Roy Scheider received his first Oscar nomination for portraying Detective Buddy 'Cloudy' Russo in The French Connection.
Despite this rather big limitation Scheider still makes Russo into a character, whom does seem like there is probably more to him but we only ever see him on the job. Scheider makes Russo into a very much normal man who does his job. Scheider always is quite natural whenever he is doing anything, and there is never a moment where Scheider acts as if Russo is doing something far out of the ordinary. With this Scheider establishes Russo's history has been long.
Scheider also is good in his distinct chemistry with Hackman as they play off each other in their scenes together. They have a particular dynamic the way they interrogate, and work together that shows their long history on working on cases. They work together perfectly as Hackman as Doyle is the more intuitive one, as well as hot headed one, against Scheider as Russo who acts as the more level headed and cool headed one who tries to keep Popeye sensible.
Although Russo is most certainly a limited part but Scheider makes more than the most it. He is realistic throughout and easily adds to the realistic tone of the film. Even though the character as written could have far too simple, but Scheider though still manages to make Russo into a realistic character. It is not the most complex part, but Scheider does his very best in the part to bring Cloudy Russo to life.