 Al Pacino (qv) and Paul Guilfoyle (II) (qv) studied and examined  the play for four years before they decided to make a film of it.  When they finally decided to film it they spent four months  rehearsing before it was finally shot. They approached the  production of the film as if they were staging a play and wanted to  avoid making it look too much like a film. Pacino deleted any shots  looked too cinematic for his taste.