About ELO rating - Guild Wars Forums

Yanman.be · Jul 03, 2006, 05:38 PM // 17:38

Guild Wars uses the ELO rating. Fine.

According this article http://gw.gamewikis.org/wiki/Rating , the correct formula to calculate the probability of winning is this one (using brackets ): p = 1/(1+(10((x-y)/400) where X is the enemy, and Y is your rating.

When I use this formula, to calculate the probability to win of a guild of my alliance ( 1111 rating ) and our guild ( 1125 rating ), I get a probability of 1.5384 . As far as I know, probabilities should be between 0 and 1 right? Any numbercruncher wanting to help here?

I'm creating some quick program to calculate our odds in a guild battle, how many points we win/lose etc. But it seems this formula is flawed, or I did something wrong.

EDIT stupid me...the exact formula : p = 1/(1+(10^((x-y)/400)

The probability now is 0.52, wich is normal.

cR4zY-n^ · Jul 03, 2006, 06:44 PM // 18:44

Rather rely on your skills imo. :P

VGJustice · Jul 03, 2006, 06:59 PM // 18:59

Quote:

Originally Posted by Barbie

Math is hard.

Quoted for Truth.

Yanman.be · Jul 03, 2006, 06:59 PM // 18:59

Gives us a morale boost

EDIT what do you mean with that VGJustice?

Jul 03, 2006, 05:38 PM // 17:38	#1
Yanman.be Banned Join Date: Dec 2005 Location: Belgium Guild: [ROSE] Profession: A/	About ELO rating Guild Wars uses the ELO rating. Fine. According this article http://gw.gamewikis.org/wiki/Rating , the correct formula to calculate the probability of winning is this one (using brackets ): p = 1/(1+(10((x-y)/400) where X is the enemy, and Y is your rating. When I use this formula, to calculate the probability to win of a guild of my alliance ( 1111 rating ) and our guild ( 1125 rating ), I get a probability of 1.5384 . As far as I know, probabilities should be between 0 and 1 right? Any numbercruncher wanting to help here? I'm creating some quick program to calculate our odds in a guild battle, how many points we win/lose etc. But it seems this formula is flawed, or I did something wrong. EDIT stupid me...the exact formula : p = 1/(1+(10^((x-y)/400) The probability now is 0.52, wich is normal. Last edited by Yanman.be; Jul 03, 2006 at 05:52 PM // 17:52..

Jul 03, 2006, 06:59 PM // 18:59	#4
Yanman.be Banned Join Date: Dec 2005 Location: Belgium Guild: [ROSE] Profession: A/	Gives us a morale boost EDIT what do you mean with that VGJustice? Last edited by Yanman.be; Jul 03, 2006 at 07:04 PM // 19:04..

Jul 03, 2006, 06:44 PM // 18:44	#2
cR4zY-n^ Frost Gate Guardian Join Date: Jul 2005 Location: Zadar - Croatia Guild: We Work As A [Team] Profession: Mo/E	Rather rely on your skills imo. :P