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Re: KGS ranking revisited

Posted: Wed May 09, 2012 2:08 pm
by Pippen
oren wrote:
Pippen wrote:I'm all for KGS ranks matching to EGF.


Why choose EGF? :)


Because EGF has ambitious ranks. A 1d EGF will almost always beat 1d's of other systems. What I wouldn't like and what would me make leaving KGS would be if a 1d KGS was a 7k on IGS or stuff like that.

Re: KGS ranking revisited

Posted: Wed May 09, 2012 2:10 pm
by oren
Pippen wrote:Because EGF has ambitious ranks. A 1d EGF will almost always beat 1d's of other systems. What I wouldn't like and what would me make leaving KGS would be if a 1d KGS was a 7k on IGS or stuff like that.


Just to make sure I have it right, you want to align it to EGF since EGF ranks look lower than the rest. Is that correct? If you're 1d kgs you get moved to something lower?

Re: KGS ranking revisited

Posted: Wed May 09, 2012 3:09 pm
by jts
oren wrote:
Pippen wrote:Because EGF has ambitious ranks. A 1d EGF will almost always beat 1d's of other systems. What I wouldn't like and what would me make leaving KGS would be if a 1d KGS was a 7k on IGS or stuff like that.


Just to make sure I have it right, you want to align it to EGF since EGF ranks look lower than the rest. Is that correct? If you're 1d kgs you get moved to something lower?

It's worth noting that EGF claims 7d is pro strength, whereas KGS has pros with ranked accounts who are actually 9d. If I made a JTS rating system in which 1d was pro strength, then a JTS 1d would beat the pants off a EGF 1d.

Re: KGS ranking revisited

Posted: Wed May 09, 2012 3:18 pm
by wms
I don't remember the exact half life of games. I think that it currently ages down based on the average ranks of the players at the moment the game was played. Not perfect but that was done to give stronger players better rank stability while weaker players (who change rank faster) won't be dragged down as much by older games.

Meanwhile, in the past week there was a change in the anchors. The anchors had been neglected in the past few months, and some anchored players hadn't been playing as reliably as we want so it had caused shift in the rank system. We're trying to correct that now, but when you fiddle with the anchors there will always be some jumps up and down in the system.

Re: KGS ranking revisited

Posted: Wed May 09, 2012 4:05 pm
by emeraldemon
Is there a reason not to anchor the strongest players at 9d and let it trickle down?

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. :lol:

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. :lol:

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.