On stage your job as actor is to present and show the story by your behavior, body language, and vocal work. In film, you mustn't. You just have to be. You are...and it's mostly intuitive. The amount of characterization you do is very minimal. In fact, you try not to act at all. It's actually better that way, and it's taken me years to learn that.
(Hal Holbrook, quoted on the website ClassicSciFi.com
A veteran of stage, screen, and television, Holbrook has won numerous awards for his stage work and television performances. According to his quote above, Holbrook's minimalist acting style in films seems very much in line with Eastwood's.
Do you see evidence of this minimalist acting style in Holbrook's performance as Lieutenant Briggs? Is he believable in all aspects of the role? What do you like about his performance? What about his performance, if anything, do you dislike?