Rational Ranks

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SmoothOper
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Rational Ranks

Post 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.
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Re: Rational Ranks

Post 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.
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).
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Re: Rational Ranks

Post 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.
Last edited by Shawn Ligocki on Thu May 15, 2014 3:02 pm, edited 1 time in total.
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Re: Rational Ranks

Post by Shawn Ligocki »

See for example, the handicap section of the AGA On-Line Self-Paired Tournament Rules.
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Re: Rational Ranks

Post 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.
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Re: Rational Ranks

Post 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.
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Re: Rational Ranks

Post 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.
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Re: Rational Ranks

Post 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).
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Re: Rational Ranks

Post 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.
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Re: Rational Ranks

Post 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.
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Re: Rational Ranks

Post by Abyssinica »

My next ranking goal is going to be 5i! :D
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Re: Rational Ranks

Post by DrStraw »

Abyssinica wrote:My next ranking goal is going to be 5i! :D


Why think small? Why not try the quaternions?
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).
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Re: Rational Ranks

Post 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:
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Re: Rational Ranks

Post 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.


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Re: Rational Ranks

Post by Solomon »

I thought my rank (5.98343) was rational (598343/100000), but actually it's irrational (11 * sqrt(6 * log(pi)/pi)/e).
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