With the likely hypothesis that the degree to which a football player is physically suited to his position will determine his value as a player, we attempted to describe the characteristics of a given player and position and, from that, to determine the characteristics that make up a first class player in that position. Over a 4-year period 167 football players were examined at the National Athletic Health Institute, Inglewood, California, and grouped according to playing position and class. Position groups were: 1, linemen; 2, linebackers and tight ends; 3, running backs, quarterbacks and kickers; and 4, wide receivers and defensive backs. Classes were: I, rookies (nonstarters); II, veterans (nonstarters); and III, starters (veterans and an occasional rookie). Testing was in two phases, body characteristics and direct measurement of body function. All testing was done in connection with the preseason physical exam. Significant differences were found when data were analyzed by position. Position 1 players were taller, heavier, and had a higher percentage of body fat than players at other positions. These values decreased from Position 1 to Position 4. In terms of cardiovascular fitness the opposite trend was seen. Strength measures were also specific to given position groups. While few differences were seen when data were analyzed by class, one interesting finding was that Class III players (starters) were not only the oldest, but also had the highest level of cardiovascular fitness. Our conclusion is that while size, strength, and endurance are obvious advantages for the successful regular player, there is an unmeasurable quality reflected in the playing ability of the veteran player that is not easily identified in the beginning player.