Bruce Sutter's normal pitch arrives about belt-high to a worm. But in the top of the ninth inning tonight, a split-finger fast ball from the Cardinals' omnipotent reliever came in shoulder-high to Milwaukee's Robin Yount. This was a felicitous turn of events, and a darned good thing, for St. Louis. It helped tie the World Series at a game each, and some folks saw signs tonight the Cardinals will win it all.

With Paul Molitor on with a single, the Brewers thought to work a hit-and-run play. Had Sutter thrown his customary dirt-brushing pitch, Yount might have hit it into right field. Had the pitch been in its usual place, the Cardinals' catcher, Darrell Porter, would have had a hard time digging it out and then throwing out the speeding Molitor.

But here came Sutter's freak pitch upstairs. Yount swung and missed. Porter, coming up to grab the ball, immediately relayed it to second base to cut down Molitor. Two hitters later, Sutter had saved the Cardinals' feathers from the fire of defeat again. St. Louis 5, Milwaukee 4.

Someone asked Porter why the hit-and-run pitch had been so abnormally high, and the catcher, smiling, said, "That was Bruce's overhand curve ball."

"Don't give away no secrets, now," Sutter called out.

There is no such thing as an overhand curve ball in Sutter's life. He comes to work with one tool: the split-finger fast ball. No one else can throw it. Practically no one can hit it. It is the baseball equivalent of Green Bay's Kramer-Thurston-Hornung sweep, of Kareem Abdul-Jabbar's sky hook, of Sugar Ray Leonard's right.

No secrets. No deception. No guile. Here it is, wise guy, try to stop it.

What you see with Bruce Sutter is what you can't hit.

With tonight's game tied at 4-all in the seventh inning, Sutter came to work. The Brewers had a runner on second, two out. Sutter retired Ben Oglivie on a weak infield hopper. He went through the Brewers quickly in the last two innings.

The Brewers managed two singles off Sutter. This doesn't happen often. "Was your pitch working well tonight?" someone asked.

"Got 'em out," Sutter said. "That's the bottom line."

If we are to guess at the bottom line of this Series right now, Sutter ranks as a primary reason the Cardinals seem the better team.

The Milwaukee power men are stuck in a fortnight's slump. The 3-4-5-6 hitters -- Cecil Cooper, Ted Simmons, Oglivie and Gorman Thomas -- averaged .269 with 32 home runs and 108 runs batted in this season. For the seven games of the league playoffs and World Series, those men are hitting .170 with four homers and 13 RBI.

Milwaukee pitching is in trouble, too, unless Mike Caldwell can duplicate his masterwork of Game 1. Tonight, the Brewers' millionaire ace, Don Sutton, gave up four runs in six innings after performing brilliantly under pressure against Baltimore and California.

Pete Vuckovich, the Game 3 starter Friday, is of questionable quality nowadays, and tonight's game-losing relief by Pete Ladd emphasized the importance of the missing Rollie Fingers. Ladd, a rookie, walked in the winning run in the eighth.

Fingers, the only reliever to be named MVP and win the Cy Young award in the same year, has an injured forearm the Brewers insist is well enough to allow him to pitch an inning. Only, he never even warms up when the game is on the line. The Cardinals know Fingers is only a decoy.

Meanwhile, the Cardinals tonight exploited for the first time, but not the last, the throwing weakness of Milwaukee catcher Ted Simmons. They stole three bases. They were even so bold as to send a man who has stolen only 10 bases all year; so bold as to steal on an obvious pitchout situation.

And with any game tied in the late innings, the Cardinals have Bruce Sutter ready with his untouchable split-finger fast ball.

You may ask, as befuddled hitters have, "How does he do it?"

Pay 'tention now, this gets tricky.

Even in the short space of 60 feet 6 inches, air deflects the moving baseball. Air hits the spinning seams that stand 1/32nd of an inch from the ball's cover. Spin the seams this way, the ball rises; spin them another way, it falls. Scientists speak of lift created by vacuums; they speak of air masses colliding with seams and forcing the ball the way of least resistance.

Pitchers grow up learning the curve delivered with a snap of the wrist. A powerful fast ball will rise slightly. A slider is a fast ball delivered with half the twist of wrist needed for a curve. It breaks quickly and not as much as the slower curve.

Sutter's split-finger fast ball sinks dramatically.

"It's like an airplane coming in for a landing," said Hub Kittle, the Cardinals' pitching coach. "When it gets near home plate, it settles down to the ground."

It is Sutter's alone. "Ain't no other man ever going to throw Sutter's pitch," Kittle said. "He has abnormally long fingers; he has a real, real loose wrist, and he has the perfect conformation of arm and body to throw the way it must be done."

Sutter spreads the first two fingers to the sides of the ball. The pitch normally breaks straight down, but he says he can make it break left or right depending on pressures he applies with each finger. As he throws with a routine fast ball motion, he somehow uses his thumb, coming between the spread fingers, to apply a last twist to the ball.

"It doesn't spin like a curve," Sutter said. A curve spins globe-like, sometimes more tilted than others. "My pitch spirals like a football . . . It's a freak thing that I can do that nobody else can do."

A small favor that all hitters give thanks for.