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Re: KGS ranking revisited
Posted: Wed May 09, 2012 4:08 pm
by speedchase
Then wouldn't you have to wait until it actually trickled down?
Re: KGS ranking revisited
Posted: Wed May 09, 2012 4:40 pm
by wms
emeraldemon wrote:Is there a reason not to anchor the strongest players at 9d and let it trickle down?
Yes, a very strong one. That means that as the strogest player rank changes, everybody shifts by the same amount. When the strongest player stops playing, if the 2nd strogest player is 2 stones weaker, then suddenly everybody jumps two stones.
Our current system sometimes has some changes when anchors are adjusted, but overall it is far more stable than anything based on a single player would be.
Re: KGS ranking revisited
Posted: Wed May 09, 2012 5:51 pm
by snorri
I'm not really fond of the stochastic walk ratings seem to take on KGS even when you don't play and I certainly don't like the expiration to '?' when you don't play for a while, but overall it may be the most accurate system in current use for players who play there regularly.
Other servers have had resets. IGS did some years ago (and I mean before the 2005 change, somewhere in the summer of 2002 when there was a 3-stone shift. I wasn't playing then so I don't know for sure. I guess right before than an IGS 1d was pretty darn kickass relatively speaking.)
If I wanted to get attached to a number, I'd buy a certificate.
Re: KGS ranking revisited
Posted: Wed May 09, 2012 6:17 pm
by hyperpape
Pippen: my point was that if that's what you want, you can't complain about KGS, since it's just one rating system among many.
Aligning all the ratings systems would require collaboration from around the world, and would also happen to be impossible at the present time.
Re: KGS ranking revisited
Posted: Wed May 09, 2012 8:25 pm
by jts
snorri wrote:I'm not really fond of the stochastic walk ratings seem to take on KGS even when you don't play ...
It's not really stochastic, is it? It assumes that you would be able to beat the same people you were able to beat when you were last playing.
Re: KGS ranking revisited
Posted: Wed May 09, 2012 10:41 pm
by Ortho
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Re: KGS ranking revisited
Posted: Thu May 10, 2012 1:49 am
by daal
jts wrote:snorri wrote:I'm not really fond of the stochastic walk ratings seem to take on KGS even when you don't play ...
It's not really stochastic, is it? It assumes that you would be able to beat the same people you were able to beat when you were last playing.
Yes, it assumes that while you were gone that you've been playing on Tygem.

Re: KGS ranking revisited
Posted: Thu May 10, 2012 12:45 pm
by jts
daal wrote:jts wrote:snorri wrote:I'm not really fond of the stochastic walk ratings seem to take on KGS even when you don't play ...
It's not really stochastic, is it? It assumes that you would be able to beat the same people you were able to beat when you were last playing.
Yes, it assumes that while you were gone that you've been playing on Tygem.

Well, not necessarily. If your most recent partners decline, you'll decline to. It just assumes that, in the absence of evidence, you can still beat the same people and lose to the same people.
Re: KGS ranking revisited
Posted: Thu May 10, 2012 1:34 pm
by witwit
The amount of importance some people are placing on ranks in this thread is quite silly. The most important thing for a ranking system is to be internally consistent, ie trying to have differences in rank equate to 50/50 games with the appropriate number of handicap stones. Why does it matter if there is a "shift" in rankings and some bits associated with your account on a remote server change from 5k to 7k? All that matters is your actual strength which can never be characterized by a single number but by comparison.
Re: KGS ranking revisited
Posted: Thu May 10, 2012 1:46 pm
by RobertJasiek
witwit wrote:The most important thing for a ranking system is to be internally consistent
A system with sudden shifts IS inconsistent.
Re: KGS ranking revisited
Posted: Thu May 10, 2012 2:20 pm
by hyperpape
Robert, like it or not, he's arguing about a reasonably well-defined concept. The fact that you don't like using the word "consistent" in naming that concept (which could naturally be named "momentary internal consistency") is pretty much irrelevant.
Re: KGS ranking revisited
Posted: Thu May 10, 2012 10:34 pm
by RobertJasiek
One should not call an inconsistent system consistent.
Re: KGS ranking revisited
Posted: Thu May 10, 2012 10:55 pm
by daal
RobertJasiek wrote:witwit wrote:The most important thing for a ranking system is to be internally consistent
A system with sudden shifts IS inconsistent.
But he said internally consistent. If everyones rank is affected in the same way by the recalibration, the system will be just as good at predicting an even match as it was before.
Re: KGS ranking revisited
Posted: Fri May 11, 2012 12:04 am
by RobertJasiek
A rating system moving too many players upwards is internally inconsistent because a rating system shall be able to distinguish players instead of creating heaps of fake strong subpopulations.
Re: KGS ranking revisited
Posted: Fri May 11, 2012 3:13 am
by SpongeBob
RobertJasiek wrote:... heaps of fake strong subpopulations.
That sounds scary ...