Boxing has two great halves: tactics-technique and heart-soul.

When Sugar Ray Leonard enters the ring with Roberto Duran here on Tuesday, he will need to show great improvement in grasping the strategy of his brutal sport while losing none of the courage he proved when he first met Manos de Piedra in their maul in Montreal in June.

Perhaps the starkest view of the twofold tactical and emotional task before Leonard is painted by Ray Arcel, an old man who speaks so simply that he cons you into believing you're hearing a deathbed confession. But his words are resonant with decades of quiet observation.

Years ago, during the time when he brought 14 victims into the ring to meet Joe Louis, they called Arcel "The Meat Wagon."

"Between the time we left the dressing room and walked that last mile up the ring and they played the national anthem, a strange thing would happen to my fighters," recalls Arcel. "Did you ever see a tulip wilt? That's what happened to my men when they saw Louis. I had to carry smelling salts before the fight just to get them to stand up straight and look like an opponent.

"You can fool the world, but you can't fool yourself," says Arcel, who has handled 19 world champions in the last half century, including Barney Ross, Benny Leonard and now Roberto Duran. "When the great fighters meet, the outcome is always decided between the fighter's ears before the bell ever sounds.

"You know, in your heart and soul, if you can do the job. Sugar Ray Leonard knows he can't.

"He learned that in Montreal. Against Duran, he was a boy against a man. Only Leonard knows just how badly he was really beaten.

"I think Leonard could have been one of the greatest fighters of all time, if he had waited another year to fight Duran. Then, he might have been ready, might have mastered his craft. But Duran knew all the tricks and Leonard knew none. . . not the tricks of a real pro like Duran, who's had 75 fights.

"How much mental damage did Leonard suffer in Montreal?" Arcel asks. "It's only been six months. Only one thing has changed. Now, Leonard will walk into the ring knowing that he can't win. I think he'll wilt. That's a terrible shame. I like Leonard. But I'm afraid that after this fight he may quit and boxing will have lost a great talent."

The whole boxing world is saying that the Super Fight in the Superdome will be a vastly different battle in tactics and tempo, and, perhaps, in its final result. Enough people think so that Leonard, the challenger for the WBC welterweight crown, is actually the betting favorite.

"It will be exactly the same fight," disagrees Arcel. "Duran will not allow it to be otherwise."

If New Orleans recapitulates Montreal, with the French tang of old Montreal merely being transported to the Old Quarter, then, even Leonard admits, he will probably lose again. Already, the Leonard camp has its mea culpas and its rationalizatons down pat.

Leonard claims he started slowly and seemed intimidated for four rounds because the prefight hype distracted him. Trainer Janks Morton says the pro Duran crowd in Montreal was psychologically important: "The biggest thing is for us to turn this town and the crowd against Duran. It will bother him."

Manager Angelo Dundee says that referee Carlos Padilla was the villain since he let Duran conduct a brawling fight that inflicted as much pain with head, shoulders and elbows as with his famous hard hands. "They ought to make Duran wear a glove on his head," rails Dundee. "He committed every foul in the rule book."

For what good it does him, Leonard should not be overly distracted this time. And, he is sure to be the crowd favorite in the U.S. And in a slightly bigger ring, 484 square feet as opposed to 400 square feet, Leonard should be more maneuverable. And, finally, after all the carping, any ref who works this fight will probably inhibit Duran's style a bit.

Perhaps more important, Leonard is talking more reasonably before this fight, eschewing such silly statements as, "I'll not only beat Duran, I'll kill him," and, "I can trade punches with Duran. . . I'm stronger than he is."

"I did not use my skills at all in Montreal," says Leonard. "I never jabbed. I never moved. I never circled to my right. I never mixed up my styles. All we did was slug like hell for about 30 seconds of every round and spend the rest of the time wrestling on the ropes and clubbing each other. I wanted to prove that I could go toe to toe with Duran and take everything he had. I did. But it cost me my title.

"I'll always be repetitious (insistent) about fighting him that way. I don't regret it. I had something to prove to people. But, now, I have conquered my stubborness."

Is this merely post-mortum reasoning? Ten minutes after their first fight, Leonard was asked at a press conference why he never jabbed, why he never danced, why he never resembled his normal self. Leonard, his face a many colored fast-swelling misshapen mask of pain, said slowly, finally and, probably, honestly: "He wouldn't let me."

Now, of course, the tune has changed. "I have a big surprise for Duran. He will see many Sugar Ray Leonards this time, not just one who is fighting his kind of fight."

That sounds good, although it is exactly what Arcel would call fooling the world. Leonard talks eloquently about the changes in tactics that will stun Duran. He has noticed how Duran repeatedly bores forward, leaping into the fray behind an overhand right.

"I've learned to counter that by stepping to the right and throwing a right of my own, or I can step left and stop him with a left jab," he claims. "The way to avoid a truck isn't to keep going backwards. The truck just builds momentum. I have to move side to side, not in and out. That way I can change his rhythm and dictate to him. It's all here," says Leonard, tapping his head. You have to make the other man think like you. . . put him on your brain wave, It's like a country square dancer and a disco dancer in the ring together. You've got to get that interior rhythm going your way so you know where he's going to be."

It is perhaps boxing's oldest adage that when the leather flies, strategy goes out the window. "As soon as Duran hits Leonard," says Arcel, "he will fight just like he did in Montreal -- pinned against the ropes." Even the Leonard camp fears this. "Maybe Ray has too much damn courage," says lawyer Mike Trainer. "Everybody says he is a pretty boxer, but to me he's all fighter; hit him, and he'll hit you back. His instinct is always to trade his best shot with you.

This is not Leonard's most severe tactical problem. In Montreal, Leonard never found a style of fighting where he looked comfortable or superior.

When the fighters stalked each other, heads perhaps two to three feet apart -- the range at which Leonard, with his longer reach was supposed to have an advantage -- Leonard was at his least effective. In the entire fight, Leonard never landed a significant blow from long range. He seemed afraid to be aggressive, leary of Duran's vicious countering left hook. So Duran always took the initiative, bulling ahead scores of times behind that overhand right.

In close, with their heads touching or inches apart, Leonard was tough but tangled in a losing battle against Duran's short pumping arms and butting head. Duran was completely within Leonard's perimeters with Leonard only able to clamp Duran's arms, hooking them from the outside in countless clinches.

Only in that middle world between boxing and wrestling when their heads were perhaps a foot apart and both had decent leverage, did Leonard hold his own in both the 11th and 13th rounds. The pair battered each other in this range with equal excellence and valor.

It is during just such in-between fire fights of fury that Leonard has his best chance. That, is perhaps, why he has taunted Duran here, calling him ignorant and classless and too dirty to hold the crown. "I'm giving back to him what he's dished out to me," says Leonard.

Duran fights at the edge of control, on the brink of rage. Leonard must find a way to make Duran cross the line of good sense, forget his experienced mauling tactics and engage in a duel of megapunches at half a pace until one of them in unconscious.

If Montreal holds any lesson, Leonard cannot win either from the outside or the inside. How to tempt Duran repratedly into that dangerous middle ground of maximum-force knockout punches is a touchy tactical problem.

If Leonard cannot find a way to get Duran on his wavelength, get him engaged in those lethal exchanges of blurred combinations which are the Sugar-Man's hightest art, then he will have nothing to fall back on but the bludegeoning memories of Montreal And perhaps only Leonard himself knows how bleak those memories really age.