Author: Komputer Korner
Date: 20:49:26 05/13/05
Go up one level in this thread
On May 12, 2005 at 18:31:52, Dann Corbit wrote: >Bookups backsolving is basically a minimax algorithm + refutations. > >ChessAssistant does the same thing. > >It is a very good idea. > >IMO-YMMV. The following explanation will prove that I am the real KK. Compare my answer with logical opening theory articles and the 10 kommandments I did 5 years ago. The problem is that minimax is only useful to a computer. We humans have brains. All one has to do is put a chess engine to work at any node to get an evaluation. Usually the evaluation will be less than a pawn. If it is more than a pawn, then 99.9% of the time the line is busted for one of the sides. If it is less than a pawn, then the decision for the White side is how much of a pawn advantage do you need before continuing with the line? The opening advantage is about .13 of a pawn. If any subsequent node has an evaluation of more than that then the line is worth persuing. I have often argued that the famous unclear symbol is actually the same as the +/=/= that you sometimes see, which is the opening advantage for white at the 1st move. White does not want to lose the opening advantage, because if he/she does then instead of getting a 56% score of the games he/she ends up with only a 50% score from positions that are dead equal. Any GM will tell you that playing from equal positions as white will lose them a lot of money compared to playing from positions thst are unclear or slightly better for them. That is why they all drop lines where Black has been shown to equalize. The situation is this. If White can force an advantage of more than .2 of a pawn then Black players stop playing that line. If Black can force equality then White players stop playing that line. Therefore the only lines that get repeated are the unclear and the tiny advantage for white lines. We humans don't need a backsolving algorithm to tell us what lines to play. The only time when backsolving would be useful is if by pressing a button one could have a computer immediately tell us all the drawing lines if Chess is a draw and all the winning lines if Chess is a win. Of course that will never happen. so in the meantime we all keep adjusting our repertoires with results from games and results from analysis (human or computer engine). So back to the first sentence. once you have a computer analyze a line(or if you do it yourself) if you simply put an evaluation against that node at move 12 why do you need backsolving to fill in all the subsequent nodes by backtracking back up the tree from move 30 back to move 12? Isn't it much better to have the computer analyze the 12.Ng5 node and then put an evaluation against it than have the 30.Nxg6 node analyzed and then backsolve back up the tree to 12.Ng5?? What purpose does it serve to have all the individual nodes in one line attached with evaluations when those nodes are not really part of the opening? Openings are differentiated from the rest of the tree because they are lines that have been proven over the years under practice to be worth repeating. Anybody who thinks backsolving has merit is trying to treat chess as if it is one big opening puzzle with perfect information. Of course, openings cannot be solved with backsolving. Even the name is wrong. Backsolving does not solve anything. It merely attaches an evaluation to each node based on an evaluation far down the root of the tree. What use is that when there will be thousands of novelties subsequently found as side lines which will put that line out of business anyway. It is much better to analyze the 12.Ng5 node than to analyze the nodes at move 30. Even GMs who do deep opening analysis have first exhaustively analyzed the nodes at move 12,13,14,15,16,17,18... etc before they do the nodes at move 30. We will never have perfect information and the chess puzzle will never be completely solved. I would be very very surprised if any GM ever admitted to ever using the backsolving feature. My expose of backsolving stands. It is simply a waste of bytes.
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