In chess they have the elo rating system. It seems to work pretty well. When you play against an opponent, your opponents rating and your rating are taken into account, and after the result your ratings are adjusted. You gain points if you win and lose points if you lost the match. You gain more points if your opponents rating was relatively higher than your original rating. You gain less points if your opponents original rating was lower than yours etc. If you want exact details about chess elo you could probably find out about it on the internet i'm sure.

Now, why can't poker have a system like this? This would work very well online. Everytime you win a pot your rating is adjusted. It is adjusted by a number that depends on all the opponents that played in the pot and how much money they put in and what their rating is.

If you win alot of money off a really good player you get more points. If you win a little you get much less points. If you win a lot of money off a poor player you would get less points than if you had won the money off a good player. It could be a complex formula that would accurately reflect skill over the long run. I don't care exactly how it is computed, I'm sure they could figure something out that works well.

Then there is a second number to show how reliable your rating is. The more hands you play the more reliable your rating.

This would mean that the world champion would have to play online poker.

Why isn't there already a rating system like this for online poker? Well I think poker players are more worried about money than judging there skill.