 Bh5f3 Nc8b6 Qf2f1 Rg7f7 Bf3h5 Rf7f8 Bh5e2 Bh8g7 Rh3g3 b5b4 a3xb4 a5xb4 Nc3a4
18/39 01:04 66.584.382 1.069.353 -0,25 Rg1g3 Re7g7 Rg3h3 b6b5 Bh5f3 Nc8b6 Qf2f1 Rg7f7 Bf3h5 Rf7f8 Bh5e2 Bh8g7 Rh3g3 b5b4 a3xb4 a5xb4 Nc3a4 Nb6xa4
19/46 02:01 129.686.056 1.087.942 -0,28 Rg1g3 Re7g7 Rg3h3 b6b5 Bh5f3 Nc8b6 Nc3e4 Rg7g6 Ne4c5 Qd8e7 Bf3h5 Rg6g7 Bh5f3 Nb6d5 Bf3xd5 c6xd5 b3b4 a5a4 Ra1c1
19/49 02:57 191.575.507 1.098.640 -0,27 Nc3e4
19/60 04:33 298.717.121 1.104.633 +0,32 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2
20/57 05:48 387.075.008 1.118.765 +0,34 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8
21/60 07:46 525.662.610 1.133.428 +0,36 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3

I stopped the analysis after ten minutes. Good find by Naum!

------------------------

Analysis by Naum 4.2 w32 (using two cores) in an Intel Pentium D930 (3 GHz), with 1 GB of hash, running under Arena 2.0.1 GUI:

