## How long to find h4?

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David Dahlem
Posts: 900
Joined: Wed Mar 08, 2006 8:06 pm

### How long to find h4?

[D]5k2/1K1P1p2/5Pp1/pp1p4/3P4/4q2P/4P3/8 w - - 0 1

By forcing moves, i found a mate in 22, but not sure if it's correct. My machine is too slow too find a mate from this position. Perhaps someone with a faster machine could verify my line -

1.h4 Qe8 2.dxe8=Q+ Kxe8 3.h5 gxh5 4.Kc7 Kf8 5.e4 dxe4 6.d5 Kg8 7.d6 Kh7 8.d7 Kg6 9.d8=Q h4 10.Qe7 h3 11.Qxe4+ Kxf6 12.Kd6 h2 13.Qe5+ Kg6 14.Qxh2 Kf5 15.Qe5+ Kg4 16.Qf6 b4 17.Ke5 Kg3 18.Ke4 b3 19.Qf3+ Kh2 20.Qf2+ Kh1 21.Kf3 b2 22.Qg2# (Mate)

muxecoid
Posts: 150
Joined: Sat Jan 30, 2010 9:54 am
Location: Israel

### Re: How long to find h4?

Stockfish on my Q9550 needs 11 seconds to find it and give it +3.5.

At depth 25 score is +18 which means there is likealy a mate in a few more moves.

BTW engine disagrees disagrees with the second move of your line. For me it is 1. h4 Qe6 which gives one extra move.

Eelco de Groot
Posts: 4186
Joined: Sun Mar 12, 2006 1:40 am
Location: Groningen

### Re: How long to find h4?

My machine is not fast enough either to calculate a mate, but I'm glad that Rainbow Serpent can find h4, with a lot of luck involved and some tweaks. The branching factor was not so good so I had to break off the search before the 18th ply.

[D]5k2/1K1P1p2/5Pp1/pp1p4/3P4/4q2P/4P3/8 w - -

Engine: Rainbow Serpent 1.6.3s(dc) Build 151 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

1.00 0:00 -1.53 1.d8Q+ (211) 0

2.00 0:01 -0.72 1.d8Q+ Qe8 2.Qxd5 a4 3.Qd6+ Kg8
4.Qe7 (1.459.448) 812

3.01 0:01 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 Qxe2
4.Qxb5 (1.461.757) 813

4.01 0:01 +0.08 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 b4
4.Qxb4 Qxe2 5.Kb6 (1.482.951) 811

5.01 0:01 +0.08 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 b4
4.Qxb4 Qxe2 5.Kc5 (1.486.262) 813

6.01 0:01 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 Qe6+
4.Kc5 Qc8+ 5.Kb6 Qe6+ (1.530.931) 802

7.01 0:02 +0.08 1.d8Q+ Qe8 2.Qxa5 Kg8 3.e3 b4 4.Qxb4 Qxe3
5.Qe7 Qe4 6.Kc6 (1.656.994) 797

8.01 0:02 +0.20 1.d8Q+ Qe8 2.Qxa5 Kg8 3.e3 Kh7 4.Qb4 Qd7+
5.Kb6 Qe6+ 6.Kxb5 Qxe3 7.Qf8 (1.855.607) 786

9.01 0:03 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.e3 Kh7 4.Qb4 Qd7+
5.Kb6 Qe6+ 6.Kxb5 Qe8+ 7.Kc5 Qf8+
8.Kb5 Qe8+ (2.545.623) 775

10.01 0:04 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 Qb8+
4.Kc5 Qc8+ 5.Kb6 b4 6.Qxb4 Qb8+
7.Kc5 Qf8+ 8.Kb5 Qe8+ 9.Kb6 Qb8+ (3.553.175) 770

11.01 0:06 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 Qb8+
4.Kc5 Qc8+ 5.Kb6 b4 6.Qxb4 Qb8+
7.Kc5 Qf8+ 8.Kb5 Qe8+ 9.Kb6 Qb8+ (4.998.645) 780

12.01 0:09 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 Qb8+
4.Kc5 Qc8+ 5.Kb6 b4 6.Qxb4 Qb8+
7.Kc5 Qf8+ 8.Kb5 Qe8+ 9.Kb6 Qb8+ (7.636.091) 784

