To all the people who think they are rubbish..
NO YOU'RE NOT!
Against someone who is very smart when playing FPS games (not skilled, I don't think skill is involved in games) then you're always going to look rubbish.
I'm not a smart player and it shows when I'm up against smarter players, but even I get into lobbies where I do very well indeed. So don't knock yourself.
I've seen players with 20 percent accuracy but with a K/D less than mine, then I've seen the complete opporsite to that.. its not skill, its being smart and keeping a cool head.
So practice and learning little tricks, learning how maps play etc all improve your game.