Author: Dieter Buerssner
Date: 13:21:11 06/26/02
Go up one level in this thread
On June 26, 2002 at 13:53:11, Andrew Williams wrote:
>This is a null-move problem, caused by a stupid bug in PM. My null-move
>verification search was not working in this position. Now that I've fixed it,
>this particular error doesn't occur. I'm still interested in what others see
>here.
For Yace, I cannot see much influence of null move here. I tried without null
moves at all, with default null move usage (R=2, including a verification
search) and with R=2 without any verification search. Each time I see a big fail
low at depth 9 for Kg3. Of course without null move, many more nodes are used.
Without verification search, somewhat less nodes are used than in the analysis
shown here.
Default parameter, 20M hash, K6-2 475.
[Board displays can be found at the start of the thread.]
3R4/5k2/1p1p4/1NbP2pp/2P3P1/P7/5rKP/8 w - -
26559 0.502 0.00 7t 1. Kg3 h4+ 2. Kh3 Rf3+ 3. Kg2 Rf2+ 4. Kh3 {70}
27503 0.511 0.00 7. 1. Kg3 h4+ 2. Kh3 Rf3+ 3. Kg2 Rf2+ 4. Kh3 {70}
77693 0.806 0.00 8t 1. Kg3 h4+ 2. Kh3 Rf3+ 3. Kg2 Rf2+ 4. Kh3 {70}
80881 0.833 0.00 8. 1. Kg3 h4+ 2. Kh3 Rf3+ 3. Kg2 Rf2+ 4. Kh3 {70}
296766 2.173 -0.40 9-- 1. Kg3 h4+ 2. Kh3 Rd2 3. Rd7+ Kf8 4. Rd8+ Ke7
5. Nxd6 Bxd6 6. c5 bxc5 7. Rc8 {-270}
327844 2.378 -1.40 9-- 1. Kg3 h4+ 2. Kh3 Rd2 3. Rd7+ Kf8 4. Rd8+ Ke7
5. Nxd6 Bxd6 6. c5 bxc5 7. a4 {-270}
447722 3.062 -2.66 9t 1. Kg3 h4+ 2. Kh3 Rd2 3. Nxd6+ Ke7 4. Ne4 Rd3+
5. Kg2 h3+ 6. Kf1 Kxd8 7. Nxg5 Bxa3 {-350}
617198 3.879 -2.65 9t+ 1. Kh3 Rf3+ 2. Kg2 Rd3
782050 4.871 0.00 9t 1. Kh3 Rf3+ 2. Kg2 Rf2+ {70}
786579 4.900 0.00 9. 1. Kh3 Rf3+ 2. Kg2 Rf2+ {70}
1035362 6.321 0.00 10t 1. Kh3 Rf3+ 2. Kg2 Rf2+ {70}
1078614 6.596 0.00 10. 1. Kh3 Rf3+ 2. Kg2 Rf2+ {70}
3R4/5k2/1p1p4/1NbP2pp/2P3P1/P5K1/5r1P/8 b - - 0 1
83167 0.816 0.00 7. 1...h4+ 2. Kh3 Rf3+ 3. Kg2 Rf2+ 4. Kh3 {-70}
260767 2.058 0.40 8++ 1...h4+ 2. Kh3 Rd2 3. Rd7+ Kf8 4. Rd8+ Ke7 5.
Nxd6 Bxd6 6. c5 bxc5 7. Rc8 {270}
291453 2.261 1.40 8++ 1...h4+ 2. Kh3 Rd2 3. Nxd6+ Ke7 4. Rc8 Bxd6 5.
c5 bxc5 6. Rg8 {270}
422097 3.004 2.52 8t 1...h4+ 2. Kh3 Rd2 3. Nxd6+ Ke7 4. Re8+ Kd7 5.
Rd8+ Kxd8 6. Nf7+ Kd7 7. Nxg5 Bxa3 8. Ne4H Rd4H
{350}
446599 3.145 2.52 8. 1...h4+ 2. Kh3 Rd2 3. Nxd6+ Ke7 4. Re8+ Kd7 5.
Rd8+ Kxd8 6. Nf7+ Kd7 7. Nxg5 Bxa3 8. Ne4 Rd4
{350}
1081782 6.687 2.92 9++ 1...h4+ 2. Kh3 Ra2 3. Nxd6+ Ke7 4. Rc8 Rxa3+ 5.
Kg2 h3+ 6. Kf1 Bxd6 7. Ke2 Bxh2 8. Kd2 {350}
1291166 7.878 2.93 9t 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3H gxh4+H 7. Kf4H Rf2+H 8. Ke4H
h3H {350}
1351892 8.156 2.93 9. 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+ 7. Kf4 Rf2+ 8. Ke4 h3
{350}
2147021 12.174 3.06 10t 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+ 7. Kf4 Rf2+ 8. Ke4 h3
9. a4 {350}
2316019 12.962 3.06 10. 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+ 7. Kf4 Rf2+ 8. Ke4 h3
9. a4 {350}
2496656 14.024 3.46 11++ 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+ 7. Kf4 Rf2+ 8. Ke4 h3
9. Kd4 h2 10. Kd3 {350}
3796744 20.190 3.76 11t 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+ 7. Kf4 Rf2+ 8. Ke4 Kg5
9. a4 Rf4+ 10. Ke5 Kxg4 {430}
4182628 21.888 3.76 11. 1...h4+ 2. Kh3 Ra2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+ 7. Kf4 Rf2+ 8. Ke4 Kg5
9. a4 Rf4+ 10. Ke5 Kxg4 {430}
8269311 41.953 4.16 12++ 1...h4+ 2. Kh3 Rc2 3. Rh8 Bg1 4. Nxd6+ Kg6 5.
Rxh4 Rxh2+ 6. Kg3 gxh4+H 7. Kf4H Rf2+H 8. Ke4H
Kg5H 9. Kd3H Kxg4H 10. Ke4H {HT} {430}
11056858 55.122 4.23 12t 1...h4+ 2. Kh3 Rc2 3. Nxd6+ Ke7 4. Re8+ Kxd6 5.
Re6+ Kd7 6. Re1 Bd6 7. Rh1 Rxc4 8. Rd1 Rc3+ 9.
Kg2 h3+ 10. Kf2 Bxh2 11. a4 Bd6 {350}
BTW. Disabling razoring shows Kh3 one depth earlier (independent of null move).
Regards,
Dieter
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