13.01 0:21 +0.20++ 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Kh7
4.Qb4 Qxe2 5.Qf8 (17.107.848) 800

14.01 0:34 +0.36 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Kh7
4.Qb4 Qe6 5.Qxb5 g5 6.Qd3+ Kh6 7.Qf3 Kg6
8.e3 Kh6 9.Kb7 Kg6 10.Kb8 Qd6+
11.Kc8 (28.676.932) 825

15.01 1:10 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Kh7
4.Qb4 Qe6 5.Qxb5 g5 6.Qd3+ Kh6 7.Qf3 Kg6
8.e3 Kh6 9.Kb7 Kg6 10.Kc7 (57.744.044) 816

15.05 2:38 +0.84++ 1.h4 Qe8 2.dxe8Q+ Kxe8 3.h5 Kf8 4.e4 dxe4
5.d5 e3 6.d6 Ke8 7.Kc7 (126.820.790) 799

16.01 3:55 +2.82++ 1.h4 Qe8 2.dxe8Q+ Kxe8 3.h5 Kf8 4.e4 dxe4
5.d5 e3 6.d6 Ke8 7.Kc7 (187.760.931) 797

17.01 5:41 +10.74++ 1.h4 Qe8 2.dxe8Q+ Kxe8 3.h5 Kf8 4.e4 dxe4
5.d5 e3 6.d6 Ke8 7.Kc7 (270.327.170) 792

best move: h3-h4 time: 91:33.421 min n/s: 788.420 nodes: 4.331.100.207

Eelco
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan

zullil
Posts: 5718
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

### Re: How long to find h4?

David Dahlem wrote:[D]5k2/1K1P1p2/5Pp1/pp1p4/3P4/4q2P/4P3/8 w - - 0 1

By forcing moves, i found a mate in 22, but not sure if it's correct.
Here's what Stockfish-1.6.3 (8 threads) gives through depth 35. No mate is declared. Note that the pv given at depth 35 is 57 half-moves long.

