Author: Bertil Eklund
Date: 11:05:43 01/18/00
Go up one level in this thread
On January 18, 2000 at 13:23:45, Vincent Diepeveen wrote: >On January 17, 2000 at 16:46:52, Rajen Gupta wrote: > >>I remember when i 1st started reading the web comp chess reports-rebel8 was the >>new champ-by a huge margin.since then there is no convincing evidence that later >>versions of rebel are stronger than rebel8. perhaps someone who does extensive >>testing like Mark Young or enrique can tell us (on the basis of actual tests and >>comp vs comp games please, not merely on subjective impressions)the following: > >About Rebel. First of all let's see what did Rebel get so high >at SSDF, as i guess that's what you refer to? > >Some months before rebel8 came out i emailed with Ed Schroeder. I emailed >asking him about whether lazy evaluation worked for him. Ed denied using >lazy evaluation. > >Some months later Rebel8 came out, basically searching a lot of nodes >a second faster than rebel7/6, apart from that i didn't have the >feeling rebel8 was much different from 7. Some say it was positionally >weaker than 6/7. Well exactly that happens when using lazy evaluation. Hi! As usual you guess and speculates all over. Rebel8 was a major step in Comp-chess, it was much stronger and MUCH MORE aggressive than its predecessors. I have played over 5000 games with R8 and followed a lot of them. > >Recently Ed said he *always* used lazy evaluation in Rebel. Ed probably >already somewhere in rebel used lazy evaluation. > >I felt rebel8 was tactical anything but weak. When it arrived it was one of the strongest. >For SSDF however rebel8 had 2 new things. >First of all a big tournament book from which each line was already >auto232 tested. The book of Rebel8 is still good, but a bit narrow. I have written a big tournament book that plays almost eveything, and the results are equal or maybe slighly worse, but the program plays very good of its own. >Secondly, and this gets really underestimated by everyone, it aborted >games that were the same, within 2 moves out of book. >Now obvious i'm not a fan of playing the same game over and over again, >but considering the nature of the book in rebel, which has some lengthy >and wide lines which >i call 'killerlines' (lines that objectively aren't representing the >state of the art theorem, but where you know in advance that you >win against certain other programs with, as they 'fall' for the line). Ed kindly supported us with the possibility to play doubles. Only use Rebel a and it plays until mate, saves and play the same game again. >So if you win 20 games from rebel8 with 1.d4 ... 2.a3 >then in fact your games get 19 time aborted >Yet if in the richter rauzer a certain Qxe5 side line wins for rebel, >then you might lose 10 games in a row, as in a positoin where you're >already dead lost, there rebel is still in book having several >possibilities. Rebel had a very "simple" book-learner and was very bad on avoiding lost games. It had no "aggressive" book-learner at all, didn´t try to repeat wins. >Further the interpretation of the games. Rebel finds in endgame pawns >worth very little. Let's look to rebel: boring openingsbook, but very >good book. No questions about that. It´s a matter of taste. >This means that a game rebel wins is usual SHORT. A game that it loses it >doesn't get bad out of book usual, so that is usual a rather long win. There was many sharp lines, yes, and when it went wrong the games could be short also. >Auto232 player aborts such a game after a certain amount of moves, then >rebel as it evaluates dead lost positions usually under -5, it puts a >'?' so a question mark as the result of the game. Games with score + or -5 was correctly reported 1-0 or 0-1, ? only if the game stopped of some reason or it ended with a stalemate. >I forgot but don't aborted games which are repeated twice are also carrying a '?' as result? No a parenthesis with a number (1) for one repetition. From Rebel9, Rebel plays on in doubles, but in the counter it´s noticed that there are doubles. >Anyway, human factor gets *heavily* underestimated when interpreting results. What is "human" factor. >I'm not sure what SSDF does, how many '?' results does Karlsson receive? ?? >Anyway, this is already enough to explain the rating jump of Rebel at SSDF. I can´t see any explanation at all from you. It simply was the best when it was new. Bertil SSDF > >>which is the strongest version of rebel > >>is rebel getting progressively weaker with each version or is this merely >>because other programmes are getting disproportionately stronger? > >Of course a program never gets weaker. Others just learn how to beat it. > >>if rebel is actually getting weaker then what is the purpose of releasing new >>versions? > >Don't you want to get updated with new versions? > >>rajen
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