Fight or flight?

Hypothetical situation: say you've found yourself in an encounter with a captain where your chance of survival is very low. Do you fight and likely die, or do you run and live to fight another day?

On one hand, death is a great catalyst for the nemesis system. On the other, I don't like resigning myself to defeat when I have a survivable alternative.

Vague, I know. But how do you guys handle these situations? (Aside from being too good to die.)