Code: Select all

``````Searching&#58; 5k2/1K1P1p2/5Pp1/pp1p4/3P4/4q2P/4P3/8 w - -
infinite&#58; 1 ponder&#58; 0 time&#58; 0 increment&#58; 0 moves to go&#58; 0
2     -1.70   00&#58;02      269 d8=Q+ Qe8 Qxa5 Qxe2
3     -0.36   00&#58;02      685 d8=Q+ Qe8 Qxa5 Qd7+ Kb6
4     -0.16   00&#58;02     1316 d8=Q+ Qe8 Qxa5 Kg8 Kb6 Qxe2 Qxb5
5     -0.04   00&#58;02     2059 d8=Q+ Qe8 Qxa5 Kg8 Kb6 b4 Qxb4 Qxe2
6     +0.00   00&#58;02     6604 d8=Q+ Qe8 Qxa5 Kg8 Kb6 Qe6+ Kxb5 Qxe2+ Kc6 Qc4+
Qc5 g5
7     +0.00   00&#58;02    11530 d8=Q+ Qe8 Qxa5 Kg8 Kb6 Qe6+ Kxb5 Qxe2+ Kc6 Qc4+
Qc5 g5 Kd6
8     +0.00   00&#58;02    25720 d8=Q+ Qe8 Qxa5 Kg8 Kb6 Qb8+ Kc5 Qc8+ Kb6 Qe6+
Kxb5 Qxe2+ Kc6 Qc4+ Qc5 g5 Kd6 Qa6+ Qc6 Qxc6+
Kxc6
9     +0.00   00&#58;02    51931 d8=Q+ Qe8 Qxa5 Kg8 Kb6 Qb8+ Kc5 Qc8+ Kd6 b4 Qa4
Qb7 Qe8+ Kh7 Qe3
10  >  +0.20   00&#58;02   201988 d8=Q+ Qe8 Qxa5 Kg8 Kc7 b4 Qxb4 Qxe2 Qe7
11     +0.20   00&#58;02   457412 d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe4 Kc6 g5 Qe7 Kg6
Qxe4+ dxe4 Kxb5 Kxf6
12     +0.40   00&#58;02   708980 d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe4 Kc6 Qe6+ Kc5
Qxe2 Kxd5 Qe6+ Kc5 Qxh3 d5 Qf5 Qxb5 Qxf6
13     +0.00   00&#58;02    1402k d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe4 Kc6 Qe6+ Kxb5
Qe8+ Kb6 Qb8+ Kc5 Qf8+ Kb5 Qe8+
14     +0.00   00&#58;02    2526k d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe4 Kc6 Qe6+ Kxb5
Qe8+ Kb6 Qb8+ Kc5 Qf8+ Kb5 Qe8+
15  >  +0.40   00&#58;02    3487k d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe4 Qe7 Qe6 Qxe6
fxe6 Kd6 g5 Ke7
16     +0.65   00&#58;03    5271k d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe6 Qxb5 g5 Qb1+
Kh6 Qb3 Kg6 Qf3 Kh6 Kb7 Kg6 e3 Qf5
17     +0.40   00&#58;03    8810k d8=Q+ Qe8 Qxa5 Kg8 Kc7 Kh7 Qb4 Qe6 Qxb5 g5 Qd7
Kg6 Qxe6 fxe6 Kc6 Kxf6 Kd6 Kf7 Ke5 Ke7 e3 Kf7 e4
dxe4 Kxe4 Kf6
18  >  +1.05   00&#58;04   15133k d8=Q+ Qe8 Qd6+ Kg8 Qe7 Qf8 e4 b4 exd5 b3 d6 b2
Qxf8+ Kxf8 d7 b1=Q+ Ka7 Qe4 d8=Q+ Qe8 Qd6+ Kg8 d5
Qe3+ Kb7
19     +1.17   00&#58;04   16971k d8=Q+ Qe8 Qd6+ Kg8 Qe7 Qf8 e4 b4 exd5 b3 d6 b2
Qxf8+ Kxf8 d7 b1=Q+ Ka7 Qe4 d8=Q+ Qe8 Qd6+ Kg8 d5
Qe3+ Kb7 Qb3+ Ka6 a4 Qd8+ Kh7 Qd7 Qd3+ Ka5 Qc3+
Kxa4 Qxf6 d6 Kg7 Qe7 Qd4+ Kb5 Qd3+ Kc5 Qxh3
20     +1.74   00&#58;05   26449k d8=Q+ Qe8 Qd6+ Kg8 Qe7 Qf8 e4 b4 exd5 b3 d6 b2
Qxf8+ Kxf8 d7 b1=Q+ Ka7 Qe4 d8=Q+ Qe8 Qd6+ Kg8 d5
Qe4 Qd8+ Kh7 Qxa5 Qd4+ Kb7 g5 Qb5 Kg6 Qc6 Qe5 Kc8
Qf5+ Kc7 Qe5+ d6 Kxf6 Kd8 Qa5+ Kc8 Qf5+ d7+ Ke7
Qc7 f6
20  >  +3.52   00&#58;06   30279k h4 Qe8 dxe8=R+ Kxe8 h5 Kf8 e4 b4 exd5 b3 d6 b2 d7
b1=Q+ Ka7 Qe1 d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kf8 h7
21    +10.42   00&#58;10   69252k h4 Qe8 dxe8=R+ Kxe8 h5 Kf8 e4 dxe4 d5 gxh5 Kc7
Kg8 d6 b4 d7 Kh7 d8=Q Kg6 Qe7 b3 Qxe4+ Kxf6 Qf3+
Kg5 Qg3+ Kf5 Qxb3 h4 Qxf7+ Kg4 Qe6+ Kg3 Qb3+ Kg4
Qc4+ Kg3 Qd3+ Kg4 Qe4+ Kg5 Qe5+ Kg4 Qxa5 h3 Qe5
Kf3
22    +11.43   00&#58;19  159368k h4 Qe8 dxe8=R+ Kxe8 h5 Kf8 e4 dxe4 d5 e3 d6 e2 d7
e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6 h8=Q Kf5
