Can white survive?
Posted: Thu Dec 06, 2012 3:04 am
In this post:
http://rybkaforum.net/cgi-bin/rybkaforu ... ?tid=26179
there seems to be the suggestion or implication that white should be able to at least draw the given position:
4r1k1/3n1p2/p4rp1/2pP3p/1qP5/RP2BBbP/3Q2P1/R5K1 w - -
It appears to me that white is in an inferior position. Does any analysis by other engines tend to prove otherwise?
In case you were wondering on the engine, the z designator is because I added a constructor to zero out some class/struct members for SplitPoint:
I was getting asserts fired because activePositions is uninitialized {which explains the letter z in the name}.
The ub stands for unitbuf. I added this code to main:
std::cout.setf(std::ios::unitbuf); // without this, communication is unreliable
std::cin.setf(std::ios::unitbuf); // without this, communication is unreliable
because the standard stockfish occasionally becomes disconnected from the GUI.
Hence, the designator -ub
The constructor change does not seem to affect the speed much, and the new version is fairing well in my current test:
http://rybkaforum.net/cgi-bin/rybkaforu ... ?tid=26179
there seems to be the suggestion or implication that white should be able to at least draw the given position:
4r1k1/3n1p2/p4rp1/2pP3p/1qP5/RP2BBbP/3Q2P1/R5K1 w - -
It appears to me that white is in an inferior position. Does any analysis by other engines tend to prove otherwise?
Code: Select all
Analysis of Q:\hur.epd
12/5/2012 5:37:35 PM Level: 1200 Seconds
Analyzing engine: Stockfish-231z-ub
1
Avoid move:
Best move (Stockfish-231z-ub): Qd2-c1
Not found in: 20:00
2/2 00:00 798 159,600 +1.65 Qxb4 cxb4
3/3 00:00 1,850 308,333 +1.65 Bg5 Qxd2 Bxd2
4/4 00:00 3,062 437,428 +1.53 Rxa6 Rxa6 Rxa6 Qxb3
5/5 00:00 9,551 1,061,222 +1.41 Bg5 Qxd2 Bxd2 Ne5 Be2 Bf2+ Kh1
6/7 00:00 10,663 1,066,300 +1.29 Bg5 Qxd2 Bxd2 Be5 Re1 Bd4+ Kh2
7/12 00:00 14,741 1,052,928 +1.37 Bg5 Qxd2 Bxd2 Be5 Re1 Bd4+ Kf1 Ne5
8/14 00:00 21,046 1,169,222 +1.33 Bg5 Qxd2 Bxd2 Be5 Re1 Bd4+ Kf1 Rxe1+ Kxe1 Rb6 g3
9/15 00:00 96,558 1,788,111 +1.09 R1a2 Ne5 Be2 Nd7 Bd1 Qb7 Bc2 Qc8 Ra5 Ne5 Bxc5
10/17 00:00 221,068 1,842,233 +0.76 Qc1 Ne5 Be2 Nd7 Bd3 Be5 Bd2 Bd4+ Kh1 Qb7 R1a2 Ne5
11/17 00:00 235,258 1,867,126 +0.76 Qc1 Ne5 Be2 Nd7 Bd3 Be5 Bd2 Bd4+ Kh1 Qb7 R1a2 Ne5
12/20 00:00 426,207 2,029,557 +0.96 R1a2 Qb8 Kh1 Rb6 Bd1 Qe5 Bg1 Qe1 Bf3 Qxd2 Rxd2 Kg7 Rda2 Re1 Rxa6 Rxb3
