Whether through improvisation or design, strategy has played a pivotal role in many major fights. Sugar Ray Leonard's decision to slug it out with Roberto Duran in their first fight was disastrous. Muhammad Ali's rope-a-dope tactic in his title fight against the thunderous yet ponderous George Foreman in Zaire was brilliant.

So it is not surprising that handlers for Eddie Mustafa Muhammad and Michael Spinks, the challenger and champion in Friday's light heavyweight title fight at the D.C. Armory, say they will not talk about such a crucial subject.

"I ain't givin' aid and comfort to the enemy," said Eddie Futch, Spinks' primary corner man.

And yet, there is little substitute for skill, experience and training. Although football allows time and context for computer-honed plans, boxers lose and win with instantaneous, instinctive decisions.

The ability to shoot the right over the left jab, to slip the jab and pound the body are developed through repetition. The results accompanying the slightest mistakes must be behaviorally imprinted: Lower the hands and feel the blood trickle down the jaw line. Blink and feel the back flat against the canvas.

For all the staring and spying, every boxer knows his skills and the skills of his opponent. But still the games and the plans continue as everyone seeks an edge. After losing his World Boxing Association title to Spinks in a 15-round decision two years ago, Muhammad is trying to set up all sorts of tactical screens--physical and psychological.

On the night before their last fight, Muhammad had to spend hours in a steambath burning off weight to make the 175-pound limit. Although he is by no means wiry, Muhammad looks trimmer for this fight.

"I lost last time because I wasn't in shape," he said after his workout at a Hyattsville gym yesterday. "Did I look good today? You tell me. Did I?"

All heads, of course, nodded assent. The truth is Muhammad may look slim but he is not boxing brilliantly in his brief sparring sessions. Rarely does any fighter go all out in his workouts for very long. More often the fighter works on one or two specific tactics against "ghosts" of the upcoming opponent. Muhammad is making a concerted effort to pick off the sort of stiff jabs and overhand rights so characteristic of the champion.

Nevertheless, the contrast between the two fighters in sparring sessions is sharp and does not bode well for the challenger. Spinks looks sharp, his punches are powerful and pure. Muhammad is inconsistent.

Muhammad must get inside of Spinks' longer reach. Like Joe Frazier against Muhammad Ali, he must cut off the ring.

"The mistake Eddie made in the last fight was that he fought straight-up," said trainer Wali Muhammad. "This time he has to keep his hands up and bob and weave.

"Eddie has slow feet. He's a stalker, not a dancer. You can't really change a fighter that much, though. I worked with Ali from 1963 until he finished, and I remember the Frazier people tried to teach Joe a right hand. But after a couple of rounds or so, he went back to what he knew--to the left hook. But Eddie's gonna win. He can tie a man up."

Muhammad not only thinks he can win this time, he also vows--as nearly every fighter does--to go "back to Brownsville" (his neighborhood in Brooklyn) if he gets thumbed as he claims he did last time.

"If he does it again, I'll thumb him, I'll knee him, I'll stomp him in the face," Muhammad said angrily.

Muhammad argues that he is hungrier. And to look at Spinks' training digs at the L'Enfant Plaza Hotel, there is no reason to doubt him. It is only when Spinks actually goes to work that the thesis crumbles.

Spinks worked intelligently and hard yesterday. He purposefully had his sparring partners bully him against the ropes and try to get inside the jab. Time and again, Spinks bounced off the ropes with sharp combinations that must have made his mates feel as though there were better professions in the world than the one in which they were engaged.

Spinks is able to throw a left jab and follow immediately with a left hook immediately after, an extremely difficult maneuver. His skills are sure. Although his division is weak, he is a worthy champion and must be considered a favorite to retain his title.

"Michael will do what it takes to beat this guy," Futch said. "Michael usually boxes in an orthodox manner, moving to the left and jabbing. But against (Dwight) Braxton he moved the other way to avoid the powerful left hook, and that worked, too. So it all depends on Mustafa."

What of Muhammad's charges of dirty fighting?

"He's preparing his alibi in advance," Futch said.