why wont i skill up on halo 3?

[guba2giba -OMAR =)]

if im not mistaking, the only games your skill goes up are on the ranked matches.
so here are my ranks on them:

lone wolves- 33(was a 34 but went down one)
team slayer- 19
team objective- 9
team tactical - 6
team doubles - 16
team control - 3
and team hardcore- 3

my total skill is 34
i keep on playing ranked matches and my skill wont go up, only the rank goes up
my exp is about 450
WHY WONT I SKILL UP?

 

[kkesle]

usually the way you skill up is playing on xbox live.but if you leave a match they penalize you and it takes longer to skill up