13/20 00:00 702,274 2,208,408 +0.88 Kh1 Ne5 Be2 Bf2 Bg5 Qxd2 Bxd2 Bd4 Re1 Rb6 Kh2 Reb8 Bf4 Rxb3 Rxa6 R8b4
14/20 00:00 775,470 2,228,362 +0.88 Kh1 Ne5 Be2 Bf2 Bg5 Qxd2 Bxd2 Bd4 Re1 Rb6 Kh2 Reb8 Bf4 Rxb3 Rxa6 R8b4
15/24 00:00 1,196,963 2,393,926 +0.80 Kh1 Ne5 Be2 Bf2 Bg5 Qxd2 Bxd2 Bd4 Re1 Rb8 Rf1 Rxf1+ Bxf1 f5 Be2 Kg7 Kh2 Rb6 Bg5 Nf7 Bf4 g5
16/28 00:01 2,637,595 2,528,854 +0.60 Kh1 Be5 R1a2 Bb2 Qxb4 cxb4 Ra5 Rxe3 Rxb2 Ne5 Be2 Rf2 Raa2 Rg3 Bd1 Rxb2 Rxb2 Rd3 Be2 Rc3 Kh2 Kf8
17/28 00:01 2,990,256 2,544,898 +0.60 Kh1 Be5 R1a2 Bb2 Qxb4 cxb4 Ra5 Rxe3 Rxb2 Ne5 Be2 Rf2 Raa2 Rg3 Bd1 Rxb2 Rxb2 Rd3 Be2 Rc3 Kh2 Kf8
18/28 00:01 4,202,726 2,570,474 +0.56 Kh1 Be5 R1a2 Bb2 Qxb4 cxb4 Ra5 Rxe3 Rxb2 Ne5 Be2 Rf2 Raa2 Rg3 Bd1 Rxb2 Rxb2 Rd3 Be2 Rc3 Kg1 Kf8 Kf2 Ke7 Ra2 Rxb3 Rxa6
19/28 00:01 4,666,349 2,596,744 +0.56 Kh1 Be5 R1a2 Bb2 Qxb4 cxb4 Ra5 Rxe3 Rxb2 Ne5 Be2 Rf2 Raa2 Rg3 Bd1 Rxb2 Rxb2 Rd3 Be2 Rc3 Kg1 Kf8 Kf2 Ke7 Ra2 Rxb3 Rxa6
20/38- 00:03 8,229,231 2,691,930 +0.10 Kh1 Be5 R1a2 Bc3 Qc1 Bb2 Qxb2 Rxe3 Rxa6 Rxb3 Qe2 Kg7 Be4 Qc3 Rxf6 Nxf6 Bc2 Rb4
20/49 00:05 14,451,599 2,743,800 0.00 Kh1 Be5 R1a2 Bc3 Qf2 Ne5 Bxc5 Nd3 Bxb4 Nxf2+ Rxf2 Re1+ Kh2 Bxb4 Raa2 Rb1 Kg3 Bd6+ Kh4 Rf4+ Kg5 Rf5+ Kh4 Rf4+ Kg5 Rf5+ Kh4 Rf4+
21/49 00:06 16,808,595 2,754,604 0.00 Kh1 Be5 R1a2 Bc3 Qf2 Ne5 Bxc5 Nd3 Bxb4 Nxf2+ Rxf2 Re1+ Kh2 Bxb4 Raa2 Rb1 Kg3 Bd6+ Kh4 Rf4+ Kg5 Rf5+ Kh4 Rf4+ Kg5 Rf5+ Kh4 Rf4+
22/49 00:10 27,631,117 2,764,770 0.00 Bh6 Be5 Qxb4 cxb4 Rxa6 Bd4+ Kh2 Be5+ Kg1 Bd4+ Kh2 Be5+ Kg1
23/49 00:12 35,795,766 2,770,784 0.00 Qc1 Be5 Bd2 Bd4+ Kh1 Qb8 Rb1 Qg3 b4 Be5 Qg1 Bd4 Qf1 Be5 Qg1 Bd4 Qf1 Be5 Qg1
24/49 00:14 40,332,758 2,770,677 0.00 Qc1 Be5 Bd2 Bd4+ Kh1 Qb8 Rb1 Qg3 b4 Be5 Qg1 Bd4 Qf1 Be5 Qg1 Bd4 Qf1 Be5 Qg1
25/49- 00:19 52,474,941 2,770,295 -0.08 Qc1 Be5 Bd2 Bd4+ Kh1 Qb8 Rb1 Ne5 Bf4 Qc8 Be2 Ng4 Bxg4 hxg4 b4 Qf5 Bg5 Rb6 hxg4 Qxg4 b5 Re2
25/49- 00:22 63,577,183 2,784,930 -0.16 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Qd2 Qc5+ Qf2 Re3 b4 Qd4 h4 Ne5
25/49- 00:30 84,535,149 2,772,098 -0.28 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Qg5 Qc3 Bxh5 Re5
25/49- 00:48 132,987,578 2,762,746 -0.46 Qc1 Be5 Rxa6 Bxa1 Rxa1 Qxb3 Ra3 Qb8 Bd1 Rb6 Bc2 Rb2 Bd2 Ne5 Bc3 Nf3+ gxf3 Qg3+
25/61 01:15 211,999,754 2,825,006 -0.40 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Rb6 Qd2 Ne5 Qxb4 Rxb4 Rd1 Rxb3 d6 Reb8 Kh2 Rc3 Be4 Rd8 Rxa6 Nxc4 Rxd3 Rxd3 Bxd3 Nxd6 Kg3 Kf8 Rc6 Ke7 Kf4 Ra8 Ke5
