Someday a little boy is going to look in the Baseball Encyclopedia and see that two men, born four months apart, played in the major leagues together for 20 years and had career records almost as identically even as could be imagined.

That little boy is going to think that Steve Carlton and Don Sutton probably had something in common.

Boy, is that boy gonna be wrong.

At the moment, Carlton has 318 wins and Sutton 301. But, since Carlton has been released by the Philadelphia Phillies and Sutton (6-5) still is fairly effective for the pennant-contending California Angels, that gap may diminish or be erased. Carlton has 10 fewer losses and an edge in career ERA: 3.09 to 3.20. Overall, Carlton had better hitters behind him, Sutton better relievers.

Both are 41 and have pitched an almost identical number of innings (about 4,900) and allowed almost the same number of hits (about 4,300). Carlton actually has been slightly easier to hit and has walked more than 400 more men. But Carlton has struck out about 600 more and given up home runs at a lesser pace.

Sutton has 56 shutouts, Carlton 55. Both have pitched for five division and four pennant winners. Sutton is 6-4 in postseason, Carlton 6-6. Both have been nearly indestructible. That's about how close they are.

When else in baseball history have two men been so statistically similar, yet so utterly opposite both as pitchers, public figures and people.

On the mound, the 6-foot-5, 220-pound Carlton was a classic left-handed intimidator. As Clint Hurdle once said, "When you call a pitcher 'Lefty' and everybody in both leagues knows who you mean, he must be pretty good."

Carlton threw the three basic pitches of his era and used them in predictable patterns. High fastball, vicious slider down-and-in to righty hitters, and a sweeping curveball. For left-handers, he was a nightmare -- "like drinking coffee with a fork," said Willie Stargell.

Some righty hitters -- particularly Johnny Bench, who owned him -- gave Carlton fits because he was incredibly stubborn and predictable. (After all, he did lose 223 games.) Carlton believed his pitches complemented each other, one setting up the next; some foreshadowing shouldn't really help the poor hitter much. Carlton, obsessed with dominating and controlling every situation, wanted a battle plan in which he could believe absolutely just as, in his martial arts training regimen, he wanted to feel he was a step beyond everyone else.

Where Carlton was smooth and graceful, with the best and most liquid pickoff move since Warren Spahn, Sutton seemed stiff, too erect, slightly herky-jerky and mechanical. Not pretty, barely memorable. Nothing about Sutton, from his 6-1, 190-pound build to his fastball, which rarely broke 90 mph, was too impressive.

His curveball had more variety -- of speeds and swerves -- than raw quality. Most important, he could throw it for strikes behind in the count as well as any pitcher of his time. What Sutton's fastball lacked in heat it made up in life -- his ball ran and nicked corners. Naturally, he was sneaky, too, outfoxing everybody and constantly jamming power hitters. Nobody had more gall or staying power with bad stuff. Sutton battled.

Some players think Sutton cheated. And was proud of it. Nothing tickled him more than being accused of scuffing and defacing the ball. Thanks to who knows what hidden tools, he could throw a fullspeed fastball that, a few feet from the plate, would suddenly acquire sinker or screwball properties of its own volition. When Sutton won his 300th game last week, a bitter rival player said that he'd scuffed so many balls (which had to be thrown out of play) that every CYO team in town could have a new supply.

While Sutton was perhaps the most consistent pitcher in history from one year to the next, Carlton had spectacular highs and lows. For 20 straight years, Sutton never worked less than 212 innings (except in strike-shortened 1981, when he was on a 240 pace.) Sutton also lost more than 15 games only once. By contrast, Carlton led the league in defeats twice.

As most fans know, Carlton was the only man to win four Cy Young Awards and had six 20-win seasons. This properly established him in the public mind as a giant. "Carlton's the best pitcher in the world," said Pete Rose, "unless the Russians have got one I haven't seen."

Sutton, however, only won 20 once. Because of the sacred qualities attributed to the arbitrary number "20," it took Sutton a whole career to be considered a Hall of Fame candidate. If, for some reason, baseball worshiped the number 17, then the tally would favor Carlton, 8-7. Or, if 15, then Carlton would lead, 12-11. Carlton was better, but by far less than usually supposed.

Both pitchers fed their contrasting images. Carlton was probably the most arrogant, serious and reclusive player of his time. By contrast, no star was more prone to being silly, self-deprecating, and available than the sardonic Sutton is. Carlton wanted to bully; Sutton prefers to sneak up behind.

When Sutton obliterated most of Sandy Koufax's team records with the Dodgers, he said, "Comparing me with Koufax is like comparing Earl Scheib with Michelangelo."

For years, Sutton was the Dodgers' resident dissident in the Lasorda Era.

"I'm leery of Tommy. I believe in God, not the Big Dodger in the Sky," Sutton said when Lasorda appeared.

Sutton took himself no more seriously than he took others. As he bounced from the Dodgers to the Astros to the Brewers to the A's to the Angels -- usually helping somebody in a pennant race -- he quipped, "I'm the most loyal player money can buy."

While Sutton played Columbo, Carlton created an opposite media mystique -- one of utter silence. At times it has almost seemed as if Sutton deliberately counterpointed himself to Carlton -- to his advantage. After an early knockout this year, Angels boss Gene Mauch told Sutton to go home early to change his luck. Sutton called the press box and asked, "Anyone have any questions before I leave?"

Now, Carlton and Sutton's pathes may finally diverge.

With his $1.1-million contract and 5-16 record over the last two seasons, Carlton seems done. Just as all admired his skill in his prime, so few will miss or mention him after he's gone.

Sutton somehow keeps functioning -- 14-12, 15-10 and 6-5 (so far) the last three years. Good enough to stay employed. He wants to play in '87 and beyond. Then, he matter-of-factly says, he intends to stay in the game in some visible capacity forever.

"Yes, it's just a job, and I don't get my self-worth from it," he says. "But . . . it is irreplaceable."

Only a few years ago, Don Sutton would have had a hard time making a list of the 10 greatest pitchers of his own era within his own league. Where he ranked in history would not have been thought a serious question.

At the moment, Sutton needs just 18 more victories to move into fifth place in wins among all the pitchers of the 20th century. The top four are Walter Johnson, Christy Mathewson, Grover Cleveland Alexander and Spahn.

Carlton may have been the quiet one, but it was Sutton who was sneaking up on us all along.