Hamm has placed himself right at the center of this world. In fact, when he is not sure that Clov has put his wheelchair exactly in the center of the room, he throws a tantrum. This brings up an important point: how can a character as totally helpless as Hamm be the protagonist? How exactly is he planning on, say, moving the action forward? (Hint: He's not. That's the point.) Hamm is the protagonist because he makes himself the protagonist, and he bullies everyone else around him. In a play that frequently on the brink of ending, Hamm is the protagonist because he has the strongest desire to prolong the action. Clov is ready for things to end, but Hamm isn't quite sure.