From: md85-epi@byse.nada.kth.se (Urban Koistinen)
Subject: Re: Computer Ratings/Versions
Organization: Royal Institute of Technology, Stockholm, Sweden
Date: Sat, 15 Aug 1992 12:19:10 GMT

    One of the main virtues of CCR is that they take several sources into
    account.  They give each and the mean.  They also do their own
    testing.
    
    But, if you are asking about the process and not looking for specific
    ratings, I still think you get the best sense of things from CCR, and
    you do get some criticism of the process as well.  It's only about $10
    a year, and you can get back issues.
    
    But, if you just wanted an answer to your question, my impression is
    that official ratings are currently in a state of chaos.  Machines have
    been rated by different processes, but the original ratings were not
    taken away.  Read CCR for details.  Otherwise, I can only say that
    precise ratings are really not that important.  I don't know the
    standard deviations off hand....ok, I have a program that computes
    ratings: 20 games gives a standard deviation of 63 points.  So, what do
    we make of the fact that one program is rated 50 points more than
    another?  I think we should make nothing of it, after all, the probable
    error for 20 games is 43 points.  And once I decide that I am going to
    give the chess program only 1 minute per move, I have trimmed about 150
    points off its strength.  So just buy a something that is rated (by
    CCR) *at least* 200 points above you.
    
    And what do we make of the Fidelity ratings?  As I recall, the Mach III
    is 2265 and the Mach IV is 2325.  Well, that is within 1 standard
    deviation for 20 games.  (And the standard deviation for 40 games is
    still 43.)  And, as I recall, the Mach IV retails for a lot more than
    the III.  That means that some people are paying a lot of extra money
    for a machine that is not significantly better.  We can be reasonably
    sure that IV is better than III because they differ only in the
    hardware.  In effect, some people are apparently willing to pay a large
    premium to have the latest and the greatest even though vastly superior
    is already on its way.
    
    --Jim

You might want to look at the list SSDF publish.
SSDF is an association of computer chess enthusisiasts, some of which
help update the list by playing computer v computer matches.
The ratings reported are usually based on 500+ games, all played at
tournament level.
In the full list both the number of games played and the average rating
of the opposition is listed as well as a confidence interval withing wich
the score is with a 95% probability.
Usually the interval is about +-50 rating points.

I think SSDF charge 60 SEK for bimonthly lists and 120 SEK for monthly.
That is approximately $12/year and $24/year.
I think they also tell the score between the different machines.
If you want information on how to order, ask me or better, look it up
in the ICCA journal.

Below are the ratings of some machines.

From 'The Swedish Rating List' from the ICCA Journal 1992 #2.
I hope there are no typos, it look right to me.

Mephisto Lyon           68030 36MHz     2259
Mephisto Portorose      68030 36MHz     2244
Mephisto Vancouver      68030 36MHz     2238
Chess Machine Schroder  512K ARM2 16MHz 2232
M_Chess 1.1-1.66        80486 33MHz     2187
Fidelity Elite          68030 32MHz     2127
Fidelity MACH IV        68020 20MHz     2087
Fritz                   80386 25-33MHz  2033
Rex Chess 2.3           80386 25-33MHz  2033
Zarkov 2.5              80386 25-33Mhz  2012
Psion Atari             68000 8MHz      1878
ChessMaster 2100 (Amiga)68000 (Amiga)   1875
ChessMaster 2000 (Atari)68000 8MHz      1850

Notice: subtract 50 to get ELO-rating, add 50 to get USCF rating.

I will happily forward any comments to SSDF.
I try to read posted messages too.

-- 
Urban Koistinen - md85-epi@nada.kth.se