Author: Daniel Clausen
Date: 01:20:56 11/15/02
Go up one level in this thread
On November 14, 2002 at 13:34:05, Ron Murawski wrote: >On November 14, 2002 at 03:26:47, Daniel Clausen wrote: > >>On November 14, 2002 at 01:47:38, Ron Murawski wrote: >> >>[snip] >> >>>A computer never knowingly plays a true sacrifice. All it can do is make the >>>move that will get it the highest score, aka "best move". >> >>And that is different to how humans play a sacrifice exactly how? Computers >>are a bit more number-centric than humans, but that is true for the >>non-sacrifice-moves as well as the sacrifice-moves. >> > >The distiction is this: a human can make a move based on gut-instict or based >on experience from playing other similar positions, a computer cannot. My point was that this is also true for non-sacrifices. And about the gut-instinct: there was this Novag board computer several years ago (ForteC or something was its name, but I'm not sure. maybe Guetti knows? :), which played so-called PSH-moves (in german: passt sicher halbwegs) which were moves like Bxh7+ in situations where the computer thought that this could be a good attacking chance, although it didn't see the full consequences in the calculated tree yet. >If a chess player knows his opponent he might play a slighly inferior move >knowing that the other player is uncomfortable in certain situations whereas a >chess engine will never play a slightly inferior move. Things like "asymetric king evaluation" could do that too. (if it's turned of against GMs but not against 'normal humans') >In order to get a computer to play a true sacrifice, you have to give a large >enough positional bonus to fool the engine into thinking it's gaining >something. Define "true sacrifice"? It's a bit difficult to discuss this stuff.. What am I supposed to tell you when you tell me that the Kramniks play sacrifices because of intuition, gut instinct and whatnot, and if a computer plays a sacrifice then it's not a "true sacrifice" because it's just some positional bonus somewhere.. What if I'd do the following in my engine: For every "sacrifice" (for the moment, I define a move a sacrifice if the engine doesn't see a material equality/advantage after the PV - hey, at least I come up with a definition! ;) my engine plays, I mark this move (eg Bxh7+) in a permanent hashtable/list. Now my engine plays in a tournament and sees 2 moves as promising in a certain position: Be4-e2, with a score of +0.5 (material +0, eval +0.5) Be4xh7+, with a score of +0.4 (material -2, eval +2.4) Now my program looks in this other 'sacrifice-list' I mentioned before and decides to play Bxh7+ because it won 10 games with this sacrifice before (and only lost 1), whereas the move 'Be2' doesn't have an entry. What is this now? If a human does that, it's probably "based on experience". If my engine does that it's "just adding some positional bonuses"? Of course it would be a clever list, which would only add "Bxh7+" to the list, if blacks kingside would still be in good shape otherwise (pawns on f7, g7, h7, rook on f8, king on g8) And other things which improve the 'quality' of the sacrifice-list. :) Sargon
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.