Author: Mark Young
Date: 05:05:28 05/19/99
Go up one level in this thread
On May 19, 1999 at 02:55:48, Dave Gomboc wrote: >On May 18, 1999 at 22:52:23, Mark Young wrote: > >>On May 18, 1999 at 22:18:47, Dave Gomboc wrote: >> >>>On May 18, 1999 at 21:38:19, Mark Young wrote: >>> >>>>On May 18, 1999 at 20:16:35, Dann Corbit wrote: >>>> >>>>>On May 18, 1999 at 19:55:02, Mark Young wrote: >>>>>[snip] >>>>>>Incorrect logic and reasoning...Humans find moves this was all the time...its >>>>>>called positional play. >>>>>Of coures. And when they do find it, they know it is a good move. They would >>>>>not say, "Now I am down 1.5 pawns to my opponent." >>>> >>>>Are you a chess player, this statement is total ********. They don't know its a >>>>good move or winning move all the time...but they THINK its the best move (BM) >>>>in the position. >>>> >>>>The eval is meaningless, you can have a eval that shows anything. What is >>>>importent is if it plays the correct move and correct line. If it finds the >>>>correct move and line because it see all the other moves and lines are worse, or >>>>because it sees that 1 move and line wins, is no difference. Both methods are >>>>valid, and both are use by computers and humans. >>>> >>>>Think about what BM stands for, Best Move... Both methods can find the correct >>>>move and line of play, and have equal value in the real world and in a over the >>>>board game. >>>> >>>> >>>> >>>>> >>>>>In the same way, a chess program that thinks it is behind has not found the >>>>>right move yet. >>>>> >>>>>If you don't put down a bm for H7 to look for, it does an excellent job. If you >>>>>do put one down it does some bad things that make for crappy data. That was my >>>>>point, which you have failed to grasp. >>>>> >>>>>When you put down a bm and H7 immediately stops, it is not because of some >>>>>positional brilliancy. It is because it happened, at that iteration, to look >>>>>better than the other moves. Yet if the eval is still negative, it does not >>>>>know why the move was chosen. It just stopped. >>>> >>>>I will write slow so you understand. I don't care what or what not hiarcs7 finds >>>>because a BM input, or if it does something strange with the BM. I did not >>>>search the position with the BM. If Hiarcs7 were playing a real game, and got to >>>>those positions it would have played the BM and correct line. >>> >>>Some balance here is necessary. Some people are content to say that if a move >>>is selected as best, this is good enough. Other people insist on seeing a score >>>accompanying the move that accurately reflects the theoretical value of the >>>position after the move is played. >>> >>>It is important that an accompanying score is accurate. This certifies that the >>>software has seen its way through whatever complications may be present. >>>Changes to the position that do not interfere with the themes that support the >>>main line of play will not prevent a solution from being found. >>> >>>It is important that the best move is played, even if the accompanying score is >>>not accurate. This certifies that the software understands enough about the >>>position to make its way forward correctly -- for the moment. It is useful to >>>identify that a move is likely to be the most promising, even if a definitive >>>conclusion has not been reached. >>> >>>It is fair to say that the while the former is better, the latter is often >>>adequate. If the software's assessment of a position is highly perturbed by >>>"small" (read: irrelevant) changes to a position, then it could be said that >>>much "luck" is involved in it choosing a particular move or another. More >>>often, though, assessments do not vary widely between positions with "small" >>>(again read: irrelevant) changes, and in this case, it is partially the >>>consistency of the assessing that allows the proper move to frequently be >>>chosen, even without the discovery of a tactical verification, or tactical >>>refutation of alternatives. >>> >>>So, in testing, prefer a proper score, but do not ignore a proper best move >>>without a proper score. It is still doing something right: give it half credit. >> >>What is the proper score, any + score, a huge +score....the only proper score of >>a winning positions is mate in n. >>> >>>Dave > >This is a valid question. I think that a "proper score" is one that is high >enough relative to the alternative scores that a certain path is absolutely >guaranteed to be selected (including from perturbations of the position to be >played from.) This is different from the usual notions of "seeing that it can >win the piece", et cetera: a sufficient, but not necessary criteria for matching >my "good enough" score. > >If the scores for all of the moves but the best one are abysmal, then it has >found that only one move is playable, even if you don't see that it wins (or is >actually not good enough anyway!, but is still the best move because it holds >off a resignable position as long as possible.) If the scores for four or five >moves are roughly even, this isn't really good enough to score "full points" >IMO. > >We can see that if the program reaches a position that it presumed to be okay >(in an earlier search), but sees that it is resignable when it gets there, it's >toast. Finding a "proper" score at some earlier stage would have allowed it to >avoid the error completely by not playing to the bad line. The major idea >behind singular extensions is to see what is happening at the "end of the >tunnel": you can see those fail-highs and fail-lows early enough that you can do >something about them (head towards the position, or avoid it.) Programs that >see "proper scores" from further back in the game are going to be stronger than >those that don't, ceteris paribus. So what you are saying is the program has to see it tacticly, or it does not count. Programs have other aspects to them then just there search, and I see nothing wrong with a program finding the correct move by seeing the other line get killed, instead of seeing this one move wins. You did not really answer the question, and we are back at square one. All of what you are saying is subjective thus anyone can reject any BM played by any program producing almost any score. You are trying to split the baby and I don't think it can be done. You need to show me how this is workable with some examples. > >Dave
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