FEN: 2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 31

Stockfish-231-32-ja:
1/1 00:00 200 200.000 +1,61 Qf2f3 Rg8xg1+ Ra1xg1
2/3 00:00 769 769.000 +0,80 Qf2f3 Re7g7
3/4 00:00 1.578 1.578.000 +0,28 Qf2f3 Re7g7 Rg1g3 Rg7xg3 h2xg3
4/6 00:00 2.454 2.454.000 +0,24 Qf2f3 Re7g7 Rg1g3 Qd8h4
5/7 00:00 8.027 501.687 +0,04 Rg1xg8 Qd8xg8 b3b4 Re7g7 Qf2f3
6/7 00:00 10.366 647.875 +0,12 Rg1xg8 Qd8xg8 Bh5e2 d7d6 Ra1g1 Re7g7
7/11 00:00 16.842 526.312 +0,12 Rg1xg8 Qd8xg8 Bh5f3 Re7g7 Qf2h4 Qg8f8 Qh4h5 Nc8e7
8/13 00:00 32.015 508.174 0,00 Rg1xg8 Qd8xg8 Bh5f3 Re7g7 Qf2h4 Nc8e7 Qh4f6 Ne7g6 Nc3e2 Qg8f8
9/16 00:00 60.425 636.052 -0,12 Rg1xg8 Qd8xg8 Qf2e2 Re7g7 Qe2a6 Qg8d8 Ra1g1 Rg7xg1+ Kh1xg1 Nc8e7 Bh5f3 Bh8g7
10/16 00:00 190.813 717.342 -0,24 Rg1xg8 Qd8xg8 Nc3d1 Re7g7 Nd1e3 Nc8e7 Bh5e2 Qg8d8 Ra1c1 Kh7g8 Qf2h4
11/17 00:00 352.283 726.356 -0,36 Rg1xg8 Qd8xg8 Qf2f1 Re7g7 Qf1a6 Qg8d8 Bh5e2 Nc8e7 Be2h5 Ne7g6 Nc3e2 Qd8h4 Bh5xg6+ Rg7xg6 Qa6xb6
12/19 00:00 459.162 733.485 -0,32 Rg1xg8 Qd8xg8 Ra1g1 Re7g7 Rg1g3 Nc8e7 Kh1g2 b6b5 Qf2c2 Rg7xg3+ h2xg3 b5b4 a3xb4 a5xb4
13/19 00:00 562.839 719.742 -0,28 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 Rb1b3 Nc8e7 Rb3b7 Qf8c8 Rb7b1 Ne7d5 Nc3xd5 c6xd5
14/22 00:01 1.290.902 757.571 -0,36 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 Rb1b3 Nc8e7 Bh5e2 Ne7d5 Nc3xd5 c6xd5 a3a4 d7d6 Qf2h4 d6xe5 f4xe5
15/22 00:02 1.540.111 763.943 -0,36 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 Rb1b3 Nc8e7 Bh5e2 Ne7d5 Nc3xd5 c6xd5 a3a4 d7d6 Qf2h4 d6xe5 f4xe5
16/26- 00:02 2.132.379 775.128 -0,44 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 Rb1b3 Nc8e7 Bh5e2 Ne7d5 Nc3xd5 c6xd5 a3a4 Qf8c8 Rb3b5 Qc8c1+ Qf2f1 Qc1xf1+ Be2xf1 Rg7g4
16/26 00:03 2.510.607 779.691 -0,32 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 Rb1b3 Nc8e7 Bh5e2 d7d6 Rb3b6 Qf8d8 Rb6a6 d6xe5 f4xe5 Ne7d5 Ra6xc6 Nd5xc3 Rc6xc3 Qd8d5+ Be2f3
17/26 00:03 2.765.317 779.401 -0,32 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Qg8f8 Rb1b3 Nc8e7 Bh5e2 d7d6 Rb3b6 Qf8d8 Rb6a6 d6xe5 f4xe5 Ne7d5 Ra6xc6 Nd5xc3 Rc6xc3 Qd8d5+ Be2f3
18/26- 00:04 3.441.181 780.844 -0,40 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Qf2f3 Qg8f8 h2h3 Rg7g8 Rb1g1 Rg8xg1+ Kh1xg1 Qf8d8
18/26- 00:06 5.033.674 795.334 -0,48 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Qf2f3 Qg8f8 h2h3 Rg7g8 Rb1g1 Rg8xg1+ Kh1xg1 Qf8d8
18/37 00:08 7.047.556 806.818 -0,52 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Ra1b1 Nc8e7 Qf2f3 Qg8f8 Rb1b7 Qf8c8 Rb7b1 Qc8d8 Qf3h3 Qd8a8 Qh3f3 Qa8f8
19/37+ 00:10 8.408.113 800.696 -0,44 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Qe8h5 Rg1xg7+ Kh7xg7 Nc5xd7
19/37 00:11 8.934.187 801.919 -0,48 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Qe8h5 Rg1xg7+ Bh8xg7 Nc5xd7 Qh5d1+ Kh1g2 Qd1g4+ Qf2g3 Kh7g6
20/37+ 00:11 9.084.822 798.595 -0,40 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Qe8h5 Rg1xg7+ Bh8xg7 Nc5xd7 Qh5d1+ Kh1g2 Qd1g4+ Qf2g3 Kh7g6 Qg3xg4+ f5xg4 Nd7c5
20/37+ 00:11 9.269.299 796.263 -0,32 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Qe8h5 Rg1xg7+ Bh8xg7 Nc5xd7 Qh5d1+ Kh1g2 Qd1g4+ Qf2g3 Kh7g6 Qg3xg4+ f5xg4 Nd7c5
