Hi all 
Good to hear your opinions.
It has a kind of connection with the topic posted by Mr77 about the head to head statistics. 
Three numbers can say about the strength of the player. Of course first is the rating itself, the second is the win percentage, the third one is Avg opponent rating. Each of them we can see on FOD, on 

http://www.playcurling.com/toplist.html

 . Of course if it were possible I would have added the forth number , diversity percentage of the opponents, if we can say that. That is the  number of total different users played  with certain player divided by the total matches played by him/her. Let’s  say, for instance, the FOD rating of MrDiversity is 200. His win percentage is 63%. Average opponent rating is 245. Diversity is:  150 opponents / 2000 matches played = 7.5%. Here with the diversity is one thing. We do not know this number. Since it’s not available on FOD. Let’s say it were available. Let’s say the highest diversity of 7.5% gets the above player MrDiversity, his number we take as 100%, because he’s on the top of the list. Any other player gets diversity percentage relative to MrDiversity’s. Another player, lets say MrCurling played 100 different players and the total game is 2000, his diversity 5%, his FOD diversity (relative to the topplayer, MrDiversity) is 5%/7.5% =67%. Other parameters of MrCurling: rating is 300, win percentage is 51%, avg opponent rating is 220. So:
MrDiversity Rating combined Number is : 200*0.63*(245/200)*1= 154
MrCurling Rating combined Number is : 300*0.51*(220/300)*0,67= 75
So we can see MrDivercity has it twice as high since he played more players(% wise!), his winning percentage is higher and the average rating of his opponent is higher. This Combined number will give more or less the true value of the strength of the player. Quite often we can see how low or average rating players win our weekly tournament, the fact which only proves which is said above.
Lots of players don't play for the rating ,they are in the low rating numbers and some of them are quite strong. 
Sorry for the long post.