Nearly two milleniums ago, Greek boxers first put on the cestus, a hand covering made from thongs of bull hide and studded with iron or brass nuggets; breathed, in the earlier words of Theocritus, "slaughter against each other," and fought to the death for the amusement of Roman sportsmen. The Cretans may have been the first people to make a more or less official sport of boxing; there is some evidence that boxing matches existed as early as 1500 B.C. in Crete. But it was the Greeks who raised it to a national sport, belaboring each other for hours--without rounds, with very little subtlety--beneath the blazing sun. And it was the Greeks, battling in the Roman arenas in the last century of the Empire, who added that touch of appalling finality to what had once been among the truest tests of an Olympian. All in all, boxing has never really recovered, and that's not as it should be.

If the wonder of baseball is that all those complex rules and measurements--three outs, 90 feet here, 60- feet-6-inches there--have worked so well for so long, the glory of boxing is its simplicity. There are critical ways in which one boxer may not hit another one, but they are few in number. The contest is between the athletes in the ring, more so than between the athletes and officials, and the tedious spectacles that so often accompany a book of sporting rules have no place in boxing. Boxers do not go to the foul stripe, and boxers and referees do not go jaw to jaw at ring center: "You hit him below the belt." "Did not!" "Did so!" That says something good and true for the sport, or should.

In consequence of boxing's simplicity, the vast supporting casts that cloud the primal issue in so many other sports are nowhere to be found in a boxing match. A Sugar Ray Robinson may have come into town with an immense entourage--voice coaches, dance instructors, hair- dressers and gofers; but when he got into the ring, Robinson, like all boxers, was alone. There are no heavily wired offensive coordinators in boxing, no defensive specialists with their endless clipboards; no one is flashing signals, calling plays from the sideline. A manager can yell "jab," "circle," "hook" from the corner; but if a boxer chooses to ignore him, he can't be yanked. There are no substitutions in boxing, no relief punchers. A boxer doesn't come out in an I-information, a wishbone, doesn't call audibles at the line. There is strategy, of course, but the pageantry of pain is rarely subsumed in the strategy. Boxers are in the ring to wear one another down, to hurt one another, to knock an opponent down or render him incapable of going on; and finally it is only the boxer--single-minded, breathing slaughter--who can do that.

Earl Weaver may look more like a fight manager than a baseball one, but if Weaver had taken up boxing instead of baseball, the world would note him less and remember him little. Boxing belongs to its competitors, just as boxers with the rarest exceptions belong to their sport. Beyond the ring, they have little economic viability: boxers do not endorse underwear; ex-boxers are good for official greeters, for bouncers and little else.

Yet for all its clarity, boxing has a capacity for surprise that few other sports can claim. "Rocky" could not have been made about a tennis player, and not only because Rocky's part of Philadelphia doesn't much cater to baselines and volleys. A Bjorn Borg, a John McEnroe will beat the 100th-ranked tennis player in the world 80 games out of every 100, and 100 matches out of every 100; but a boxer has his deus ex machina--a roundhouse right, an uppercut--his very own dream machine. If it rarely happens that a bad boxer beats a good one, the potential, the stuff of fantasy, is there nonetheless. The only fantasy that could carry the very bad Senators of the 1950s to the American League pennant lay in selling a soul to the devil, but club boxers like Rocky can dream. And so can their fans.

Tomorrow, undoubtedly, a significant number of people will pick up this paper, see news of the Ray Leonard-Thomas Hearns bout (superb athletes, they fight tonight for the undisputed welterweight championship of the world), and bemoan that mankind has not advanced far up from the apes, or out of the cestus. There will be--there must be--an air of appalling finality hanging over that fight as there is over any fight. Injuries may happen just as frequently in football, but in boxing they happen in stark relief: a head snaps back, a body slumps to the canvas, and not beneath a layer of armor. The secret thrill that those of us who watch the fight will get from that possibility is part of the ugly side of boxing; but we are likely, too, to see sport at its truest. The victory will not be the primarily internal one that jogging offers; it will not take place within a dense framework of rules. The winner will have no teammates to hug; no one but the loser will have shared in his agony. Instead the winner will know that on this one night against one other man--with horrible potentials swirling about him--he was the better. Something good should be said for that.