Kb6 b4 Kxa5 b3 Qh3+ Kxf6 Qxb3 Kg7 Qb7 Kf6 Qb5 Ke7
Qe5+ Kf8 Qf6 Kg8 Qe7 Kg7 Kb4 Kg8 Kc4 Kg7
23    +11.64   00&#58;22  192998k h4 Qe8 dxe8=R+ Kxe8 h5 Kf8 e4 dxe4 d5 e3 d6 e2 d7
e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6 h8=Q b4
Qd8 Kf5 Qxa5+ Kxf6 Qxb4 Kf5 Qb5+ Kf6 Qe8 g5 Qg8
Kf5 Qxf7+ Kg4 Qe6+ Kh4 Qe7 Kh5 Qh7+ Kg4 Qe4+ Kh5
Qd5 Kh4 Kc6 g4
24  > +13.05   00&#58;28  247582k h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q b4 Qd8 Kf5 Qxa5+ Kxf6 Qxb4 g5 Qe4 Kg7 Kc6 f6
Qe8 Kh6 Qf7 f5 Qxf5 Kh5 Qh3+ Kg6 Qd3+ Kh5 Qh7+
Kg4 Kd5 Kg3 Qc7+ Kh4 Qd7 g4
25  > +18.91   00&#58;40  371352k h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Ke5 Qd8 Kf5 Qe7 b4 Kc6 b3 Kd6 Kg5 Qe3+ Kf5
Qf3+ Kg5 Qd5+ Kf4 Qxb3 Kf5 Qd5+ Kg4 Qxa5 Kh3 Qa3+
Kg4 Qa4+ Kg5 Ke7 Kf5 Kxf7
26    +23.72   01&#58;13  710192k h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 Kg8
d6 Kh7 d7 gxh5 Kc7 h4 d8=Q Kg6 Kd6 Kf5 Ke7 Kf4
Kxf7 Ke3 Ke6 h3 Qxa5 b4 Qxb4 h2 Qc5+ Kf3 Qh5+ Kg3
Qe5+ Kf3 Qxh2 Ke3 f7 Kd3 Qd6+ Kc4 f8=Q
27  > +36.12   02&#58;15    1343M h4 Qxe2 h5 b4 d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 b3 Qd8 Kf4 Qxd5 g5 Qxb3 a4 Qxf7 Kg4
Kb7 Kf4 d5 Kf5 d6 Ke5 d7 a3 Qe7+ Kf5 d8=Q a2 Qd3+
Kg4
28    +25.90   03&#58;11    1904M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 a4 Kd6 a3 Qe8 Kg5 Qxb5+ Kh4 Qb4+ Kg5
Qc5+ Kf4 Qc4+ Kg5 Qxf7 Kh6 Qg7+ Kg5 f7 Kf5 Qe5+
Kg4 f8=Q Kh3 Qf3+ Kh4 Qxa3
29    +77.09   03&#58;53    2281M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 b4 Kd6 b3 Qe8 b2 Qb5+ Kg4 Qxb2 g5
Qb3 a4 Qxa4+ Kf5 Ke7 Kg6 Qc2+ Kh6 Kxf7 Kh5 Qh2+
Kg4 Qg2+ Kf5 Qxg5+ Kxg5 Ke7 Kg4 f7
30    +77.09   05&#58;05    2991M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 b4 Kd6 b3 Qe8 b2 Qb5+ Kg4 Qxb2 g5
Qb3 a4 Qxa4+ Kf5 Ke7 Kg6 Qc2+ Kh6 Kxf7 Kh5 Qh2+
Kg4 Qg2+ Kf5 Qxg5+ Kxg5 Ke7 Kg4 f7
31    +88.99   10&#58;02    5801M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 Ke6 Kxb5 g5 Kxa5 g4 Qc8+ Kxf6 Qxg4
Ke7 Qg5+ f6 Qe3+ Kf7 Qh3 Kg6 Qg4+ Kf7 Kb4 Kf8 Qd7
Kg8 Qe7 f5 Qg5+ Kh7 Qxf5+ Kh6 Kc4
32    +89.10   17&#58;21    9917M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 b4 Kd6 b3 Qe8 b2 Qb5+ Kg4 Qxb2 g5
Qb3 a4 Qxa4+ Kf5 Ke7 g4 Qxg4+ Kxg4 Kxf7 Kf5 Ke7
Kg5 f7 Kf5 f8=Q+ Ke5 Qg7+ Kf4 Qd4+ Kf3 Kf6
33    +89.15   27&#58;46   15670M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q Kf5 Kc6 b4 Kd6 b3 Qe8 b2 Qb5+ Kg4 Qxb2 g5
Qb3 a4 Qxa4+ Kf5 Ke7 g4 Qxg4+ Kxg4 Kxf7 Kf5 Ke7
Kg5 f7 Kf5 f8=Q+ Ke5 Qf6+ Ke4 Ke6 Kd3 Kf5
34    +89.20   48&#58;23   27345M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q a4 Qd8 Kf5 Qe7 a3 Qxf7 a2 Qxa2 Kxf6 Kc6 g5
Qf2+ Kg6 Kxb5 Kh5 Qd4 g4 Qf6 g3 Qf4 g2 Qh2+ Kg5
Qxg2+ Kf4 Qf2+ Ke4 Kc6 Kd3 Kd5 Kc3
35    +89.50 1&#58;20&#58;54   45591M h4 Qe6 d8=Q+ Qe8 Qxe8+ Kxe8 h5 Kf8 e4 dxe4 d5 e3
d6 e2 d7 e1=Q d8=Q+ Qe8 Qxe8+ Kxe8 h6 Kd7 h7 Ke6
h8=Q a4 Qe8+ Kxf6 Qxb5 a3 Qa6+ Kg5 Qxa3 f5 Qg3+
Kh6 Qe3+ Kg7 Kc8 Kf7 Qe5 f4 Qxf4+ Kg8 Qc4+ Kf8
Qc7 Kg8 Qe7 Kh8 Kd8 g5 Qxg5 Kh7 Ke7 Kh8 Kf6
Nodes&#58; 52947169338
Nodes/second&#58; 9341726
Best move&#58; h4
Ponder move&#58; Qe6
``````