26/61- 01:26 244,228,440 2,831,568 -0.48 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Qb2 Rxf3 gxf3 Re2 Qa3 Qxa3 Rxa3
26/61- 01:34 266,470,173 2,834,517 -0.56 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Qd2 Qb8 h4 Rf4
26/61- 01:44 294,613,812 2,825,923 -0.68 Qc1 Be5 Ra4 Qb8 R1a3 Bd4 Bxd4 cxd4 Rxa6 Rxf3 gxf3 Qg3+ Kf1 Qxf3+ Kg1 Qg3+ Kf1 Qxh3+ Kg1 Re2
26/61 02:02 346,325,446 2,826,315 -0.64 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2 a5 Kg1 Rb6 Kh2 Reb8 Qe3 Na4 Rd2 Qd6+ Kg1 Nc5 Rdb2 f5 Qd4 Re8 Rf1 Rb7 h4 Qb6 Rd1
27/61+ 02:19 395,704,565 2,834,762 -0.56 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Qg3 Bf3 Be5 Kg1 Bd4+ Kh1
27/61+ 02:20 396,838,440 2,834,297 -0.48 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Qg3 Bf3 Be5 Kg1 Bd4+ Kh1
27/61+ 02:20 398,316,531 2,834,266 -0.36 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Qg3 Bf3 Be5 Kg1 Bd4+ Kh1
27/61 02:23 407,085,367 2,832,666 -0.40 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Be5 Qe1 Qd4 Qf1 f5 Bd1 Qe3 Ba4
28/61- 02:36 445,064,906 2,844,646 -0.48 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Be5 Qe1 Qd4 Qf1 f5 Bd1 Qe3 Ba4 Qg3
28/61 02:38 450,848,290 2,844,971 -0.48 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Be5 Qe1 Qd4 Qf1 f5 Bd1 Qe3 Ba4 Qg3 Kg1 Bd4+ Kh1
29/61- 02:57 505,356,188 2,847,333 -0.56 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7
29/61- 03:08 537,506,483 2,852,068 -0.64 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1
29/61- 03:40 631,273,181 2,861,982 -0.76 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Rd6 Ne5 Bxc5 Nxc4
29/61 03:48 653,589,326 2,863,191 -0.56 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Be5 Qe1 Qd4 Qc1 f5 Bf3 Kf7 Be2 Qe4 Bf3 Qd3 Qe1 Qd4
30/61- 04:13 727,269,145 2,866,932 -0.64 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Be5 Qe1 Qd4 Qc1 f5 Bf3 Kf7 Be2 Qf2 Qf1 Qg3
30/61- 04:29 773,527,607 2,870,605 -0.72 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Ra7 Bf6 Rxd7 Rxe3 Rb7 Qxb7 Qxe3 Qb1+ Qg1 Qd3 Qc1 Kg7 Bg4 Be5 Qe1 Qd4 Qc1 f5 Bf3 Kf7 Be2 Bd6
30/61- 05:38 974,569,114 2,876,209 -0.84 Kh1 Be5 Ra4 Qxd2 Bxd2 Bxa1 Rxa1 Rb6 Rb1 Ne5 Ba5 Rb7 Be2 Reb8
30/61- 08:39 1,500,728,028 2,890,634 -1.03 Kh1 Be5 R1a2 Bc3 Qf2 h4 Rxa6 Rxa6 Rxa6 Qxb3 Qg1 Qxc4 Ra7 Qd3 Bf2 Ne5 Qd1 c4 Qxd3 cxd3