20/37+ 00:16 12.746.348 788.905 -0,20 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Re7g7 Rg1xg7+ Rg8xg7 Qf2h4 Rg7g5 Qh4xe4+ Kh7g8 h2h4 Rg5xh5 Qe4g6+ Bh8g7 Qg6xh5
20/37+ 00:16 13.390.545 789.816 -0,02 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 f6f7 Rg8f8 Rf1f6 Nc8e7 Rg6xh6+ Kh7g7
20/37+ 00:18 14.307.990 791.414 +0,25 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Rg8xg6 f6f7
20/37 00:18 14.721.244 792.359 -0,48 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Kh7g8 Qf2e3 Rg7g4 Qe3d2 Qe8d8 Rg1g3 Kg8f7
21/37+ 00:18 15.012.029 791.356 -0,40 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Kh7g8 Qf2e3 Rg7g4 Qe3d2 Qe8d8 Rg1xg4+ f5xg4 f4f5
21/37+ 00:19 15.190.210 790.333 -0,32 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Bh5f3 Ne7d5 Bf3xd5 c6xd5 Na4c5 Qg8e8 Ra1g1 Kh7g8 Qf2e3 Rg7g4 Qe3d2 Qe8d8 Rg1xg4+ f5xg4 f4f5
21/37 00:20 16.033.434 789.902 -0,36 Rg1xg8 Qd8xg8 b3b4 Re7g7 b4xa5 b6xa5 Nc3a4 Nc8e7 Na4c5 Ne7d5 Ra1b1 Qg8d8 Rb1b7 Kh7g8 Bh5e2 Qd8e8 Be2c4 Kg8h7 Bc4xd5 c6xd5 h2h4 Qe8h5 Rb7xd7 Rg7xd7 Nc5xd7
22/37- 00:25 20.215.303 793.690 -0,44 Rg1xg8 Qd8xg8 b3b4 a5xb4 a3xb4 Re7g7 b4b5 Nc8e7 b5xc6 d7xc6 Ra1a6 Qg8d8 Bh5f3 b6b5
22/37+ 00:34 27.384.280 790.516 -0,28 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Rg8xg6 f6f7 Rg6g8 f7f8Q Rg8xf8 Rf1xf8+ Kh8h7 Rf8xc8 e4e3 Kh1g2 e3e2 Kg2f2
22/37+ 00:36 28.653.344 791.441 -0,16 Nc3e4 f5xe4 f4f5 Rg8g5 Rg1xg5 h6xg5 f5f6 Re7e8 Qf2c2 Re8g8 Qc2xe4+ Kh7h6 Bh5f7 Qd8f8 Bf7xg8 Qf8xg8 Qe4g2 Qg8f8 Ra1g1
22/37+ 00:38 30.579.497 793.613 +0,02 Nc3e4 f5xe4 f4f5 Rg8g5 Rg1xg5 h6xg5 f5f6 Re7e8 Qf2c2 Re8g8 Qc2xe4+ Kh7h6 Bh5f7 Qd8f8 Bf7xg8 Qf8xg8 Qe4g2 Qg8f8 Ra1g1
22/43 00:43 34.365.972 798.317 +0,04 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 b3b4 a5xb4 a3xb4 d7d5+ Ke4d3 e6e5 d4xe5+ Kf6xe5 Rf1e1+ Ke5d6 Re1f1
23/43 00:46 36.820.350 800.964 +0,04 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 b3b4 a5xb4 a3xb4 d7d5+ Ke4d3 e6e5 d4xe5+ Kf6xe5 Rf1e1+ Ke5d6 Re1f1
24/46 00:53 43.106.687 805.717 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
25/46 01:03 51.399.584 811.833 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
26/46 01:14 60.991.287 820.216 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
27/46 01:29 73.831.623 827.096 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
28/46 01:49 91.394.367 834.050 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
29/46 02:20 117.828.691 839.289 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
30/46 03:11 161.543.121 844.736 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
31/46 04:07 208.795.330 842.443 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
32/46 05:43 289.510.859 842.095 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4
33/46 08:02 405.002.617 839.164 0,00 Nc3e4 f5xe4 f4f5 Qd8f8 f5f6 Bh8xf6 Qf2xf6 Re7g7 Bh5g6+ Kh7h8 Ra1f1 Qf8xf6 e5xf6 Rg7xg6 Rg1xg6 Kh8h7 Rg6g2 Rg8xg2 Kh1xg2 Kh7g8 Kg2g3 Kg8f7 Kg3f4 Nc8d6 Kf4e5 Nd6f5 Ke5xe4 Kf7xf6 Rf1c1 Nf5d6+ Ke4d3 Nd6f5 Kd3e4

