How can you tell really atrocious acting versus an actor chewing the scenery or hamming it up?

Any specific definitions or examples from films or series that depict this? It's always striking to me when watching a film and a particular performance is distracting but not so sure whether it's the case of the actor doing a poor job or hammy it up. Is this a common confusion with bigger stars than unknown in that bigger stars may give far less of an effort and their acting is all over the place in a scene or film?

Has there been any notable performances that have been nominated for prestige awards despite being over the top or seen as bad acting by some?

To Download Latest Movies - CLICK HERE