metax
Posts: 344
Joined: Wed Sep 23, 2009 3:56 pm
Location: Germany

### Re: How long to find h4?

I do not get a really high score for 1.h4 here (also the low score for 1.d8Q is strange) but this may be due to the low depth. I stopped the search here because of the extremely high EBF.

Code: Select all

``````FEN&#58; 5k2/1K1P1p2/5Pp1/pp1p4/3P4/4q2P/4P3/8 w - - 0 1

ChessMind&#58;
1/14	00&#58;00	           0	0	-1,62	d7d8D+ De3e8 Dd8xa5 De8xe2
2/16	00&#58;00	       2.188	17.000	-1,25	d7d8D+ De3e8 Dd8xa5 De8xe2 Da5d8+ De2e8
3/17	00&#58;00	       5.207	36.000	-1,25	d7d8D+ De3e8 Dd8xa5 De8xe2 Da5d8+ De2e8 Dd8d6+
4/20	00&#58;00	      10.470	66.000	-1,45	d7d8D+ De3e8 Dd8xa5 De8xe2 Da5d8+ De2e8 Dd8d6+ Kf8g8
5/21	00&#58;00	      21.437	114.000	-1,29	d7d8D+ De3e8 Dd8xa5 De8xe2 Da5d8+ De2e8 Dd8d6+ Kf8g8 Dd6xd5
6/23	00&#58;00	      50.054	188.000	-1,45	d7d8D+ De3e8 Dd8xa5 De8xe2 Da5d8+ De2e8 Dd8d6+ Kf8g8 Dd6xd5 b5b4
7/26	00&#58;00	     209.769	292.000	-1,35	d7d8D+ De3e8 Dd8xa5 De8xe2 Da5d8+ De2e8 Dd8d6+ Kf8g8 Dd6xd5 b5b4 Kb7c7
8/31	00&#58;06	   2.247.813	354.000	-1,00	d7d8D+ De3e8 Dd8d6+ Kf8g8 Dd6e7 De8f8 Kb7a6 b5b4 Ka6xa5 b4b3 De7c7 Df8a3+
9/31	00&#58;07	   2.707.555	355.000	-1,22	d7d8D+ De3e8 Dd8d6+ Kf8g8 Dd6e7 De8f8 Kb7a6 b5b4 Ka6xa5 b4b3 De7b7 Df8a3+ Ka5b5
10/31	00&#58;10	   3.570.845	357.000	-1,14	d7d8D+ De3e8 Dd8d6+ Kf8g8 Dd6e7 De8f8 Kb7a6 b5b4 Ka6xa5 b4b3 De7b7 Df8a3+ Ka5b5 b3b2
11/37	00&#58;32	  11.499.741	354.000	-1,23	d7d8D+ De3e8 Dd8d6+ Kf8g8 Dd6e7 De8f8 Kb7a6 b5b4 Ka6xa5 b4b3 De7b7 Df8a3+ Ka5b5 b3b2 Kb5c6 Da3c3+
11/37+	00&#58;43	  15.147.367	351.000	-0,22	h3h4
11/37	00&#58;48	  16.879.962	350.000	+1,35	h3h4
12/41	02&#58;44	  58.605.289	356.000	+1,56	h3h4 De3e8 d7xe8D+ Kf8xe8 h4h5 Ke8f8 e2e4 b5b4 e4xd5 b4b3 d5d6 b3b2 d6d7 b2b1D+ Kb7a7 Kf8g8 d7d8D+ Kg8h7
``````

