Author: Slater Wold
Date: 15:19:49 10/06/01
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On October 06, 2001 at 16:36:47, Bruce Moreland wrote: >On October 06, 2001 at 01:54:57, Slater Wold wrote: > >>Well Bruce, with all due respect, you're kinda funny on these things. >> >>You seem to have a "threshold" for a winning move. Which I guess makes some >>sense, but it is very arguable. >> >>If Program-A looks at any given position and says, "I am winning by 6+ pawns, >>and here is my mainline" then it's winning. However if Program-B looks at the >>same exact position and says, "I am winning by 3+ pawns, and here is my >>mainline" it would seem by your standard, it's not winning. What if the >>mainlines are the same? What if Program-A rewards certain things differently >>than Program-B? >> >>It's kind of like you disagreeing that DJ7 solved Nolot #3. It did. It >>followed Baudot's mainline to a *tee*. And you still don't think it's solved >>because DJ7 says it's only winning by "x" amount. Which I guess is not above >>your threshold. It thinks the move is best, it has the mainline just as >>described by Baudot, how is that not solving the problem? >> >>I agree, programs should strive to find the *best* possible move. But a winning >>move is a winning move, right? >> >>It's sort of like drag racing; it doesn't matter if you win by an inch, or by a >>mile. A win is a win. > >It is easy to make a position where one side will score very high, but the game >is drawn. > >In the root position of WAC 100, white has connected passed pawns in an ending, >and this is going to score big. > >There are plenty of positions where connected passed pawns won't win, and yet >the score is still big. > >A big score isn't enough, sometimes, especially in tricky cases like this where >white has a high score from the root. I can show you positions from real games >where one program said +7 or so and drew. The particular case I'm thinking, one >side had a protected passed pawn on the seventh, *and* an extra bishop, against >a pawn, and couldn't win. So this is KBPP (both pawns healthy and neither was a >rook-pawn) vs KP, drawn via 50-move rule. > >If white has no plan in WAC 100 and just shuffles pieces for 50 moves, it will >show +3 or whatever for the entire time. It is hard to say that a program has >found a win, when you see that happen in a 12-ply search or whatever. > >+7 is more likely to be a win. I didn't follow the main line out, but stuff was >advancing and things were being captured. I think it's clear that both Be3 and >b6+ win, but it's not true that a program sees a win if it plays Be3 in >particular, since the move isn't committal. b6+ is an indication that a program >sees something, but Kb3 indicates nothing, by itself. > >In the case of Nolot 3, Junior had +0.7 and the right line. That indicates a >preference for the Nxg5 line. The opinion about the Bxg5 line is probably not >that much different. > >Fine, Junior preferred the key move, but it didn't feel that it could force a >position that it believed to be significantly better. > >I'd give it credit for finding the key move, but it's not like it came back with >a score of +5. > >Mostly, we are trying to compare search functions with Nolot, not evaluation >functions. There's a difference between "finds the line" and "solves the >problem". > >Some of the Nolot position have been "finds the line" by various programs for >years. > >The first time I published a result for a Nolot position, which was in 1994, I >indicated that one of the "solutions" my program found was not convincing, for >this reason. I showed that the key could be found, but not necessarily that it >was understood. > >I acknowledge that in Nolot 3, the key can be found. > >bruce I just think that you should respect a mainline, more than an eval. Evals are very volatile, while mainlines are more solid. Once again, Program-A sees a position as winning, and gives it a +6.00 score. Program-B sees the _SAME_ exact moves, and gives it +3.00. Which is correct? The one with the bigger eval? I just don't think that can be trusted. Slate
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