I think a different perspective would be insightful when considering Halo 2's ranking system. While it is certainly true that a less skilled individual may undeservingly win a match when they are matched up with much better teammates, this is and was unlikely to be a consistent enough occurance to really affect their 1-50 rating. Over the course of 100 games, if an individual cannot carry their own weight, they are more likely to lose in any given game. If 5 of those 100 games they are matched with much better teammates and win where they otherwise would not, that is still not enough to overcome all the should-lose games that would result due to poor skill. Just like in any game of odds, there are likely to be very low statistical chances that the unexpected may occur. However, these anomolies will soon become negligible over the course of many repititions.
Furthermore, although at first it seems counterintuitive, basing ranking off of individual performance in terms of kills, assists, etc. actually lends itself to selfish play and undervalues team play. It was the case in Halo 2 that the emphasis on winning and not individual stats lead to an increased appreciation for teammates that were able to aid the team without producing great stats. If you went 8-10 in a slayer match, but were careful not to give up power weapons or bleed points to the other team, you may be considered an asset. Perhaps those 8 kills were clutch or you sacrificed yourself 10 times to help a teammate escape with a power weapon. Perhaps you were the flag carrier or bait in an objective gametype. Sure, it was great to look at stats as a good measure of skill in Halo 2, but there was so much more value in doing whatever it took to win. If you had to drive the warthog all game to run flags or for a skilled gunner, it was worth going 0-5 or 1-3 to get the win.
I guess what I'm saying is that while stats have their place and should obviously continue to exist so that we can analyze each others' play, Halo 2 had the right idea. When it came right down to it, it was play to win and you had to be prepared to do whatever your team needed you to do.
