"David Richerby" wrote in message
...
Mike Murray wrote:
"Jerzy" wrote:
Do you think that there is an exact formula for giving e.g. time
odds ? ;-)

Never heard of one, but here's what pops into my head: Split the
total time available by the inverse of the odds predicted by the
difference in Elo.

This doesn't work. The Elo rating was calculated from games at
classical time controls and it is only predictive for those games.


Evidence, please. It is a gross misconception that ratings are
administered with a view towards increasing their predictive value.
That is a miniscule factor at best. The reason that organizations
have different types of ratings is that, essentially, these organizations
are selling a product and have determined that the consumers do not
*want* their blitz games to influence their classical ratings. It
does *not* follow that blitz games do *not* predict classical results.
Of course they do, at least to a degree.

What if an organization decided to offer time-of-day ratings. Games
played in the morning were given one rating. Games played in the
evening were given a different rating. Still no predictive value?

Knowing the two players' Elo ratings allows you to estimate the
probability of A beating B at classical time controls. Suppose A
usually beats B in long games. Nonetheless, it might be that A gets
very nervous when playing blitz so does very badly, while B is a blitz
specialist who doesn't do all that well at classical time controls.
But your scheme will give less time to A, the weaker blitz player.

(Or A might tend to use all of his two hours, while B tends to bash
out his moves quickly.)

It's also not clear to me that your time division is the right way of
doing it but that doesn't matter so much as the whole idea is, I'm
afraid, flawed.

Making some sort of time division based on Elo ratings from rapid
games would be a better approximation. It would still suffer from the
problem I described but, perhaps, to a lesser extent: for example, A
might be OK at 5-minute chess but really hate 2-minute chess, which is
what he might end up being forced to play.


Dave.

--
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