Had to look again and again during a game last night.
Late era, getting rid of those pesky (insert nation here).
My gunships were happily pounding a city into submission when suddenly . . .

All that was left was non-ground units, like bombers, fighters, destroyers and some battleships.
(Yes gunships can destroy aircraft in cities, one by one)

Checking my odds on attacking, the campaign suddenly took a turn toward the suicide attack!
25 vs 89
Same thing with my Mech Infantry.
The game was giving me the odds of my units attacking the Battleship
(ok, the exact numbers are probably off, but you get the idea)

At suicide odds displayed on the attack, the Mech Infantry simply rolled into town.

i'm reasonably sure non-ground units are destroyed by an attacking force if they're all that's left. so the odds are 100% in favour of even a warrior.

yes, but it was interesting that the suicide odds were displayed.

So it did the odds for the battleship even though you didn't need to take it out?

i guess that qualifies as a bug.

Even if the attacking Mech. Inf. was shown as having a strength reduced to 1 and the vastly-promoted ship showed 60, the combat odds ought to have shown 100% in favour of the M.I. - ships and planes in cities have no defence against land attacks and are destroyed when the city falls to such an attack. The original post mentioned "25 vs 89" : what actual combat odds were shown is not mentioned, but in my experience the displayed odds cannot be simply calculated from the strengths; other factors clearly enter into the arithmetic.