Author: Robert Hyatt
Date: 07:33:21 01/30/02
Go up one level in this thread
On January 30, 2002 at 02:05:30, Uri Blass wrote: >On January 30, 2002 at 00:09:27, Robert Hyatt wrote: > >>On January 29, 2002 at 14:19:26, Uri Blass wrote: >> >>>On January 29, 2002 at 14:08:45, Robert Hyatt wrote: >>> >>>>On January 28, 2002 at 16:57:35, Joshua Lee wrote: >>>> >>>>>>>Congrats on taking the initiative. >>>>>>> >>>>>>>Can we assume that this is a DOS program and that it is related somehow to the >>>>>>>Russian mainframe chess program of the old days? >>>>>> >>>>>> >>>>>>Even less than you can assume Crafty is related to Cray Blitz. :) >>>>> >>>>>This is basically the version that was rewritten into "Turbo-C" and from the >>>>>documentation has refinements from the version that played in the 2nd Computer >>>>>Olympiad in London 1990. It is about as close as we can get to the actual >>>>>mainframe version from the 70's. So like Crafty is related to Cray Blitz , so is >>>>>this PC version of Kaissa. I would like to mention something fairly obvious but >>>>>yet interesting that is where Kaissa in 1972 played Komsomolskia Pravda Readers >>>>>it took 90 minutes in one instance to search 1,500,000 this PC version on a >>>>>1Ghz it searched 2,673,745 in 56 seconds. Huge increase from 200-300 Positions >>>>>per second i'd say. The readers played Spassky in 1971 in two games and drew one >>>>>and lost the other. Spassky at that time was 2690 which would put the readers >>>>>average at 2490. Kaissa managed the same result against the readers losing one >>>>>game and drawing the other which would put it's average at 2290. >>>> >>>>The problem is that the way they searched in 1974 has _nothing_ to do with the >>>>way they searched in 1990. Ditto for Blitz in 1977 WCCC, vs Cray Blitz in >>>>the 1983 WCCC event. There is simply nothing comparable between those two >>>>programs, even though I wrote _both_. Faster hardware completely changed the >>>>way the search was used... And it changed what could be evaluated as well... >>> >>>You tried to write a strong program when you wrote Cray blitz. >>>I believe that they did not try to write a strong program after 1974 so you >>>cannot know that they searched in a different way. >>> >>>Uri >> >> >>However I _do_ know that Kaissa 1974 was a strong program for that time >>period. And there were a few "brute force" programs running at the time >>and they all got smashed due to 3-4 ply searches max... > >I believe that the reason that brute force programs got smashed was the fact >that the programmers did not know to use brute force correctly and did not use >killer moves. Killer moves were mentioned in Greenblatt's paper. Chess 3.x used them. My chess program used them. Chess 4.x (which was written in 74 or 75) specifically mentioned them in the book chapter that described the program. > >Kaissa was the first program to use some techniques that are used today by >almost every program and killer moves is one of them and probably the most >important one. not at all. Killer moves were known well before that. > >This is about kaissa from the book how computers play chess: > >"an improvement of the alpha beta search was obtained by using what the >programmers called the "best move service" >they point out that in chess the number of possible moves(less than 10000) is >far smaller than the number of possible positions and a classification of the >moves is therefore much easier than a classification of positions. >The underlying principle of the best move service is that a move that was the >best in many similiar positions would be plausible in the current position >For each ply 10 moves were stored. These were the move that were most frequently >the best ones..." > >Uri They also claimed to have developed bitboards on their own, which is probably true. But chess 4.0 also developed bitboards at the same time, apparently independently. And chess 4.0 _clearly_ had killer moves from the "Chess Skills in man and machine" book chapter...
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.