Eelco de Groot
Posts: 4186
Joined: Sun Mar 12, 2006 1:40 am
Location: Groningen

### Re: How long to find h4?

The result from Stockfish is very good, will be vey hard to improve I think. With 6 men EGTBs it would probably have seen a way to mate too, but that is not so very important. The win after h4 is pure tactics so I think that Luca's program just needs more depth if you want a higher score. Positional evaluation does not make much difference but it is easy to miss why h4 is good if you don't look deep. If the branching factor is not so good, or there is not much hash space it is easy to find h4 only very late. I got several versions that did not see h4 after 40 minutes if you spent too much time on d8Q+ as first move.

This was the best version:

[D]5k2/1K1P1p2/5Pp1/pp1p4/3P4/4q2P/4P3/8 w - -

Engine: Rainbow Serpent 1.6.3s(dc) Build 162 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

1.00 0:00 -1.53 1.d8Q+ (211) 0

2.00 0:00 -0.04 1.d8Q+ Qe8 2.Qxa5 Qxe2 3.Qd8+ Qe8
4.Qxd5 (8.480) 33

3.00 0:00 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kb6 Qxe2
4.Qxb5 (18.749) 70

4.00 0:00 -0.04 1.d8Q+ Qe8 2.Qxa5 Qxe2 3.Qd8+ Qe8
4.Qxd5 b4 5.Qd6+ Kg8 6.Qxb4 (43.428) 139

5.00 0:00 +0.08 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 b4
4.Qxb4 Qxe2 5.Qc5 (183.937) 357

6.00 0:00 +0.16 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 b4
4.Qxb4 Qxe2 5.Kd6 Qe6+ 6.Kc5 (218.798) 389

7.00 0:00 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Qb6 Qd7+
4.Ka6 Qc8+ 5.Ka5 Qc3+ 6.Kxb5 Qc4+
7.Ka5 Qa2+ 8.Kb4 Qc4+ 9.Ka5 (376.803) 492

8.00 0:01 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Qb6 Qd7+
4.Ka6 Qc8+ 5.Ka5 Qc3+ 6.Kxb5 Qc4+
7.Ka5 Qa2+ 8.Kb4 Qc4+ 9.Ka3 Qc3+
10.Ka4 Qc4+ 11.Ka5 (554.708) 538

9.01 0:02 -0.08 1.d8Q+ Qe8 2.Qxa5 Kg8 3.e3 g5 4.Qa3 Qd7+
5.Kb6 Qxh3 6.Kc5 Qg2 7.Kxb5 g4 (1.455.511) 633

10.01 0:03 0.00 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Kh7
4.Qa3 Qe6 5.Qe7 b4 6.Qxb4 Qxf6 7.Qc5 Qe6
8.h4 Kg7 (2.266.848) 671

