Author: Hans Havermann
Date: 10:01:13 10/22/98
Go up one level in this thread
On October 20, 1998 at 20:17:00, Robert Hyatt wrote:
>I thought I would give this a whirl, since I have been making minor endgame
>scoring changes anyway, and was surprised to find this running Crafty 15.21
>on my 4 processor machine:
> 10 10.70 -1.17 1. ... Ke5 2. Rxb4 Rxa2+ 3. Kf3 Ra5
> 4. g4 Rc5 5. Re4+ Kd5 6. Rd4+ Ke5 7.
> g5 Rc1
> 10-> 17.04 -1.17 1. ... Ke5 2. Rxb4 Rxa2+ 3. Kf3 Ra5
> 4. g4 Rc5 5. Re4+ Kd5 6. Rd4+ Ke5 7.
> g5 Rc1
> 11 28.40 -1.30 1. ... Ke5 2. Kd3 Kd5 3. e4+ Ke5 4.
> Kc4 h6 5. Kxb4 Kxe4 6. a4 Rb8+ 7. Kc3
> Rd8
> 11 1:01 -1.26 1. ... Ra3 2. Rxb4 Rxa2+ 3. Kf3 Rc2
> 4. g3 Rc6 5. Ke4 Ke6 6. h4 h6 7. g4
> 11-> 1:23 -1.26 1. ... Ra3 2. Rxb4 Rxa2+ 3. Kf3 Rc2
> 4. g3 Rc6 5. Ke4 Ke6 6. h4 h6 7. g4
> 12 1:36 -1.32 1. ... Ra3 2. Rxb4 Rxa2+ 3. Kf3 Ra6
> 4. g4 h6 5. h4 Rd6 6. Rd4 Rc6 7. Ke4
> Ke6
> 12-> 2:19 -1.32 1. ... Ra3 2. Rxb4 Rxa2+ 3. Kf3 Ra6
> 4. g4 h6 5. h4 Rd6 6. Rd4 Rc6 7. Ke4
> Ke6
(Old) Crafty 14.6 (running on a G3) finds the ...Ra3 at 8-ply already:
8 -1.27 Ke5 Kd3 Kd5 e4+ Kc5 Rc2+ Kd6 Kc4 Rc8+ Kb3 Rb8
8 -1.09 Ra3 Kf3 Ke5 Rxb4 Rxa2 g4 h6 e4
8->-1.09 Ra3 Kf3 Ke5 Rxb4 Rxa2 g4 h6 e4
9 -1.11 Ra3 Kf3 Ra4 g4 Ke5 Rc2 h5 gxh5 gxh5 e4
9->-1.11 Ra3 Kf3 Ra4 g4 Ke5 Rc2 h5 gxh5 gxh5 e4
10 -1.11 Ra3 Rxb4 Rxa2+ Kf3 h5 g4 Kg5 gxh5 gxh5 Rb5+ Kh4 Ke4 Rd2
10->-1.11 Ra3 Rxb4 Rxa2+ Kf3 h5 g4 Kg5 gxh5 gxh5 Rb5+ Kh4 Ke4 Rd2
11 -1.12 Ra3 Rxb4 Rxa2+ Kf3 Ra3 Kf4 g5+ Ke4 h5 g4 hxg4 hxg4 Rc3 Rd4
11->-1.12 Ra3 Rxb4 Rxa2+ Kf3 Ra3 Kf4 g5+ Ke4 h5 g4 hxg4 hxg4 Rc3 Rd4
12 -1.11 Ra3 Rxb4 Rxa2+ Kf3 h5 Rb6+ Kg5 g3 Ra3 Rb5+ Kf6 Ke4 Ra4+ Kd5 Kf5 h4
12->-1.11 Ra3 Rxb4 Rxa2+ Kf3 h5 Rb6+ Kg5 g3 Ra3 Rb5+ Kf6 Ke4 Ra4+ Kd5 Kf5 h4
13 -1.14 Ra3 Rxb4 Rxa2+ Kf3 Ra5 g4 h5 h4 hxg4+ Rxg4 Ra3 Kf4 Ra1 e4 Rf1+ Ke3 Rd1
Rg5 Rd6
13->-1.14 Ra3 Rxb4 Rxa2+ Kf3 Ra5 g4 h5 h4 hxg4+ Rxg4 Ra3 Kf4 Ra1 e4 Rf1+ Ke3 Rd1
Rg5 Rd6
14 -1.13 Ra3 Rxb4 Rxa2+ Kf3 Ra5 Rb6+ Kg5 g3 Rf5+ Ke4 Rf1 Rd6 Rc1 Rd5+ Kf6 g4
Ke6 g5
14->-1.13 Ra3 Rxb4 Rxa2+ Kf3 Ra5 Rb6+ Kg5 g3 Rf5+ Ke4 Rf1 Rd6 Rc1 Rd5+ Kf6 g4
Ke6 g5
15 -1.17 Ra3 Rxb4 Rxa2+ Kf3 Ra6 h4 h6 Rb5 Ra3 g4 g5 Rf5+ Kg6 h5+ Kg7 Rd5
Kf6 Ke4
15->-1.17 Ra3 Rxb4 Rxa2+ Kf3 Ra6 h4 h6 Rb5 Ra3 g4 g5 Rf5+ Kg6 h5+ Kg7 Rd5
Kf6 Ke4
By contrast, MacChess (5.0b3) refuses to relinquish ...Ra4:
07/01| -125| Ke5 Rxb4 Rxa2+ Kf3 Rd2 Rb5+ Kf6 Rb6+ Ke5 e4
07/11| -124| Ra4 Kf3 h5 Re2 Ra3 g4 Rc3
08/01| -125| Ra4 Kf3 h5 g4 hxg4+ hxg4 Ke5 Re2 g5
09/01| -125| Ra4 Kf3 h5 g4 Ke5 Re2 Ra3 gxh5 gxh5 h4
10/01| -125| Ra4 Kf3 h5 g3 g5 g4 hxg4+ hxg4 Ke6 Re2 Kd5
11/01| -124| Ra4 g4 h5 gxh5 gxh5 Kf3 Ke5 h4 b3 Rxb3 Rxh4 Rb5+ Kd6 e4 Rh3+ Kf4
12/01| -123| Ra4 Kf3 h5 g3 g5 g4 h4 Rc2 Ke5 Rc5+ Kf6 Rc6+ Ke7 Rc4
13/01| -123| Ra4 Kf3 h5 g3 g5 g4 h4 Rc2 Ke5 Rc6 Ra7 Rc5+ Kf6 Rf5+ Kg6
14/01| -124| Ra4 h4 Ke5 Kf3 h6 Rb3 Kd6 g4 Ke5 Rb1 Kd6 Rb2 g5 h5
15/01| -124| Ra4 h4 Ke5 Kf3 h6 g4 h5 gxh5 gxh5 Rc2 Ra5 Re2 Ra3 Rg2 Kd6 Rf2
Never suggests ...Ra3: Subtle scoring differences, I suppose. With a losing
position such as this, I'm not sure it amounts to anything, anyhow.
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