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Subject: Re: Perfect Chess Is Approximately ELO 4000

Author: Sune Fischer

Date: 15:31:01 02/27/02

Go up one level in this thread


On February 27, 2002 at 16:09:28, Robert Hyatt wrote:

>On February 27, 2002 at 09:41:16, Sune Fischer wrote:
>
>>On February 27, 2002 at 09:09:05, Uri Blass wrote:
>>
>>>On February 27, 2002 at 06:33:17, Sune Fischer wrote:
>>>
>>>>On February 26, 2002 at 14:35:32, Uri Blass wrote:
>>>>
>>>>>The difference in elo in order to win a match 2*10^1000-1 is certainly finite
>>>>>and I believe that choosing a random move is going to be enough for better score
>>>>>because I believe that it is possible to get at least a draw in less than 500
>>>>>moves and the probability to be lucky and choose every one of them is more  than
>>>>>1/100 in every move because I believe that the number of moves in every ply is
>>>>>going to be less than 100 when the opponent choose the perfect strategy.
>>>>
>>>>Yes I agree, but much depends on what the *chess-tree* really lookes like.
>>>>Maybe black has a forced draw in 30 moves? Maybe the forced draw is really 2000
>>>>moves? As you have previously pointet out yourself, the longer the game, the
>>>>greater the chance that the weaker player will make a mistake. This will
>>>>probably correlate directly to the rating of the perfect player, can he drag the
>>>>game on forever his rating will be much higher.
>>>>
>>>>>It suggest the following question
>>>>>suppose that A has rating 0(I believe that the player who choose random move
>>>>>will have rating that is lower than 0).
>>>>>
>>>>>suppose B wins against A 2*10^1000-1
>>>>>
>>>>>What is going to be the rating of B based on the elo formula?
>>>>>This rating is probably an upper bound for the rating of the perfect player
>>>>>if you assume that the perfect player plays only against A.
>>>>>
>>>>>Uri
>>>>
>>>>Why should it be an upper bound?
>>>>Your rating should be a constant no matter who you play, if your opponent is
>>>>weak you will win more games, but your expected score will also be that much
>>>>higher.
>>>>
>>>>-S.
>>>
>>>The rating is dependent in the opponet that the perfect player chooses to play.
>>
>>No it is not, look at the formula, it is a normal distribution.
>>
>>>The perfect player may get 100% against my program on p800 because my program is
>>>a deteministic program that always does the same mistake so if you assume the
>>>perfect player plays only against my program then the perfect player is going to
>>>get infinite rating.
>>
>>Your program is deterministic by your own words, so must score even worse than
>>one doing random moves.
>>
>>>The perfect player may get 100% against a player with a rating of 2000 when the
>>>same player is going to fail to get 100% against a player that is clearly weaker
>>>but not deterministic.
>>
>>
>>Please do not ignore the small differences in probability, they are important.
>>A 2000 elo player may be beaten by 10^30:1 and a 1000 elo player by 10^35:1, it
>>should all add up to the same rating for the perfect player, that is how the elo
>>table works.
>>
>
>That can't possibly be right.  When two players play, they have a probability
>of winning and the Elo formula will increase one player's rating and decrease
>the others until the difference between their ratings reflects the probability
>of each winning or losing.

Yes, and your point would be..?
My point was, that a person will keep his rating whether he's playing 1500
opponents or 2500 opponents (if he plays enough games). There is no way to
increase you rating by playing a lot of stronger or weaker players, it should
remain constant (assuming you won't learn and improve from the games,
naturally).

>But if I play a brick, and I win _every_ game,
>my rating will climb for _every_ victory.  And it doesn't climb by some
>amount that has a limit of zero at the upper end.  It climbs by some positive
>amount for every win.  That spells +infinity...

Again this is one of those absurd examples, a brick has -infinity rating or
what? What is the elo of the brick, we need to know that to find your elo.

-S.



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