[Suicide Junkie]

The all-or-nothing effect is largely brought on by shields.
Shields are the essence of all-or-nothing, since they regenerate fully after each combat.

You would probably be very interested in the B5 mod style of defenses, where it is all about armor.
Not perfect armor, either; shots will skip past your armor once it starts getting thin.

Since the defenses are mostly armor, every shot will do more or less permanent damage, and even your victorious fleet will have serious repairs to complete before pressing on to the next combat.