Wednesday, October 29, 2008

ELO Demystified

What is ELO

ELO is a rating system originally used in chess championships. It has been adopted by many other games and sports as a rating system. Many websites now use this system.

How does ELO work

ELO rating system is based on yours and you opponents rating. These ratings are used to determine how likely you were to win or lose. This is best shown in an example:

If your rating is 1300 and your opponents rating is 1200. By looking at those numbers you can see that you would be expected to win. This of course doesn't always happen!

Assuming you win this game, your rating might go up 1 or 2 points for the win. However if you lose, your rating may go down 3 or 4 points. This is because you were expected to win.

If you win all game you are expected to win, your rating will climb slowly, if you win some you are not expected to win your rating will climb faster.

On the flip side, if you lose games you are expected to lose, your rating will drop slowly, If you lose a game you were expected to win , your rating will decrease more rapidly.

Summary

elo is a good indicator of your current form. To use an example:
Earlier this year, I would consider myself as playing well (backgammon) my rating climbed to about 1390, somewhere between then and now, I lost my form, lost a few games, so my rating has dropped to about 1300. I would consider this a good indicator of form, at 1390 I was playing good backgammon, once I lost form , my rating dropped , so now while at 1300 I will give you a hard fought game, I am not quite as potent as I was when my rating was up to 1390.

You will find in time that you will have strings of good games and strings of bad games , but eventually will find your place and while your rating will go up and down it will hover in the same area.