I stopped the analysis after ten minutes. SF gives a 0.00 eval since depth 24 until depth 33!

Regards from Spain.

Ajedrecista.

[jdart]

My program likes Nd5, with the PV Nd5 Bxd5 Rxc5 Bxg2 Rc7 Bxh1 Rxe7 Nf6 fxe5 Nd5 Re6 dxe5 Qa1 e4 Re5 Nb4 Bxb4 axb4
Rb5 Rf7 Rxb4 Rd8 Rd4 Rfd7 Rxd7 Rxd7

--Jon

[zullil]

My program likes Nd5, with the PV Nd5 Bxd5 Rxc5 Bxg2 Rc7 Bxh1 Rxe7 Nf6 fxe5 Nd5 Re6 dxe5 Qa1 e4 Re5 Nb4 Bxb4 axb4
Rb5 Rf7 Rxb4 Rd8 Rd4 Rfd7 Rxd7 Rxd7

--Jon

What position did you have Arasan analyze?

[jdart]

What position did you have Arasan analyze?

I must have mangled it. This one is hard for Arasan: it does not see the draw. But with the right FEN it is not going crazy, either.

--Jon

[Robert Flesher]

My evil creation:(muahah) Dissident Aggressor settings for Zappa Mexico II. NO problem!

New game
2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - - 0 1

Analysis by Zappa Mexico II:

31.Ne4 fxe4 32.f5 Qf8 33.f6 Bxf6 34.Rxg8 Kxg8 35.exf6 Rg7 36.Qf4 Rg5 37.f7+ Kh7 38.Qxe4+ Kh8 39.Rg1 Nd6 40.Qf4 Rxg1+ 41.Kxg1 c5 42.dxc5 bxc5 43.Kf1 Nxf7 44.Qxf7 Qxf7+ 45.Bxf7 Kg7 46.Be8 d5 47.Ke2 Kf6 48.Bc6
+/- (0.86) Depth: 18 00:00:00 0kN
(Doe, 20.12.2012)

[Eelco de Groot]

Am I right to assume that, with the best defence Ne4 is a draw? The engines only give very low scores but that does not always say something because Albert's testmoves can be very difficult . Rainbow Serpent can find Kasparov's move only when in Multi PV. I get a good depth again in the normal search, I scaled down singular extensions, especially in the PV. I tried to make the Singular Extensions double a bit as Multi-CUT; if there is more than one move available to cross alpha (*), the Singular Extension can be turned into a Non-Singular Reduction According to Don Mullti-CUT should be almost as good a reduction as Nullmove in his tests in the past, so I thought it was worth a try... But for this position, I can't find Ne4 in normal search. It may be best because it threatens something, but I was wondering if any engine show something really good (Dissident Agressor is highest but the nodecounter is still zero there...)

Eelco

2nq2rb/3pr2k/1pp1p2p/p3Pp1B/3P1P2/PPN5/5Q1P/R5RK w - -

Engine: Rainbow Serpent Experimental Build 81 (2.3.2 + 8 builds) Q6700, 4 threads, 512 MB.
With Non-Singular Reductions introduced both in PV and non PV nodes, maximum one ply reduction.
by Tord Romstad, Marco Costalba and Joona Kiiski

17/30 0:01 +0.24++ 1.b4 Reg7 2.bxa5 bxa5 3.Rg3 Nb6
4.Rb1 Rxg3 5.hxg3 Nc4 6.Rb7 Bg7
7.Qh2 Qc8 8.Ra7 Bf8 (2.980.030) 2031

17/30 0:01 +0.12 1.b4 Reg7 2.Rg3 axb4 3.axb4 Qe7
4.Rb1 d5 5.b5 Rxg3 6.hxg3 c5 7.Ra1 Rg7
8.Ra8 Qb7 9.Ra6 cxd4 10.Ne2 (3.378.498) 2061

18/33 0:03 +0.20++ 1.Rxg8 Qxg8 2.Rg1 Rg7 3.Rxg7+ Qxg7
4.Qh4 Ne7 5.Be8 Qxe5 6.dxe5 d5
7.Qxe7+ Kg8 8.Nxd5 exd5 9.Bxc6 b5
10.Bxb5 d4 11.Qe8+ Kg7 12.Qxh8+ Kxh8
13.Bd7 Kg7 (7.694.238) 2172

18/33 0:03 +0.16 1.Rxg8 Qxg8 2.Rg1 Rg7 3.Rxg7+ Qxg7
4.Qh4 Qg8 5.a4 Qf8 6.Ne2 Ne7 7.Qg3 Qg7
8.Qxg7+ Bxg7 9.Be8 Nd5 10.Bxd7 Kg6
11.Bxe6 (7.786.205) 2169

