Author: Sune Fischer
Date: 14:29:34 10/27/02
Go up one level in this thread
On October 27, 2002 at 17:13:59, Uri Blass wrote: >On October 27, 2002 at 16:59:48, Sune Fischer wrote: > >>On October 27, 2002 at 15:46:07, Uri Blass wrote: >>> >>>My definition of 1 ply error is an error that computer can see a big change in >>>the score based on a search of one ply. >> >>Are you kidding. That sacrifice was very deep, he calculated for 45 minutes. >>What a computer thinks at 1 ply is irrelevant, it can't possibly have seen a >>fraction of the considerations Kramnik did. > >Irrelevant. No, because most sacrifices are too deep for a 1 ply search (that's why they are called sacrifices!). You give something now and hope later on to gain back more material or checkmate, or maybe just to get a lot of initiative. >Playing a bad sacrifice is still an one ply error even if the selective search >of kramnik could not see the refutation. > >> >>>The mitsake of kramnik in game 5 was 1 ply error because after the mistakes >>>programs can see in 1 ply that kramnik is losing a piece(they search the first >>>move check and extend after the moves because they extend checks and after it >>>they go to qsearch but it is enough for them to see that kramnik is losing a >>>piece. >> >>I might agree with you if you include regular qsearch on top of that 1 ply, but >>if they do extensions at 1 ply and actually find the refutation only at 10 plies >>deep, then it's of course a 10 ply error. The iteration counter is just an >>arbitrary number in that context. > >I think from the point of view of chess programs and most programs can see >at depth 1 after kramnik's mistake that kramnik is losing because they do check >extensions and do capture in the qsearch. By your definition a 1 ply error would depend on the program, a 1 ply error for program X might be a 4 ply error to program Y, so I don't like this definition. The ply depth of the error must depend on the depth of the refutation line, and not on the program. >>>The mistake of kramnik in game 6 is also 1 ply error because programs can see >>>big change in the score based on search of 1 ply. >>>I do not agree that the refutation is more than 1 ply. >>>Programs usually evaluate from the first ply that the sacrifice is wrong. >>> >>>Playing sacrifices for the beauty and not because they are correct is a mistake >>>of weak players and not of players at the level of kramnik. >> >>I don't think so, chess is art and chess players have different styles. > >The best chess players see it first as a sport. Yes, but also as an art, I know Kasparov has used that word:) >>As the saying goes: "when you have found a good move, look for a better one". > >Yes but spending a lot of time on analyzing a move that you suspect to be better >does not make sense when you already have a good move. Kramnik must have thought it was deadly. >>Clearly Kramnik wanted to play the beautiful sacrifice, but be also wanted to be >>sure it was correct, hence the 45 minutes of thinking. >>He must have miscalculated, that's all (I don't conspire to him losing on >>purpose). If his opponent had been a human, things might have been different :) > >I suspect that GM's will have no problem to find the right defence in 120/40 >time control. > >The only case when kramnik did something similiar against humans was against >anand and anand had no problem to win. Computers are well know to have a bad sense of danger, take a look at Nemeth's games, he lures out the king and checkmates easily, for instance. >Uri
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