Author: blass uri
Date: 13:40:54 06/13/00
Go up one level in this thread
On June 13, 2000 at 15:45:28, Christophe Theron wrote: >On June 13, 2000 at 08:36:24, Oliver Roese wrote: > >>On June 12, 2000 at 05:46:59, Rémi Coulom wrote: >> >>>On June 10, 2000 at 13:44:35, blass uri wrote: >>> >>>>On June 10, 2000 at 11:54:17, Ed Schröder wrote: >>>> >>>[...] >>>>> >>>>>Maybe the opposite is true. It depends per program how the programmer >>>>>looks at things. For this position I would say that having 2 outside >>>>>passers usually is a great advantage and as such is rewarded by a chess >>>>>program. If so then this position is an exception to the rule. And the >>>>>end-game is full of exceptions much more than the mid-game. >>>>> >>>>>Ed >>>> >>>>Having 2 outsides passed pawns is an advantage but having 2 advanced passed pawn >>>>is also an advantage. >>>> >>>>The problem is to know which advantage is bigger. >>>> >>>>I agree that it is not a simple problem and I understand the fact that >>>>programmers prefer to waste more time about other problems. >>>> >>>>I still believe that it is possible to see it at evaluation time by an array >>>>64*64*64 of distance to promotion. >>> >>>You are perfectly right about this idea. I do it in TCB. I have a table for >>>distance to promotion for KPK and PPK. In fact, it is not really a table of >>>distance to promotion, but a table that gives the maximum number of "not a King >>>move by the opponent" before the pawn is promoted. I call it "extended square of >>>the King". It is not in the latest version of TCB. I will make it available in >>>the next version. If programmers are interested in the code to generate the >>>table, I will send it to them. >>> >>>PPK is nice, but KPK is probably much more useful. TCB can solve WAC #100 in 25 >>>seconds or so on a celeron 400 thanks to it. It saves 3 or 4 plies as compared >>>to the standard "square of the Pawn" rule (or is it "square of the King"?). It >>>is also very good at detecting that a pawn can win a tempo by checking the >>>opponent on its way to promotion. >>> >>>I do not think it would solve this position though. I am not a good chess >>>player, but the position after the Queen exchange seems unclear to me. Black can >>>promote first, but White will promote on the next half move. Is it a winning >>>advantage? Or I might be missing something. I will try it on TCB when I am back >>>home. >>> >>>Greetings, >>>Remi >> >>Here is a human-like approach: >>Apply the rule of the "wandering square". I got it from Awerbachs book about >>pawnendings: >> >>[D]8/8/1k6/8/P2P4/8/8/K7 w - - 0 1 >> >>In the above diagram the two white pawns are on the corners of a square >>(a4-d4-a7-d7). The rule say, that the two pawns are unstoppable by the opposite >>king, if their common square has reached the edge of the board. >>Since this is not the case, here black has hope to stop the pawns. (He will hold >>the draw with 1..Ka5). >> >>[D]Q3q3/4k3/8/5p2/2p5/8/P6P/4K3 w - - 0 1 >>This position is from blass uri. >>According to the rule the white pawns are unstoppable. >>But the blacks pawns are unstoppable to, after the unavoidable ...f4. >>Since we have no dumb advice here, a search is required. It reveals, that black >>wins after 1.Qxe8+ but he is only up a tempo. >> >>Oliver Roese > > >Your rule is interesting, but I have a hard time believing that it holds when >the pawns are on their original square. A pawn on its original square can move >two squares up (or down), and that should imply a special case for your rule, >isn't it? > > > > Christophe The rule is not correct in another case [D]8/8/PkP5/8/8/8/8/7K w - - 0 1 The rule is that white wins but it is a draw. Uri
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