Note: in no equilibrium is there any fight
Note: there is an equilibrium in which either player concedes first, regardless of the sizes of the valuations.
Note: equilibria are asymmetric, even when v1 = v2, in which case the game is symmetric.
E.g. could be a stable social norm that the current owner of the object concedes immediately; or that the challenger does so.
Single population case: only symmetric equilibria are relevant,
and there are none!