11.01 0:05 +0.24++ 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Kh7
4.Qb4 Qxe2 5.Qf8 (3.722.819) 704

12.01 0:08 +0.64 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Qe4
4.Qxb5 Qf4+ 5.Kc8 Qxf6 6.Qxd5 Qa6+
7.Kd7 Qxe2 8.Qb3 Kg7 9.d5 Kf6 10.d6 (6.350.416) 731

13.01 0:20 +0.48 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Qe4
4.Qxb5 Qf4+ 5.Kc8 Qf5+ 6.Qd7 Qxf6
7.Qxd5 Qa6+ 8.Kd7 Qxe2 9.Qb3 Qa6
10.d5 Qa7+ 11.Kc6 Qa6+ 12.Qb6 Qc8+
13.Qc7 Qxh3 14.d6 (15.091.719) 742

14.01 0:39 +0.96++ 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Qe4
4.Qxb5 Qf4+ 5.Kc8 Qf5+ 6.Qd7 Qxf6
7.Qxd5 Qa6+ 8.Kd7 Qxe2 9.Qc6 Qe3
10.d5 Qxh3+ 11.Kc7 Qh2+ 12.d6 Kg7
13.Qe4 f5 14.Qe7+ (30.918.575) 779

15.01 0:46 +0.40 1.d8Q+ Qe8 2.Qxa5 Kg8 3.Kc7 Kh7
4.Qb4 Qe6 5.Qxb5 g5 6.Qd7 Kg6 7.Qxe6 fxe6
8.f7 Kxf7 9.Kd7 Kf6 10.Kd6 Kf7
11.Ke5 Ke7 12.e3 Kf7 13.e4 dxe4
14.Kxe4 (36.031.041) 781

15.08 1:03 +3.07++ 1.h4 Qxe2 2.h5 Kg8 3.d8Q+ Kh7 4.Qf8 (48.585.788) 766

16.01 1:59 +9.61 1.h4 Qe6 2.d8Q+ Qe8 3.Qxe8+ Kxe8
4.h5 Kf8 5.e4 dxe4 6.d5 gxh5 7.d6 Kg8
8.d7 Kh7 9.d8Q Kg6 10.Qxa5 Kxf6
11.Qxb5 Kg6 12.Qc6+ Kf5 13.Qd5+ Kf4
14.Qxf7+ (93.513.651) 784

17.01 3:15 +10.22 1.h4 Qe6 2.d8R+ Qe8 3.Rxe8+ Kxe8
4.h5 gxh5 5.Kc7 Kf8 6.e4 dxe4 7.d5 Kg8
8.d6 Kh7 9.d7 Kg6 10.d8Q e3 11.Qe7 b4
12.Qxe3 Kxf6 13.Qb6+ Kg5 14.Qxa5+ (151.359.330) 774

18.01 9:25 +12.00 1.h4 Qe6 2.d8Q+ Qe8 3.Qxe8+ Kxe8
4.h5 gxh5 5.Kc7 Kf8 6.e4 dxe4 7.d5 Kg8
8.d6 Kh7 9.d7 Kg6 10.d8Q e3 11.Qe7 h4
12.Qxe3 Kxf6 13.Qf4+ Kg6 14.Qg4+
(430.653.644) 761

19.01 20:19 +16.16++ 1.h4 Qe8 2.dxe8Q+ Kxe8 3.h5 gxh5
4.Kc7 Kf8 5.e4 dxe4 6.d5 Kg8 7.d6 Kh7
8.d7 Kg6 9.d8Q e3 10.Qe7 h4 11.Qxe3 Kxf6
12.Qf4+ Kg6 13.Qg4+ Kf6 14.Qxh4+
{[D]8/2K2p2/5k2/pp6/7Q/8/8/8 b - -
Starting with 14... Ke5, this is mate in 13 moves!}
(917.340.445) 752

20.01 103:24 +34.58++ 1.h4 (4.565.713.666) 735

best move: h3-h4 time: 105:57.265 min n/s: 737.065 nodes: 4.685.700.329
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan