Every time he looks up, which is a lot, Alvin Garrett sees a world of tall people who think tallness is next to godliness. They gave his running back job to a guy 6-foot-5 in college, and so Garrett went out to wide receiver, where he became the MVP on a national championship team. And Saturday, when giants wrestled at RFK, how tall was the hero in the Redskins' first playoff victory in a decade?

"I'm 5-7," Alvin Garrett said.

They call him "Smurf," because he's the right size to hang on your rear view mirror. He's taller than his shadow at noon, but not by much. "They hoo-rah me all the time," Garrett said. "Like, they sing, 'Short people don't have no fun.' "

All this Garrett reported with a tolerant smile, because he knows, as all short people know, that the air is thinner the higher up you go and so tall people don't get as much oxygen to the brain, which explains why Too Tall Jones thought he could box.

Besides, forget the song. Alvin Garrett is having more fun now than any short person since Paul Williams danced with Raquel Welch. And being short has nothing to do with it. Short tells you nothing about mean, and mean is what this little Texan is. Look up mean in the dictionary, and there's his picture: Alvin Lynn Garrett, 26, Mineral Wells, Tex., out of Angelo State College, 185 pounds of muscle, tougher than a chuck wagon steak.

Before he was a hero, Garrett was an NFL kamikaze. You've watched the 11 defensive team guys race downfield on a kickoff. You've seen how they plow head-on into the offensive team's blockers. You've said, "You're a better man than I, Gunga Din."

Until Saturday, anyway, Garrett made his living racing under kickoffs and punts. He'd hurl his mighty body against the mastodons. He'd knock down blockers, he'd fly into the ball carrier.

"On those things, Alvin is a human spear," Coach Joe Gibbs said. "He's looking to kill guys. He's so tough. Hey, he is a player." The coach put a clenched-teeth spin on those sentences, raising an eyebrow to suggest that here is one little guy you want with you when you run into long-coated cowboys in a dusty American Express saloon. Legend insists, although Garrett demurs modestly, that being 5-7 never kept him out of trouble with tall folks who get beered up and say, to pick a sentence out of the air, "Chase any parked cars today, Shortie?"

History says there's a long story in this short man.

Twice in three years, the NFL told Alvin Garrett it didn't need him.

San Diego cut him in training camp, 1979.

The Giants cut him 10 weeks into the 1981 season.

When you're 5-7 and been fired twice, your professional football future isn't likely to include three touchdown catches in a playoff game for a team headed for the Super Bowl. Nor is it likely you will catch three more balls, giving you as many receptions as you made in your whole previous career. Least likely is that a former director of the CIA will see your 5-7 act and say to one of the country's wealthiest men, "Let's trade Art Monk."

That line was a joke, because Richard Helms knows Monk's value is limitless, but he said it Saturday to Jack Kent Cooke, the Redskins' owner, as a way of giving full praise to Garrett for his sensational work.

Because Monk is on crutches and because Virgil Seay has a bad thigh, Garrett started Saturday at wide receiver. Before you knew it, he ran a "fade" pattern to the corner of the end zone, looking up for Joe Theismann's pass falling over the defender's head.

Almost casually, it seemed, Garrett caught the ball-chest high. Here is a regular football midget, twice fired, with one catch in two seasons for the Redskins, and he looked casual making his first touchdown catch.

"I didn't know whether to jump or not," Garrett said yesterday, recreating the play. "I didn't know if the ball would make it over the guy's head or not. So I just waited on it. It was a good pass from Joe, right there, and I could see it all the way.

"In the end zone, I tried to keep myself calm and not get overexcited because there were still three quarters to play."

After his third touchdown catch, though, with victory assured, Alvin Garrett and his buddies from the "Fun Bunch" gathered in the end zone for a five-man, gather-in-a-circle, sky-high high-five celebration.

"This must be my day," is what Garrett remembers thinking at that moment.

The Chargers drafted him in the ninth round in '79 (on the advice of an assistant coach, Joe Gibbs), but cut him after a shoulder injury. The Giants signed him the next season and he returned kicks for a year and a half before they released him to make room for a running back.

"I never got discouraged," Garrett said, "because I thought all I needed was one chance and I could make it."

"As soon as we saw him on the waiver wire, we picked him up," said Gibbs. That was in '81. Two games later, he broke an arm on a tackle. Not to worry. Broken arm, broken ribs, sprained ankles. He's had them all. He keeps coming back. Only three weeks ago, he was on crutches with an ankle.

The hero's day Saturday left Garrett with one puzzlement.

"It's fun, really," he said of his dirty work on the kicking teams. "I like contact and I like hitting somebody. Hitting a person, getting your kayo is--I like that more than . . . "

More than touchdowns?

"Touchdowns are nice," he said, "but there's something about kayos. I like them a lot."

He smiled, ever so sweetly.