Author: Will Singleton
Date: 08:11:49 05/20/03
Go up one level in this thread
On May 20, 2003 at 02:17:14, Tim Foden wrote:
>On May 19, 2003 at 23:46:58, Will Singleton wrote:
>
>>I was trying to figure out why my latest build doesn't do quite as well on
>>ecm86, and I ran Ruffian on it. To my surprise, Ruffian couldn't solve it, even
>>given 5 minutes. This is odd, since most other progs can do it in less than 10
>>seconds. (What I take away from this exercise is that my program must now be
>>stronger. Otherwise, I'd have to work on the problem, which is much less
>>interesting than testing new ideas.)
>>
>>[D]2r3k1/1nqbrp2/p5pp/1p1Pp1N1/8/1P5P/P1B2PP1/2RQR1K1 w - -
>
>I would assume then (from running Green Light), that Nxf7 is the correct move
>here?
>
>The PV is interesting as it contains 9 captures in a row at the start of the PV.
> Maybe ruffian is pruning if there are more than a certain number of captures in
>a row (as this is very unlikely to be a good thing).
>
>Cheers, Tim.
>
>Analysis: GLC3.00, AXP 1.47GHz, 24MB Hash:
>
> Game stage: Middle game
> Current eval: 0.564
> Ply Time Score Nodes Principal variation
> 4 0.000 +0.743 5646 Ne4 Qb6 2. Qd2 g5
> 5 0.010 +0.592 13917 Ne4 Nd6 2. Nf6+ Kg7 3. Qf3 Kh8
> 5 0.020 +0.592 21231 Ne4 Nd6 2. Nf6+ Kg7 3. Qf3 Kh8
> 6 0.060 +0.702 54001 Ne4 Qb6 2. Qd2 g5 3. Qb4 Nc5
> 6 0.070 +0.702 66151 Ne4 Qb6 2. Qd2 g5 3. Qb4 Nc5
> 7 0.200 +0.709 159535 Ne4 Qb6 2. Bd3 Ree8 3. Qd2 g5 4. Nc3
> 7 0.310 +1.102 263663 Nxf7 {++} Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+
> Kxf7 5. Rxc1
> 7 0.360 +1.745 307058 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1
> 7 0.370 +1.745 316180 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1
> 8 0.440 +1.345 388531 Nxf7 {--} Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+
> Kxf7 5. Rxc1 Nd6
> 8 0.530 +1.186 460490 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6
> 8 0.580 +1.186 527044 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6
> 9 0.841 +1.259 749293 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7
> 9 1.081 +1.259 966741 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7
> 10 1.712 +1.299 1514631 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke7
> 10 2.093 +1.299 1853467 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke7
> 11 3.985 +1.340 3477228 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke7 7. g4
> 11 5.377 +1.340 4753269 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke7 7. g4
> 12 8.251 +1.405 7132424 Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8
> 12 11.666 +1.405 10151k Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8
> 13 19.798 +1.603 16605k Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8 8. Rc7
> 13 25.416 +1.603 21432k Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8 8. Rc7
> 14 40.958 +1.591 33530k Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8 8. Rh7 Nf7
> 14 58.534 +1.591 49298k Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8 8. Rh7 Nf7
> 15 1:50.67 +1.731 89853k Nxf7 Rxf7 2. Bxg6 Qxc1 3. Qxc1 Rxc1 4. Bxf7+ Kxf7
> 5. Rxc1 Nd6 6. Rc7 Ke8 7. Ra7 Bc8 8. Rh7 Nf7 9.
> Rg7
>
Tim,
Interesting. Your line shows a transition to a fairly even endgame, yet GLC
doesn't see it until the moves are played through. Perhaps the problem some
engines have here is going from middle to endgame. Could be like Tony said, a
reliance on preprocessing sets up middlegame parameters that aren't valid at the
end of the pv. Or it could be simply a bug, something that prevents the endgame
phase from being fully triggered during the search.
At least I know why mine takes a bit longer now. It takes more time to see the
proper pv (not recapturing with the queen), because I reworked my pawn hash to
include the endgame parameter.
Will
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