There are three acts in the play just like the three characters. The first is Aston and Davies's, the second, Mick and Davies's, the third, a complex interaction among the three. The time structure from the first to the second is almost continuous while there is a temporal rupture between the second and the third. This time-scheme is precisely the same as in Osborne's Look Back in Anger.
There is very little action; all of it occurs on the verbal level. The climactic structure is something that realists tend to make a lot of, but someone like Pinter who is well equipped with the tropes of magic-real, absurdist and sur-realist theatre would create and he does, a rather inconsistent, up and down and uneven structure of reality. In the first act, I think, the climax is still made a little physical and evental. The scuffle between Mick and Davies is a climax indeed. Mick's final line--"What's the game" is a perfect closing line as we look forward to the second act for answers. In the second act, the climax happens with Aston's long speech, which in itself has a whole Freytag triangle with all the stages from exposition to resolution in it. The speech is a climax in its content. It is a very rare back-story that we get in Pinter, sans all the particulars, however. The trope of madness is crucial to the dynamics of the play. The third and final act of the play has a sort of an anti-climactic point when after all the promises, Davies is stripped of his prospective role of being the caretaker by both the brothers with rather inexplicable and unfair arguments. Davies's return is like a resolution where the action is raised to another potential climax which closely falls down with Davies's pathetic little speech at the end.