Sadly, I think I'm only on the third or so ranking up you can get. I only am able to play on xbox live once every two weeks or so, so understandably, I suck, and still haven't even managed to make it all the way through the campaign yet.
I'm a pretty cautious player, and although I don't get a lot of kills, I don't die often either, so I'm not dragging the team down into losing. They still blame me though, cause their levels are higher due to logging more time, even if they went negative ten or fifteen.