How is pound for pound rated?

I want to know if there is a legit pound for pound rating.
Because even though Winky Wright may be beter than Jermain Taylor, he didn't beat Bernard Hopkins, even though I personally don't think Jermain Taylor won against B-Hop that's how it was judged. But that's besides the point. Most P4P lists have Winky always in the top 3 and Jermain in the bottom 3. Can any body shed some beams for me?

i think its rated on ability and potential or somethin along those lines.

However you want to rate it, there's no standard way

Some people just rate it on who they think is the best fighter if everybody weighed the same, other people just go only by accomplishments, most people probably base it on a combination

Then, there's also SaltheButcher who's got his own completely unique way of doing it

P4P is a hard thing to explain...Ouma said it pretty well off the cuff though.

A lot of it is based on ability...record...longevity...& then that evil little thing called...opinion. ;D

its basically the greatest fighter in the world today

There is not such thing. Sure the media likes it, they like anything they can use as bait. Comparing boxers in different weight classes is like comparing boxers from different generations. Its fun to talk about, but its all speculation. Roy Jones was considered P4P for a long time. But look what happened when he got hit solid. Same is gonna happen to mayweather if he messes with Shane Mosley. Mosley is just as fast and WAY stronger. Bad move Mayweather.