Grab a couple worlds, make repair bays, and turtle up as best you can. If your allies are in a really secure position, they should be able to feed you to keep you alive, or at least make you a tremendously costly pain to kill. Sometimes you will still die, but the point is to hold out long enough that your allies gain the upper hand. Basically, you die, but 2 of your opponents die to your allies.
If, however, your allies suck....then you are probably dead. But if they sucked, this allows you to move on to the next game where you don't have sucky allies, so it is a blessing in disguise.