I've noticed this too. Idiots with no common sense, tossing gas cans into spitter goo or healing (with 60 health, i may add) while a hunter go to town on Coach two feet away from them. It amazes me how dumb kids can be. I usually check out my teammates achievements, as bad as that sounds. If they have left 4 dead one, or they have a majority of the achievements, i usually rely on them. Otherwise, I hop on over to the other team.