Goodness, this question is asked so much. I might self when I was stuck on my 38 was wondering it too.. untill i just started playing better. But the Ranking system for Halo 3 relies on a sophisticated and modified version of Microsoft's 'truskill" Now don't quote me on this, my information is well cited but if it was perfect i would be working for microsoft, and im not. So any way you are stuck at a 27 and im assuming in Doubles. The trueskill system works on two basic valus, your uncertainty value (sigma) and your actual skill (mu). I will refer to them as sigma and mu from now on.
Your sigma is basically how the game accounts for luck; it is the numerical representation of what your skill could be. Play consistently for a low sigma, or play inconsistently for a high sigma.
Your mu is the actual representation of your skill. Win games to raise it, lose games to lower it.
The mathematical relation of mu and sigma is (mu) - k(sigma) where k is a constant assigned by the developers. This means that your skill is actually higher than the number you see, but the game does not give you the benefit of the doubt.
so people with high sigma go up more quickly than those with high mu this also works the other way, they can go down just as quickly.
for example you might have seen someone being a level 50 but they have only played like 150 games.. if you look you will also se eout of those 150 games they have only lost.. maybe 20.. this is because well either they are second accounters, really good, or have someone boosting them . and they have created a high Sigma, allowing them to boost up fast. When you play with a booster you get opponenets who are 10 to 20 levels higher than you so when you win against them you gain more skill points ( these are different from XP). the more skill points you gain from a match the more likely you are to go up one or more levels. Like if i played with you.. on doubles and we won .. seeing as how i would bring in Brigs, you could potentionally go up to a 31. But that is also based on your individual mu and sigma.
I think the reason you are not going up is becuase you have played ton of game and lost a ton of them as well. .Each playlist has a seperate tru skill. Like for instance it is harder to go up on team slayer and doubles becuase you have other people helping you win. where as you go up faster in lone wolves becuase it is based on individual skill. For example I was stuck on a 38 in Team Dubs and Slayer but i was only a 12 in Lonewolves so i played a few games and was ranking up two and three at a time. so i played 21 games and went up 26 levels.. after acheive a 38 i went up slower.. like once every two to three games
then i started getting matched up against 43's like there was me a 38 four 43'a and one 41 and I went straight up to a 40, becuase.. well they were garbage and I was playing well.
hopefully that helps. but remember, you only get the win if you are in the top 49%.
also, as of right now stats do very little to the ranking system. the only relation i have seen is you K/d ratio. becuase I once lost to 4 brigs in TS but I had a positive kill/death ratio and I ranked up one level.
Good luck. maybe ill run in to you..
