FATSO Football When Men Were Really Men By Arthur J. Donovan Jr. and Bob Drury Morrow. 228 pp. $15.95

Art Donovan is an exceedingly large fellow who played football for the Baltimore Colts in the glory days of that now-departed franchise and who probably would have vanished into obscurity long since except that he is also an exceedingly amusing fellow. It's been known around Baltimore for years that he tells war stories from his football days with gusto; more recently he has told them to national audiences on David Letterman's television show, with the unsurprising consequence that he has developed something of a following.

These days the first thing that comes after a following is a book, so here we have "Fatso: Football When Men Were Really Men," yet another entry in the as-told-to sports-book market. These books sink or swim not on their literary merit, of which none has ever had much, but on the personalities of the athletes whose autobiographies they ostensibly are. In the case of Art Donovan, the personality is as commanding as the man himself, with the happy result that "Fatso," for all its artlessness, is both entertaining and charming.

Donovan describes the book as "a fond remembrance of the way football used to be played, and the guys who used to play it," and the description is accurate. Though he claims he is not "spouting off about the 'good old days,' " he leaves no doubt that he considers football as now played in the National Football League to be vastly inferior to the game he played in the 1950s with the likes of John Unitas, Gino Marchetti and Don Shula. Misty-eyed, he reminisces:

" ... the NFL was a rough trade in those days. Despite all the moaning and gnashing of teeth over violence in the NFL over the past few years, I can safely say that anyone who didn't watch us play hasn't seen true violence in sports. In a way, I kind of miss it."

That's easy enough to say, of course, when you stand 6 feet 2 inches tall and weigh more than 300 pounds, as does the stately Donovan; football must be loads of fun for someone who need only lean on an opposing player to render him immobile. But for all his bulk Donovan was a gifted athlete -- he was strong as well as big, and surprisingly quick footed -- who made himself into a player of sufficient quality to be voted into the Pro Football Hall of Fame in 1968, six years after his retirement.

The road to the Hall of Fame was not exactly smooth, though Donovan got off to a good start: He was born into a happy Irish-American family in the Bronx, and grew up in a rough but close neighborhood where he learned not merely self-defense but also the subtler skills of friendship and loyalty. He went to Notre Dame, where he was unhappy; to the Marines, who shipped him to Okinawa; and at last to Boston College, where "I lived the life of Riley." Of college he says:

"Listen, let's be frank. I went to college to learn how to play football. I got an education, a good Jesuit education. You know, morality and philosophy and everything else. But everyone on both sides of the teacher's desk knew the score ... I went to class for four years and graduated and, yes, I did learn things, quite often through osmosis. I wonder how many kids at today's football factories can say that."

From college Donovan went to Baltimore, where he overcame his own doubts and made the Colts -- a dreadful team that soon folded but upon being revived a couple of years later matured into a football legend. Donovan loved being a Colt, loved being in Baltimore, and when he found his future wife, he loved her too: "... from the moment I met Dottie it was love at first sight. She had it all: big boobs, she didn't smoke, and she was Catholic." Who could ask for anything more?

Donovan writes about his life on and off the playing field with infectious enthusiasm; he loves to tell tales about boozy ballplayers and flirtatious floozies and other such football folk, and the tales are fun to read. But he is nobody's fool. He believes, correctly, that "the one thing that has probably remained constant throughout the football decades is management's sense of football players as no more than pieces of flesh," and he is therefore entirely unsentimental about the game.

His days in it ended in 1962, when he was 37. His retirement was involuntary, but he made the most of it. He stayed in Baltimore, running a small chain of liquor stores and, with his wife's collaboration, a country club. He is a prosperous citizen of his adopted city, and a hugely popular one. It doesn't happen often, but sometimes good guys do finish first.