19/33 0:03 +0.24++ 1.Rxg8 Qxg8 2.Qe2 Rg7 3.Ne4 fxe4
4.Qxe4+ Rg6 5.Rg1 Bxe5 6.Bxg6+ Qxg6
7.Rxg6 Bxf4 8.Qxf4 Kxg6 9.h3 Ne7
10.Qh2 (8.351.504) 2166

19/33 0:05 0.00 1.Rg3 Rxg3 2.hxg3 Rg7 3.Qh2 Kg8
4.Ra2 Qf8 5.Qh3 Qe7 6.Bf3 Qf8 7.Bh5 (12.250.293) 2218

20/33 0:05 0.00 1.Rg3 Rxg3 2.hxg3 Rg7 3.Qh2 Kg8
4.Ra2 Qf8 5.Qh3 Qe7 6.Bf3 Qf8 7.Bh5 (12.678.559) 2220

.
.
.
.

39/76 36:16 0.00 1.Rg3 Reg7 2.Rh3 d6 3.Bf3 Rg6 4.Bh5 R6g7 (4.997.115.156) 2295

40/76 45:08 0.00 1.Rg3 Reg7 2.Rh3 d6 3.Bf3 Rg6 4.Bh5 R6g7 (6.212.017.506) 2293

(*) Note to self, sorry : alpha can be pretty low in Rainbow Serpent in PV nodes, but this should be okay because a reduction is conservative in that case (big margin, and alpha in principle is used again when beta is exchanged for alpha in the sibling node) in the PV search.

[Eelco de Groot]

(*) Note to self, sorry : alpha can be pretty low in Rainbow Serpent in PV nodes, but this should be okay because a reduction is conservative in that case (big margin, and alpha in principle is used again when beta is exchanged for alpha in the sibling node) in the PV search.

This was a bit confusing, sorry again, edit: reduction is actually aggressive because with a low alpha, other moves can easily cross it. This is alpha before the first move is tried, the first move (first PV move) should in most cases raise alpha a lot.

This is the new code, it could be a bit more elegant by using a rAlpha instead of rBeta, for both PV and non PV nodes and just use > rAlpha instead of >= rBeta. I think it looks kinda cool that way because it is really compact then

Code: Select all

      // Singular extension search. If all moves but one fail low on a search of
      // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
      // is singular and should be extended. To verify this we do a reduced search
      // on all the other moves but the ttMove, if result is lower than ttValue minus
      // a margin then we extend ttMove.
      if (    singularExtensionNode // &&  ext < ONE_PLY
          &&  move == ttMove
          &&  pos.pl_move_is_legal(move, ci.pinned)
          &&  abs(ttValue) < VALUE_KNOWN_WIN)
      {
          Value rBeta = PvNode ? alpha : beta;
          ss->excludedMove = move;
          ss->skipNullMove = true;
          Value excValue = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth - 3* ONE_PLY);
          Move nextbestMove = ss->currentMove; // HACK
          assert(nextbestMove != ttMove);
          ss->skipNullMove = false;
          ss->excludedMove = MOVE_NONE;

          if (excValue < rBeta && nextbestMove != MOVE_NONE)
          {
              singularExtended = true;
              ext = ONE_PLY;
          }
          else if (excValue >= rBeta && !PvNode && nextbestMove != MOVE_NONE)
              ext -= ONE_PLY;
      }

Mmm, I see now, the reduction is not used in PV nodes , but maybe it could...

This code is also changed, to control the reduction

Code: Select all

singularExtensionNode =       !RootNode
                           && !SpNode
                           &&  depth >= SingularExtensionDepth[PvNode]
                           &&  ttMove != MOVE_NONE
                           && !excludedMove // Recursive singular search is not allowed
                           && (tte->type() & BOUND_LOWER)
                           &&  tte->depth() >= depth - 3 * ONE_PLY
                           && (PvNode ? (ttValue > alpha && ttValue < beta) : (ttValue >= beta && ttValue - futility_margin(depth, 0) <= beta));

Note that futility_margin(depth, 0) as far as I can see, is not negative in Rainbow Serpent's case. It is used a lot by now, I think it is 39 integer units but at least it is not supposed to be a negative number...

Eelco