This is a really good Forum Post. It really cleared up alot of misconceptions for me and my friends. There is one error I think may be possible. Right now I don't even have an xbox 360, I simply bought a gamertag and put it on my friend's xbox for the time being. I have only played in games where my friends were in the same games with me, and yet we are not the same rank. Besides maybe a few games my friend has played without me (a very small amount), we have nearly the same win/loss ratio and the same games played, but I have a higher rank. This would lead me to believe that how well players do in games (MVP, Medals, K/D Ratio, ... , ETC) does have some kind of effect on the players rank. I'm not saying that the model posted here is inaccurate; on the contrary, I think it is well thought out and most likely very accurate to what is actually used, but I noticed this inconsistency and thought I should let everyone know to think about it. Reply what you think!