From: Bruce_Leverett@TRANSARC.COM
Newsgroups: rec.games.chess
Subject: Re: Inflation in ELO's system
Date: 9 Oct 92 16:52:48 GMT

Well, Player 3 looks like the career path that I'm on (substitute 1400 for
1800 as the initial rating).  From the perspective of the individual player,
I don't see the deflationary aspect.  I deflated some people's ratings when
I was young and beautiful.  But those people are gone now so who cares about
them.  Meanwhile, all the rating points I stole from the older generation,
I'm giving back to the younger generation.  What's the problem?

I'm not writing entirely in jest.  I think these ``rating pool'' arguments
must be based on some serious fallacy, because there has never been any
measurable deflation; the average USCF rating has never fallen.  Let me
try to put my finger on the problem.  You are ignoring Player 1, but I think
he is crucial (and there are far more of him than there are of Player 3).

He played in 2 tournaments and dropped out forever.  In those two tournaments
he probably went 2-8 (at best).  Eight people gained points from playing him
and two people lost.  Seems like a significant contribution to the rating
pool to me.  Especially since the two that lost points probably are going
to drop out pretty soon too.

Suppose that Player 1's first provisional rating (after the 1st tournament)
was 1100, and his last provisional rating (after the 2nd tournament) was still
1100.  Does this mean that his coming and going had no net effect on the
rating pool?  Evidently not.  His effect on the rating pool can be measured
only by the effect of his games on the ratings of his opponents; and not even
all of them, either, but only those who remain in the pool.

When a provisionally-rated player plays an established opponent, the effects
of the game on their ratings are not symmetrical.  And this is not just a
second-order problem.  All players start out with provisional ratings.  A
substantial percentage of people who get ratings drop out before getting
beyond provisional.  A substantial minority of players in every large
tournament are unrated or provisional.

What if there were no new players coming into the pool?  Then there would
indeed be deflationary pressure.  Suppose that a group of 20 C-players were
shipwrecked on a remote Pacific Island.  Assuming that they survived and
started a chess club (of course!),
they would all be much stronger chess players after a few years.  But if
they started their own little rating system, they would still have an average
rating in Class C.  So when the rescue boat picked them up, they could
terrorize all the C-players back on the mainland.  There is a basic
deflationary pressure that is exerted whenever anyone gets stronger.

But in real life, the rating pool is constantly being churned by arrivals of
new players and departures of old.  And the number of people who are exerting
deflationary pressure by getting stronger is a very small percentage of the
number of rated players.  I suggest that the deflationary pressure
caused by people getting stronger may be at least counterbalanced by the
inflationary pressure caused by a sucker being born every minute.  A priori,
I do not see that either of these pressures is necessarily stronger than
the other; their relative strengths would depend on circumstances.