Author: Kolss
Date: 07:12:45 07/25/02
Go up one level in this thread
On July 24, 2002 at 23:34:17, Slater Wold wrote:
>[D]1N4br/3pkPp1/6PP/8/pp3P2/8/P4r1P/6K1 w - - 0 1'
>
>Every program I tested found the correct move in about 5 seconds.
>
>Every program I tested then failed low for 10-13 ply.
>
>The real test here is not "finding" the move. But finding that it's winning.
>
>How long does it take your program to find hxg7, and _know_ it's winning?
Fantastic position! (Thanks for posting it!)
Here is what Ikarus thinks about it (K6/2-475MHz, 8MB Hash):
9 0 +4.28 1. hxg7 Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Nxd7 Kxg7 6. f5
10 2 +4.22 1. hxg7 Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Na6 Kxg7 6. Nxb4 Kf6
11 3 FailLow 1. hxg7? Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Na6 b3 6. axb3 axb3
11 4 +3.74 1. hxg7 Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Nxd7 b3 6. axb3 axb3 7. Ne5+ Kxg7
12 14 +3.72 1. hxg7 Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Nxd7 b3 6. g8=Q+ Kxg8 7. Nf6+ Kf7
13 26 +3.59 1. hxg7 Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Nxd7 b3 6. g8=Q+ Kxg8 7. axb3 axb3 8. Nf6+ Kf7 9. Nd5
14 51 FailLow 1. hxg7? Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Nxd7 b3 6. axb3 a3 7. g8=Q+ Kxg8 8. Nc5 a2
14 52 FailLow 1. hxg7? Rg2+ 2. Kxg2 Rxh2+ 3. Kxh2 Bxf7 4. gxf7 Kxf7 5.
Nxd7 b3 6. axb3 a3 7. g8=Q+ Kxg8 8. Nc5 a2
14 83 +0.44 1. hxg7 Rg2+ 2. Kf1 Rf2+ 3. Ke1 Re2+ 4. Kd1 Rd2+ 5. Kc1
Rc2+ 6. Kb1 Rb2+ 7. Ka1 Rxa2+ 8. Kb1 Rb2+ 9. Kc1 Rc2+ 10. Kd1 Rd2+ 11. Ke1 Re2+
12. Kf1 Rf2+ 13. Kg1 Rg2+ 14. Kxg2 Rxh2+ 15. Kxh2 Bxf7
15 224 FailHigh 1. hxg7! Rg2+ 2. Kf1 Rf2+ 3. Ke1 Re2+ 4. Kd1 Rd2+ 5. Kc1
Rc2+ 6. Kb1 Rb2+ 7. Ka1 Rxa2+ 8. Kb1 Rb2+ 9. Kc1 Rc2+ 10. Kd1 Rd2+ 11. Ke1 Re2+
12. Kf1 Rf2+ 13. Kg1 Rg2+ 14. Kxg2 Rxh2+ 15. Kxh2
15 265 +0.92 1. hxg7 Rg2+ 2. Kf1 Rf2+ 3. Ke1 Re2+ 4. Kd1 Rd2+ 5. Kc1
Rc2+ 6. Kb1 Rb2+ 7. Ka1 Rxa2+ 8. Kb1 Rb2+ 9. Kc1 Rc2+ 10. Kd1 Rd2+ 11. Ke1 Re2+
12. Kf1 Rf2+ 13. Kg1 Rg2+ 14. Kxg2 Rxh2+ 15. Kxh2 Bxf7
16 513 +1.01 1. hxg7 Rg2+ 2. Kf1 Rf2+ 3. Ke1 Re2+ 4. Kd1 Rd2+ 5. Kc1
Rc2+ 6. Kb1 Rb2+ 7. Ka1 Rxa2+ 8. Kb1 Rb2+ 9. Kc1 Rc2+ 10. Kd1 Rd2+ 11. Ke1 Re2+
12. Kf1 Rf2+ 13. Kg1 Rg2+ 14. Kxg2 Rxh2+ 15. Kxh2 Bxf7 16. gxf7
So it gets the "real" fail-low at ply 14 and shows the correct move 2. Kf1 after
83 seconds, including the entire correct line. The score goes up again in the
following plies, although I admit that it is far from a convincing winning
score.
There are several programs which show 2. Kf1 very quickly (e.g. Goliath 3.6,
also Yace), but with a 0.00 score and repetition of moves (Kf1-g1-f1); however,
I did not let them calculate for very long... (Maybe they will find the
continuation with positive score a little later.)
By the way, I do not think that 2. Kxg2 is lost - in fact, it should be drawn.
Only after 2. ... Rxh2+ 3. Kxh2 Bxf7, you have to find 4. Nxd7!:
[D]1N6/3pkbP1/6P1/8/pp3P2/8/P6K/8 w - - 0 4
Here is my analysis in PGN-format:
[Event "?"]
[Site "Notebook"]
[Date "2002.07.25"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "0-1"]
[SetUp "1"]
[FEN "1N4br/3pkPp1/6PP/8/pp3P2/8/P4r1P/6K1 w - - 0 1"]
1. hxg7 Rg2+ 2. Kf1 $1 (2. Kxg2 $2 Rxh2+ 3. Kxh2 Bxf7 4. Nxd7 $1 (4. gxf7 $2
Kxf7 5. Nxd7 b3 6. axb3 a3 $1 {0-1}) 4... Bxa2 5. Nc5 a3 (5... Kf6 6. Nxa4 Kxg6
7. Nc5 Kxg7 {1/2-1/2}) 6. Nd3 Kf6 7. Nxb4 Bg8 8. Kg3 Kxg6 9. Kf3 Kxg7 10. Ke3
{1/2-1/2}) 2... Rf2+ 3. Ke1 Re2+ 4. Kd1 Rd2+ 5. Kc1 Rc2+ 6. Kb1 Rb2+ 7. Ka1
Rxa2+ 8. Kb1 Rb2+ 9. Kc1 Rc2+ 10. Kd1 Rd2+ 11. Ke1 Re2+ 12. Kf1 Rf2+ 13. Kg1
Rg2+ 14. Kxg2 Rxh2+ 15. Kxh2 Bxf7 16. gxf7 Kxf7 17. Nxd7 Kxg7 18. Nc5 a3
0-1
Regards, Munjong.
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