Some people come to college and spend four years in a chemistry lab. Others put in incredible amounts of time producing a daily newspaper, or playing pinball machines. Quite a few, in colleges across the country, study, at night and spend their days ramming each other, passing a football, and getting their faces kicked in. Some of them don't even get paid for it.

Why do they do it? The lure, according to "Saturday's Hero," is a certain peculiar blend of cash, glory, and education. Heroes at Jackson U. do get paid, just enough to make amateurs in the audience restless, but it's obvious that they are being had. An underpriced, unreflective lot who do their jobs without self-dramatization, the players earn considerable respect and sympathy in the course of the picture, and the football scenes are authentic and very exciting. But always before the gridiron can begin to assume the romance or tragedy of, say, a bull-ring, the camera turns to the poisonous growths on the sidelines: the coach with the one-track mind and the rich, prestige-hungry alumnus who acts as "benefactor" to the deserving poor.

Years of slugging away at the boxing racket have taught moviemakers how to put across this kind of message with less hokum than any other. They have learned how to roughen up a slick exterior, how to use documentary techniques to set up scenes of tough, unglamorized action. The camera moves fast, nervously picking out detail: a monstrous fullback sauntering innocently away from an opponent he has just maimed; the ground rushing up toward a runner who has been blocked once too often; a scattering of hired athletes at a fraternity dance, each as distinct from the eager fraters as if he were standing under a glass bell-jar.

John Derek, as star halfback, overcomes a pretty-boy appearance with a straightforward though inarticulate performance; the others, nearly all perfectly cast, play their positions efficiently and unobtrusively. With its unsubtle emphasis and reliance on types, "Saturday's Hero" is obviously loaded, but it is just as obviously pointed in the right direction.