I have an asymmetric view of what winning entails for both animals. For the bear, winning means killing and eating the bull. For the bull, winning means not getting eaten.

On balance, I think the bull is likely to survive this encounter, with both animals being injured.

Undisciplined

Stacker Saloon

saloon

My daughter tells me that she is talking about a polar bear, a polar bear would have no chance with a bull, unless they are in the bear's habitat, then the disadvantage would be the bull.  My curiosity thinks of a grizzly bear against a bull, it would be a very close fight, maybe I lean towards the bull.