When mousing over a pirate shipyard with a small group of missile ships, the battle prediction was that I would incur a total loss and inflict moderate casualties. So I bombarded the shipyard down to low health, but it still gave the same prediction. I then outright attacked the shipyard, and destroyed it without losing a single ship. It appears that either it doesn't predict based on remaining health, or there is an error predicting after missile bombardments.
