Consider for a moment the great American vision of what happens at halftime in any given locker room:

The coach storms in, smoke wafting alternately from each nostril and both ears. As his players cringe in fear and awe, he slams a table, kicks a locker, and dresses each man down in turn.

Then, rage vented, the savage beast is transformed instantly into a brilliant psychologist, motivator and strategist, Gen. Patton manipulating an army of jocks. The maneuvers he etches in chalk would delight the Joint Chiefs of Staff. He craftly reassembles and massages the egos he has shattered, molding them into a team consciousness, and sends his troops back into the game with a pep talk worthy of Elmer Gantry.

That is what the casual fan is conditioned to expect from old movies and legends that fire the imagination. Pat O'Brien on a soapbox, exhorting his charges to "win one for the Gipper." Percy Haughton strangling a bulldog to demonstrate to his Harvard lads what must be done to Yale.

Because the fan never sees inside a locker room at the half - even in an age when television has intruded on virtually every other aspect of our games - the myth lives on.

"I think the guy in the stands still thinks that Knute Rockne is alive and well," says Dick Motta, who is in his ninth year as a National Basketball Association coach, his first with the Bullets. "If he were to come into the locker room at halftime of a typical game, he'd probably be terribly disappointed."

What does go on behind those closed doors varies greatly, depending on the level of competition, the importance and pattern of a particular game, and the personalities of the coach and players involved.

Locker-denting and game-changing tactical revelations are rare. Neither, as the less romantic assume, do the players merely sit around and suck oranges.

Most coaches would agree with Les Lombardi, who directs the boys' varsity at Winston Churchill High School in Potomac, when he says there are four things he tries to accomplish at halftime: 1) refresh his players, 2) go over the game from his point of view, analyzing what is happeing and what strategic adjustments must be made, 3) review the foul situation and other pertinent information, and 4) make a "good mental transition to the second half, so we go back up on the floor on the right note."

Last weekend the home team's half-time session at three local basketball games - Churchill vs. Bethesda - Chevy Chase High School, Georgetown University vs. Seton Hall, and the Bullets vs. Detroit - were examined to determine what really goes on during intermission.

The Bullets were ahead, 55-51, at halftime of their eventual 119-108 victory over the Pistons. They filed into their dressing room at the Capital Centre quietly and sat in their individual needs. Most went to a refrigerator and grabbed cans of soda. Several applied ice packs to wounds or fiddled with tape, pads, uniforms.

Motta chatted with his assistant coach, Bernie Bickerstaff, in his office, which adjoins the dressing room. After several minutes he walked through the open door, got himself a soda, and said nothing for perhaps two minutes. Finally he took an index card from the pocket of his sport coat and started reciting how many fouls each player had.

He went to the blackboard and printed two words: "TRIAGLE - LANIER." He drew a diagram of the left side of the forecourt and recalled in verbal shorthand a problem the team had worked on in practice, preventing the Pistons' massive center, Bob Lanier, from taking lob passes and getting free inside, Motta calmly reminded the squad how he wanted to defense the big man. Bullet center Wes Unseld offered an observation on the subject. That ended the formal discussion of strategy.

Kevin Grevey, who had sprained an ankle after playing a strong first four minutes, walked in gingerly from the training room and pulled a sneaker over a bulging sock.

"How' he?: Motta asked trainer John Lally.

No swelling. I taped him up."

Let him warm up?"

"Yeh," said Lally. (Grevey played most of the second half.)

For most of the remainder of half-time, the team watched videotape on a color TV monitor. Bickerstaff and the players were more loquacious than Motta. The atmosphere was more like that of a routine audio-visual presentation in a corporate board room than anything out of 'The Knute Rockne Story."

Finally Motta announced, "Five-and-a-half minutes. We're up by four, our ball. Let's go." The players clasped hands in the middle of the room and trotted back out on the floor.

"That was pretty typical," Motta said afterwards. "I probably talk more now than I will in another year or two, when the team and I are more familiar with each other. I like half-time to be primarily a rest."

Motta says he has used essentially the same approach to halftime - a reflection of his organized, methodical, open style of coaching - at all levels, from junior high up, but that a low-key approach is especially necessary in the pros. "You can't use psychological tricks on guys who play 82 games a season," he says. "You just don't have enough tricks. The motivation has to come from within."

John Thompson, who was back-up center to Bill Russell when Red Auerback was coaching the Boston Celtics, and became the head coach at Georgetown in 1972 after six seasons at St. Anthony's High, thinks there is "a tremendous difference in the approach a coach must take" in high school, college, and the NBA.

"A high school kid is still impressionable. He's enthusiastic, grasping for knowledge, easy to indoctrinate and willing to learn," says Thompson. "College kids have been around, their bank of knowledge is a lot deeper. They have some ideas about how things should be done. You have to be shrewder and tell them something more than just emotional things, cliches. A professional, even more so. The motivational factor is the dollar. He thinks he knows everything. He's sure he knows more than the coach.