30/63 11:59 2,091,489,193 2,905,725 -1.01 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2 a5 Kg1 Rb6 Kh2 h4 Qf4 Qc3 Rf2 Rf6 Qd2 Qd4 Qb2 Nxb3 Qxd4 Nxd4 Rd1 Rc8 Rxd3 Rxc4 Ra2 a4 Bd1 Rd6 Rxa4 Rxa4 Bxa4 Rxd5 Bb3 Rd6
31/63+ 12:13 2,132,036,218 2,906,059 -0.92 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2 a5 Kg1 Rb6 Kh2 h4 Qf4 Qc3 d6 Ne6 Qxh4 Rxd6 Bd5
31/63 13:12 2,304,866,747 2,907,380 -1.01 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2 a5 Kg1 Rb6 Kh2 h4 Qf4 Qc3 Rf2 Rf6 Qd2 Qd4 Qb2 Nxb3 Qxd4 Nxd4 Rd1 Rc8 Rxd3 Rxc4 Ra2 a4 Bd1 Rd6 Rxa4 Rxa4 Bxa4 Rxd5 Bb3 Rd6
32/63+ 13:54 2,428,050,169 2,909,830 -0.92 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2
32/63+ 14:15 2,481,697,167 2,899,473 -0.84 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2 a5 Kg1 Rb6 Kh2 h4 Qf4 Qc3 d6 Ne6 Qxh4 Rxd6
32/63 15:26 2,673,548,507 2,885,714 -1.01 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Rab2 a5 Kg1 Rb6 Kh2 h4 Qf4 Qc3 Rf2 Rf6 Qd2 Qd4 Qb2 Nxb3 Qxd4 Nxd4 Rd1 Rc8 Rxd3 Rxc4 Ra2 a4 Bd1 Rd6 Rxa4 Rxa4 Bxa4 Rxd5
33/63+ 16:48 2,908,446,975 2,883,510 -0.92 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Qd2
33/63+ 17:00 2,942,445,647 2,882,585 -0.84 Qc1 Be5 Rb1 Bd4 Bxd4 cxd4 Ra2 d3 Kh1 Nc5 Qd2
12/5/2012 5:57:38 PM, Time for this analysis: 00:20:00, Rated time: 20:00
0 of 1 matching moves
12/5/2012 5:57:39 PM, Total time: 12:20:03 AM
Rated time: 20:00 = 1200 Seconds
Code: Select all
SplitPoint()
{
pos = 0;
master = 0;
mp = 0;
parent = 0;
memset(activePositions, 0, sizeof activePositions);
}
The ub stands for unitbuf. I added this code to main:
std::cout.setf(std::ios::unitbuf); // without this, communication is unreliable
std::cin.setf(std::ios::unitbuf); // without this, communication is unreliable
because the standard stockfish occasionally becomes disconnected from the GUI.
Hence, the designator -ub
The constructor change does not seem to affect the speed much, and the new version is fairing well in my current test:
Code: Select all
Program Elo + - Games Score Av.Op. Draws
1 Stockfish-231z-ub : 2858 85 47 21 59.5 % 2791 81.0 %
2 Stockfish 121204Qi x64 : 2815 72 68 22 52.3 % 2799 77.3 %
3 Stockfish 121204Q x64 SSE4.2 : 2811 91 90 23 52.2 % 2796 60.9 %
4 Stockfish-231x-ub : 2789 68 72 22 47.7 % 2805 77.3 %
5 Stockfish 121204Q x64 : 2787 79 81 23 47.8 % 2802 69.6 %
6 Stockfish-231y-ub : 2784 51 62 21 47.6 % 2800 85.7 %
7 Stockfish 121204Qi x64 SSE4.2 : 2758 79 86 22 43.2 % 2806 68.2 %