You would not know by looking at Luther Lassiter's hands that he can perform magic tricks with a cue stick.

They are small hands, with stiff, inflexible-looking fingers. And the hands dont just move; they fly about in swift, jerking movements that give the impression of a bad case of nerves rather than evidence of a God-given talent.

The hands seem separate from the ruddy-faced man with the halo of crisp, white hair. It is as if he is fighting to bring them under his control.

The hands stroke chalk on the custom-made, birdseye maple cue stick, and Lassiter bends over the table to sight his shot. For a second, those trembling hands are still. Then they blur with the wift thrust of the stick and plooock! Into a pocket goes one brightly colored ball after another until, bye-bye, nine ball.

The 58-year-old bachelor from Elizabeth City, N.C., is in Washington this week for the 1977 World Series of Pool at the Jack & Jill Cue Club in Arlington. The round-robin tournament with Irving Crane, Peter Margo, Steve Mizerak and Lassiter begins tonight at 8 p.m., with the finals on Sunday.

"Pool is the toughest sport in the world," claims Lassiter who has been at it for what he calls "45 years of misbehavior." "The only game that even comes close to pool is marble," he says.

Lassiter was talking about the tension quotient, of course. "There is that awful helpless feeling you have when you break and then have to sit and watch your opponent clean the table," he said with a chuckle that seemed to contradict a bad memory.

Lassiter is a cheerful man with a one-liner sense of humor that is only partially obsured by a chewy Southern accent. He looks calm and in control now, but there was a time when he let the variants of pool get to him. In his younger days, he was host to an ulcer of such dimensions that part of this stomach had to be removed with the offending spot.

He conquered his nerves and the ulcer and went on to become world champion four times, national open champion and three times the World's all-round pocket-billiard champion. He uses gimmicks to ease the tension now. He switches from coffee to hot chocolate when he's in training. "Coffee is terrible for your nerves," he says. He pops candy drops in his mouth as a substitute transquilizer. And he closes his eyes while his opponent is shooting to avoid distractions.

"People just don't understand pool that well. It's not like an exhibition of opera or violin where you can make mistakes and no one knows about it." His blue eyes crinkle as he describes the embarrassment of missing. "You make one little mistake in pool and everyone knows about it."

"Nobody can teach pool. Oh, the good players all watch each other to pick up little teeny things.But you're born with it. I took it up when I was 13 and by the time I was 17, I could beat anybody in the world in nine ball. That's my natural game."

Lassiter now practices only when he is in training for a tournament or an exhibition. "In my young days, I would spend 10 hours a day, seven days a week at it," he said. He has a custom-made table with smaller pockets that sharpen his aim, but he sometimes goes three or four months without shooting pool.

"I like to practice shooting pistols, rifles and slingshots - things like that," he says. "And I spend a lot of time sitting on the curb contemplating life sliding by me. But pool is a mind-over-matter thing. You have to think it through. You need strong legs and that's why I ride a bicycle. And stamina; you have to have stamina. Eyes are important. You need quick reastions and food spatial perception.

He grinned as a signal that a joke was coming, " You can't eat and play pool at the same time," he said. "It breaks your train of thought."

Lassiter thinks the natural progression for a sport that attracts more than 20 million participants a year is television. "With the camera mounted over the table, you would be able to see everything," he said. "Not like golf, where everything is spread out and you can't see a thing."

Meanwhile, he is ready to take on the challengers out in Arlington. The stubby-fingered hands take over. They unzip the cue case and assemble the beautifully polished maple stick that has been sanded an untold number of times and carefully rubbed with tung oil. The hands flutter and fiddle with the stick; it is a prize. "A man would rather lend his wife than his cue stick," Lassiter jokes.

The balls are racked up and Lassiter walks nervously around the table after the break. Nine shots later, the table is clear and the hands are momentarily stil. "It's just when something you do well gets the public eye, well, it just grabs you your whole life."