As several hundred scouts, personnel people and coaches from the 32 NFL teams focus on the practice field at this week's Senior Bowl, the goal is to formulate some type of impression of every prospect.
Some positions are easier to evaluate than others. The Senior Bowl is the first step, and will be followed by endless study of film and multiple spring workouts (including the Scouting Combine in Indianapolis in February).
Even the paid professionals have positions they struggle to evaluate. I think most would agree that the defensive back position is the toughest. I've always thought offensive linemen were the easiest players to evaluate.