"I think motivation is overrated in coaching," adds Thompson. "Especially in college or professional basketball, the responsibility for motivation is on the players. The goals are built in today. It's not like the 1920s, when a bunch of kids came out of the dormitoary to play for fun and recreation."

The high school halftime, though still distant, is at least closer to those delightful fantasies of what the locker room scene shoudl be. When Churchill played Bethesda-Chevy Chase, with the Montgomery AA League lead at stake, the home dressing room was decorated with slogans and banners.

Churchill by 16 in the first half, but their play became ragged in the last three minutes and saw the lead shrink to 36-29 when the players headed for the locker room. The atmosphere was highly charged, anxious, decidedly rah-rah and old school spirit compared to the cool professionalism of the Bullet locker room.

After about two minutes, coach Les Lombardi walked in, minus the jacket of his dark blue suit. He crouched in the center of thr room. "OK, let's sit down, fellas," he said.

Lombardi then called in his assistant, George Thompson, to diagram and explain a play that B-CC had been using successfully.

"They did the exact same thing in the jayvee game," said Thompson, who outlined a simple play in which a man set a pick at the top of the key, then dived down the lane. "The man is coming off the post and running a figure eight," he said. "We're not paying attention to him. They're setting one pick away from the ball, that man is rolling around and getting free underneath."

Thompson explained how to defend against the move, then left the room. Lombardi touched on several other tactical points, leading a responsive dialogue: "What are we doing right?

What do we have to do to stop them inside?. . . Who do we want to get in foul trouble?"

Thompson returned and read down the stat chart. Lombardi said, "On the next out-of-bounds play, we'll go with No. 1. We haven't showed them that yet." Then he went into his second-half psyche, his voice relatively soft, but occasionally rising to a pitch calculated for effect.

"Remember what we said last week about spurts? . . . People will believe we're for real if we blow these guys out!"

The team joined hands, let out a whoop, and ran out for the second half. They won, 82-60.

"It's important at the half to review things you did in practice, to stir up the memory," Lombardi said. "I try staying away from the X's and O's as much as spossible. If we've scouted a team well, we don't need that. I also like to play as many kids as possible, especially in the first half, so that you re-talking to everybody.That's important, especially in high school."

Lombardi believes in letting his players keep the first couple of minutes of halftime for "team communication and constructive criticism among themselves." Georgetown's Thompson agrees: "They get a chance to talk to one another and get a little bit of their fustrations out. A guy may be mad about his play, or somebody else's, and this gives them a chance for communication that's very important.

"A lot of it is based on the coach's temperament, too," says Thompson. I'm an emotional person. Therefore, before I go into the locker room, I'll always take three or four minutes outside to collect my thoughts. I think what I'm going to say, what strategic adjustments I want to discuss, who I've got to push a little bit and who I've got to console.

"If I went into the locker room right off the floor, it would be a spontaneous thing and I might say or do somthing I'd be sorry for later."

Thompson felt that allowing a reporter to sit in on his halftime session would infringe on his players' privacy, but he talked about his approach after Georgetown lost a seven-point half-time lead and bowed to Seton Hall, 94-87, its first loss this season at McDonough Gym. He thinks that during intermission, a coach should do some strategic fine-tuning and aim at achieving a delicate emotional balance of eagerness and readiness.

"Basketball is a fast-moving, emotional game, and people's temperaments differ," he said. "Maybe when I was younger, I was too much of a madman at halftime. Now I tend to pick my spots to get excited. But you can also be too calm, too nice. Sometimes you've got to get your guys fired up.

"Like all coaches, I trust my instincts and feelings and respond accordingly to a particular set of circumstances at the half - how the team is playing, how individuals are playing the importance of the game, and so forth."

Thompson recalled his days as a Celtic under Auerbach, the winningest coach in NBA history. "Red wasn't as much of a bully as people thought. He projected the image of being a rough-and-gruff, kick-the-door-down type, but he was too smart for that. Red could handle men real well. He could make players adjust. He had levels of tone in his converstion, and he talked to the team and to individuals.

"Very few times, if ever, do I remember him dealing with the black-board in his talks. That kind of coaching he left to practice sessions. But he was very good at analyzing what an opponent was doing to hurt us, and getting guys to adjust and do what he wanted."

"One of the greatest halftime speeches I ever heard, the coach didn't open his mouth," remembers Thompson. "It was 1962-63, my junior year at Province College. We were down by 16 at the half to Dayton in Madison Square Garden. Joe Mullaney came in, sat down, and never said one word. He was that disgusted."

Did he scowl? Smile? Smirk?

"He didn't do nothing," said Thompson. "He just sat there, and so did we. We didn't dare do anything, the way were playing. Finally a guy came in and said, 'Providence back on the floor,' and we said, 'C'mon, let's go,' and went up and blew them out good. We turned it all around, won 13 games in a row and won the NIT that year."