The `Safe House` actor - who also directs and produces films, and has script approval - admits he is a "logic monster" and has to run through his parts with his movie colleagues before he is happy with them.
He said: "Nine times out of nine the script is not there, to my liking. And I`m a logic monster. If things don`t make sense, I gotta make sense out of them, and you get into the process.
Denzel has won two Oscars during his career, and he admits it may have made those who vote at the Academy Awards more aware of what other African-American actors were doing in their careers.
He told The Observer: "You have to have a part to play, first, that`s the bottom line.
"You don`t get nominated unless you have a great role to play and you interpret the role well. So maybe it shifted voters` attention to what certain African-Americans were doing. What Jamie Foxx did in Ray was phenomenal, it couldn`t be denied.
"I think Forest winning was a bit more of a surprise. Jamie was almost a phenomenon - he was Ray. The fact that I`d won a couple of years earlier, maybe that did help for white voters to say, `Hey, look at Jamie Foxx over here,` when they may not have prior to that. I don`t know. But maybe, maybe."