Author: Uri Blass
Date: 13:38:50 09/06/01
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On September 06, 2001 at 16:08:59, Robert Hyatt wrote: >On September 06, 2001 at 15:14:43, Uri Blass wrote: > >> >>I did not say that programs can see the repetition but that they can >>see Kh1 for good reasons. >> > >There we will just have to disagree. The only "good reason" to play Kh1 >is something _concrete_. IE "I played that because I saw that if I played >Kf1 I would walk into a perpetual." Or "I played Kh1 because I saw that if >I played Kf1 I would lose a pawn." Or something reasonable. Just choosing >Kh1 makes little sense. The king should centralize unless there is some >compelling reason why it should not. And Kh1 is not centralizing anything >at all. H1 is one of the worst 4 squares on the board for a king to >occupy, _unless_ there is a compelling reason for it to sit there. > >If DF can't see a compelling reason, it is just choosing it for random >(and wrong) reasons... > >I have had my program choose the right move for the wrong reason, on many >occasions. I try to fix those as I consider them "bugs" and not "good >luck things." > > > >> >>The reason that Kh1 does not give black the chance of Qe3 >>is good enough. >> >>Humans are also going to choose Kh1 even without seeing the >>draw by Qe3 if they understand that after Kf1 Qe3 black has chances >>when after Kh1 black has no chances and has to go to a losing endgame. >> > >Kh1 or Kf1 doesn't actually prevent Qe3. Kh1 prevents Qe3 with similiar results and I am not talking about perpetual check. After 44.Kf1 Rb8 45.Ra6 Qe3 black can get few pawns for the piece before the perpetual check. After 44.Kh1 Rb8 45.Ra6 Qe3 is simply a losing move I also see that I remembered wrong and Deep Fritz does not see 45...Qe3 in the main line when it analyzes move 44 of white and it simply avoids 45.Ra6 in the main line before changing it's mind because it believes that 45.Qd7+ is better. When I give it to analyze move 45 it can see Qe3 in the main line before changing it's mind to 45.Qd7+ that is probably also drawing. It just means that if the king is >on f1, there is a possible perpetual, while if the king is on h1 there is not. >But the queen can go there either way. Which is why I discount any program >playing either move unless they see _the_ reason for the move. programs cannot see everything by search. I did not talk about the static evaluation of the position after Qe3 but about the static evaluation of the position some moves after Qe3 that is the reason for avoiding Kf1. > > > > > >>It is about king safety's evaluation >>The micros can see that the white king is not safe after Kf1 >>and black has chances by Qe3 when deeper blue could not see it. > >I don't believe that for a minute, otherwise DF would not keep getting >tricked by king safety issues against Nemeth. If it could understand that >Kf1 is worse than Kh1 based on evaluation, Nemeth would not keep mating the >program with straightforward attacks. > > >> >>It is possible that deeper blue saw that both kings are not safe and >>simply added king safety scores. > > >That is possible. Or it saw that both _are_ safe since no program can >see the resulting perpetual after Kf1. And given that both appear to be >equally safe if you can't see the draw, then Kf1 is more logical. > > > >> >>If it did it then it is clearly wrong to do it because if both kings >>are not safe you cannot be sure about the result and the evaluation >>should be closer to a draw. >> >>Uri > >That sounds like Gandalf. It doesn't work. I do not understand what gandalf has to do with it. Uri
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