THE TROUBLE with being addicted to reading about sports is not that it's a waste of time - at its best, sports literature is entertaining, provocative, revealing and surprising - but that you have to suffer through so much dreadful prose in order to come upon the occasional gem that makes it worthwhile. It averages out, I have found, to about one or two such gems a year, and 1977 has been no exception.

Sometimes I wonder why, having passed into a state of what is alleged to be maturity, I continue to read these things. I started reading sports books about 30 years ago, when I was a kid and a fan. Now I am not a kid and not much of a fan either, but I keep on reading them. In some measure, no doubt, it's a simple case of arrested adolescence; but there's more to it than that, for me and for the countless other people who continue to read sports pages and sports magazines and sports books long after they have creased to care who's on first or in first.

Perhaps, indeed, that is the very point: that after it no longer matters who won and who lost, one is in a sense freed to appreciate sport in its more complex and interesting dimensions. I'm not talking about "sport as a metaphor for society" and similar prattle by which some people try to give academic or literary legitimacy to their interest in sport. Rather, I mean the virtues intrinsic in the games we watch and play - their direct connection to our memories of childhood, their capacity to involve us in shared experience, their power to bring us to easy laughter and tears, their occupancy - at the highest professional levels - of a world only the most gifted are allowed to enter.

Roger Angell got directly to this last point several years ago when he described the "small attendant cloud" of sportswriters surrounding a young baseball star: "Every one of them was there to ask what is, in effect, the sportswriter's only question - the question that remains unanswerable, because it scratches at the mystery that will always separate the spectator from the athlete: 'How does it feel to be you?'" Why else do we read such ephemera as No Big Deal, by Mark Fidrych with Tom Clark (Lippincott, $8.95), and Even Big Guys Cry, By Alex Karras with Herb Gluck (Holt, Rinehart and Winston, $8.95)? Even though such books only rarely unlock even the smallest of mysteries, the fleeting contact they give us with these sporting heroes, and the illusion of intimacy they provide, permit us some satisfaction.

Similary, we delight in the work of George Plimpton because he grants us access to this world of the physically exalted on terms we can understand: he enters that world himself, as an amateur willing to test his limited skills against those of the champions. By setting himself against great athletes, he is able to help us understand precisely how great they are and to appreciate the distance between us and them all the more. As he did in the past with baseball players (Out of My League) and football stars (Paper Lion), he does now with such celebrated boxers as Archie Moore and Muhammad Ali in Shadow Box (Putnam, $9.95).

Boxing is at the center of another book that manages to combine intimacy with sports celebrities and rich sports humor. Ferdie Pacheco has been Ail's physician since the days when he was Cassius Clay, and he tells dozens of delicious stories about it all in Fight Doctor (Simon and Schuster, $8.95). Irreverence is an essential ingredient of sports humor, and Pacheco delivers it in generous quantities. Although the prose is something less than graceful, the book is so funny and preceptive that it is entirely valid on its own terms.

It is baseball, however, more than any other American sport that provides a rich literature. No doubt some bias is at work here: there is no game I would rather watch, no game I would rather read about. In fact, my love of baseball has sent me into some thickets of impossible prose in search of hidden pleasures. But at its best, writing about baseball capitalizes on the game's unique attributes: its singular American-ness, its blend of rural and urban characteristics, its careful balance of team and individual play, its extraordinary beauty, its link to the past.

That past lives in two delightful new books. One is a reissue of a 1972 "inside" look at baseball by the great pitcher, Christy Mathewson. It is call Pitching in a Pinch (Stein and Day, $10; paperback $3.95), it is written (with the help of a ghost) in the stilted sports lingo of the day, and it is utterly charming: among other things, it vividly demonstrates how little the great game has changed. There are similar virtues to be found in Baseball As I Have Known It (Coward, McCann & Geoghegan, $9.95), the autobiography of a man named Fred Lieb who is 89 years old and has been covering baseball since 1911; his memory is sharp, and when he starts telling stories about Eddie Collins and Honus Wagner the reader suddenly awakens to an awareness that this man's professional lifetime spans their day and that of Reggie Jackson and Tom Seaver.

But it is in the work of Roger Angell that all the possibilities baseball offers to the serious and gifted writer are most fully realized. This is not to say that Angell is soleman; to the contrary, he is terrifically funny and self-mocking. Unlike some of the young poets and other blithe spirits who have lately made a fashion out of being wildly, madly and precioulsy in love with baseball, Angell knows the game intimately and declines to attribute to it qualities it does not possess. Five Seasons (Simon and Schuster, $9.95) is an even better book than The Summer Game, and that is a compliment I never thought I would pay to any baseball book. It is a book that helps one understand why it is such a wonderful thing to love baseball, and a book that elevates sportswriting - not to mention sports-reading - to new heights. It is so far and away the gem of '77 that onecannot even talk about competition, for none exists.