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Rational Ranks

Posted: Thu May 15, 2014 2:46 pm
by SmoothOper
So why aren't ranks rational. I mean it would make for so many better games if a player was 1.5 kyu and another 2.1 to play essentially even.

Re: Rational Ranks

Posted: Thu May 15, 2014 2:53 pm
by DrStraw
SmoothOper wrote:So why aren't ranks rational. I mean it would make for so many better games if a player was 1.5 kyu and another 2.1 to play essentially even.


Hhm! For one thing, 1.5 and 2.1 are decimal, not rational. And secondly, the difference is 0.6 which rounds to 1 and so they should play on a one stone handicap.

Re: Rational Ranks

Posted: Thu May 15, 2014 2:55 pm
by Shawn Ligocki
I think this is how AGA ranks work, they are fractional numbers and you round to see what handicap to use. I've heard some go servers will also use custom komi/reverse-komi to make up for fractional difference in rank.

Re: Rational Ranks

Posted: Thu May 15, 2014 2:59 pm
by Shawn Ligocki
See for example, the handicap section of the AGA On-Line Self-Paired Tournament Rules.

Re: Rational Ranks

Posted: Thu May 15, 2014 3:01 pm
by Shawn Ligocki
DrStraw wrote:Hhm! For one thing, 1.5 and 2.1 are decimal, not rational.


To be fair (and pedantic :) ), they are rational numbers (numbers that can be expressed as ratios), 3/2 and 21/10. But maybe fractional would be a clearer term to use.

Re: Rational Ranks

Posted: Thu May 15, 2014 3:08 pm
by RBerenguel
Shawn Ligocki wrote:
DrStraw wrote:Hhm! For one thing, 1.5 and 2.1 are decimal, not rational.


To be fair (and pedantic :) ), they are rational numbers (numbers that can be expressed as ratios), 3/2 and 21/10. But maybe fractional would be a clearer term to use.


Pedantic++

They are decimal representations of rational numbers.

Re: Rational Ranks

Posted: Thu May 15, 2014 3:14 pm
by illluck
RBerenguel wrote:
Shawn Ligocki wrote:
DrStraw wrote:Hhm! For one thing, 1.5 and 2.1 are decimal, not rational.


To be fair (and pedantic :) ), they are rational numbers (numbers that can be expressed as ratios), 3/2 and 21/10. But maybe fractional would be a clearer term to use.


Pedantic++

They are decimal representations of rational numbers.


Agreed, they are both rational and decimal.

Re: Rational Ranks

Posted: Thu May 15, 2014 3:18 pm
by Mef
The answer is typically "tradition" however some places do use the rating difference in lieu of ranking difference. As mentioned, AGA self paired tournaments do this, and I believe IGS does as well (or at least they used to).

Re: Rational Ranks

Posted: Thu May 15, 2014 3:20 pm
by SmoothOper
RBerenguel wrote:
Shawn Ligocki wrote:
DrStraw wrote:Hhm! For one thing, 1.5 and 2.1 are decimal, not rational.


To be fair (and pedantic :) ), they are rational numbers (numbers that can be expressed as ratios), 3/2 and 21/10. But maybe fractional would be a clearer term to use.


Pedantic++

They are decimal representations of rational numbers.


Yes, yes, rational numbers are like PhDs degrees, on paper only.

Re: Rational Ranks

Posted: Thu May 15, 2014 3:59 pm
by hyperpape
DrStraw wrote:For one thing, 1.5 and 2.1 are decimal, not rational.
This is why daddy drinks.

But to go to the highest possible point of pedantry, with vain hopes that it will end this, 2.1 is a number (of what sort, we probably can't say, though it's not an integer). '2.1' is a linguistic entity that represents a number (you might call it a decimal representation, though you might also reserve that for a particular type of abstract object).

As to the original question, I hold the apparently unpopular opinion, (influenced by playing a lot of other abstracts and the OGS ladders) that reduced handicaps are good. So I'm (good god, what is happening?) in partial agreement with you, SmoothOper.

Re: Rational Ranks

Posted: Thu May 15, 2014 3:59 pm
by Abyssinica
My next ranking goal is going to be 5i! :D

Re: Rational Ranks

Posted: Thu May 15, 2014 4:08 pm
by DrStraw
Abyssinica wrote:My next ranking goal is going to be 5i! :D


Why think small? Why not try the quaternions?

Re: Rational Ranks

Posted: Thu May 15, 2014 7:09 pm
by ez4u
DrStraw wrote:
Abyssinica wrote:My next ranking goal is going to be 5i! :D


Why think small? Why not try the quaternions?

Abyssinica is just admitting what we all know in our hearts, for us amateurs our ranks are all imaginary anyway. :blackeye:

Re: Rational Ranks

Posted: Thu May 15, 2014 11:09 pm
by RBerenguel
hyperpape wrote:
DrStraw wrote:For one thing, 1.5 and 2.1 are decimal, not rational.
This is why daddy drinks.

But to go to the highest possible point of pedantry, with vain hopes that it will end this, 2.1 is a number (of what sort, we probably can't say, though it's not an integer). '2.1' is a linguistic entity that represents a number (you might call it a decimal representation, though you might also reserve that for a particular type of abstract object).

As to the original question, I hold the apparently unpopular opinion, (influenced by playing a lot of other abstracts and the OGS ladders) that reduced handicaps are good. So I'm (good god, what is happening?) in partial agreement with you, SmoothOper.


I felt the universe shaking

Re: Rational Ranks

Posted: Fri May 16, 2014 11:56 am
by Solomon
I thought my rank (5.98343) was rational (598343/100000), but actually it's irrational (11 * sqrt(6 * log(pi)/pi)/e).