Author: Jouni Uski
Date: 01:14:54 11/29/00
Go up one level in this thread
On November 29, 2000 at 02:53:28, Howard Exner wrote: >On November 29, 2000 at 01:12:46, Ed Schröder wrote: > >>On November 28, 2000 at 20:15:16, Bruce Moreland wrote: >> >>>On November 28, 2000 at 17:16:25, Ed Schröder wrote: >>> >>>>On November 28, 2000 at 14:38:33, Robert Hyatt wrote: >>> >>>>>I personally don't feel very "safe" if my program is doing something good for >>>>>the completely wrong reason(s) it found... yes, I like to see it do the right >>>>>thing, period. But those "wrong reason" cases cause me to remember that for >>>>>every right move, wrong reason, there will also be wrong move, wrong reason >>>>>cases as well. >>>> >>>>Rebel from the start position will frequently switch from 1.d4 to >>>>1.e4 >>>> >>>>Does it play 1.e4 or 1.d4 for the wrong reason? >>> >>>There's no correct answer so this isn't the same thing. A better case might be >>>LCT I position 23: >>> >>>[D]8/5Bp1/4P3/6pP/1b1k1P2/5K2/8/8 w - - 0 1 >>> >>>The key is Kg4 but fxg5 gets a similar score from my program, and it's random >>>which one it will choose in any iteration. It's seeing some of what is going >>>on, but the program is a little bit too hard, and it's hit or miss whether a >>>given version will find this, find it and switch away, switch back and forth >>>several times, or fail to find it. >>> >>>I would be dishonest if I said my program "solves" this under any conditions, >>>although if I were reporting scores for LCT 1 I would have no problem with >>>reporting a "success" for this one as long as the rules allowed for that. >>> >>>Some test suites try to get you to look at the PV and see that you are finding >>>the move for the right reasons, but this is tedious. It's easier to just do >>>time until find-and-hold. >>> >>>I don't tune for test suites. I test against ECM and LCT 1 every day, so I know >>>that I'm not losing tactical zip, so I know that I'm not doing something >>>drastically weird, and so I can see the long-term effects of my changes upon >>>node rate and search depth. >>> >>>bruce >> >>Same here, switching between 1.fxg5 and 1.Kg4 and I tend to agree on >>what you have said. In the end (19 plies) the score looks convincing >>enough to keep 1.Kg4 on the next iteration but you never can be sure. >> >>Ed >> >>================ >> >>Engine version : Rebel Century 2.01 >>Hash table size : 40 Mb >> >>8/5Bp1/4P3/6pP/1b1k1P2/5K2/8/8 w - - >> >>00:00 03.00 1.38 1.fxg5 Bd6 2.Bg6 >>00:01 04.00 1.43 1.fxg5 Bf8 2.Kf4 Bc5 >>00:01 07.00 1.88 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kd6 4.Ke4 Bc3 >>00:02 09.00 2.00 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kd6 4.Ke4 Bc3 5.Kf5 Bd4 >>00:05 11.00 2.00 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kd6 4.Kg4 Bc3 5.Kg5 Be5 6.Kf5 >>Bd4 7.Kg6 >>00:07 12.00 2.24 1.fxg5 Ke5 2.Kg4 Be7 3.h6 gxh6 4.gxh6 Bf6 5.Kh5 Kd6 6.Kg6 >>Bd4 7.Kh7 >>00:10 13.00 2.23 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kd6 4.Kg4 Bc5 5.Kh5 Bf2 6.Kg6 >>Bd4 7.Kh7 Be3 >>00:18 14.00 2.18 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kf6 4.Ke4 Bf8 5.h7 Kg7 6.Bg6 Be7 >>7.Kd5+ Kh8 8.Bd3 Bf6 >>00:30 14.04 2.18 1.Kg4 >>00:33 14.04 2.35 1.Kg4 gxf4 2.Kxf4 Bf8 3.Kf5 Ke3 4.Kg6 Kf4 5.Be8 Kg4 6.Bb5 >>Kg3 7.Be2 Kh4 8.Kf7 Bb4 >>01:07 15.00 1.98 1.Kg4 Be7 2.fxg5 Ke5 3.h6 gxh6 4.gxh6 Kf6 >>01:15 15.01 2.20 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kf6 4.Ke4 Ba3 5.h7+ Kg7 6.Bg6 >>Be7 7.Kd5 Kh8 8.Be4 >>01:53 16.00 2.20 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kf6 4.Ke4 Ba3 5.h7 Kg7+ 6.Bg6 >>Be7 7.Ke3 >>03:25 17.00 2.30 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 Kd6 4.Kg4 Bd2 5.Kh5 Ke7 6.Kg6 >>08:10 18.00 2.50 1.fxg5 Ke5 2.h6 gxh6 3.gxh6 >>12:27 18.01 2.50 1.Kg4 >>17:11 18.01 2.82 1.Kg4 Be7 2.Kf5 g4 > >This is the correct continuation, as Be7 is the best defense for black and then >white must play Kf5 in order to win. If programs latch onto this sequence their >eval should continue to increase. > >>45:50 19.00 2.61 1.Kg4 Be7 2.Kf5 gxf4 > >Another good example of the "right move for the wrong reason" is this Botvinnik >position against Kotov. Best move is g5, but after fxg5 black must avoid Kg3, >and instead follow up with the only winning move, d4. > >[D]8/8/4b1p1/2Bp3p/5P1P/1pK1Pk2/8/8 b - - bm g6g5; I have read, that also d4 is winning as first move. So there is second solution. Is this may be only different move order? Jouni
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