The first reaction of many baseball fans to the news that Baltimore's Steve Stone has won his 14th consecutive game, or that Pittsburgh's Jim Bibby has a 13-1 record, is to scoff.

How can two career mediocrities suddenly have the best winning percentages of all the starters in their respective leagues?

Just a season ago, Stone and Bibby had reached points where their career records were 73-79 and 69-76. Since then, Stone has gone 21-3, Bibby 25-5.

Such total transformations in baseball old age -- Stone is 33 and Bibby 35 -- are unheard of, impossible, and must be short-lived flukes.

No, sir. No such thing.

Stone and Bibby, as well as two of baseball's other biggest winners of this season -- Tommy John (15-4) and Larry Gura (14-4) -- are very much a part of a century-old tradition: late blooming pitchers who go from bad to great. And then stay that way for years.

What fan has not heard of Preacher Roe, Allie Reynolds, Herb Pennock, Mike Cuellar, Red Ruffing, Eddie Lopat, Bucky Walters, Hippo Vaughn, Wilbur Wood and even 300-game winner Early Wynn? All, at one time, were the Stones and Bibbys of their day.

Every baseball generation, since the 1890s when Red Donahue went from a 33-game loser to a 20-game winner, has produced just such hurlers who, after being permanently tagged and docketed as bums and losers, suddenly discovered some key that opened the door to becoming part of the game's permanent lore.

Without doubt, these are rare birds -- pitching phoenixes who rise from the ashes of a decade or more as nonentities to become the premier stars of their sport. They are, however, not nearly so rare a species as might be assumed.

At this moment, four of the top five percentage pitchers in baseball -- Stone, Bibby, John and Gura -- are perfect illustrations of the type. John was 84-91 (.480) before a trade at 29 to Los Angeles; since, he's 123-55 (.691). It took Gura 10 seasons before any team would give him a regular starting job; since, in 2 1/2 years, he's 43-20 (.683).

Other recent 20-game winners have had only slightly milder turnarounds: Mike Caldwell, whose career went from 40-58 (.408) at age 29 to 47-22 (.681), and Joe Niekro, who at 32 flip-flopped from 68-75 to 68-49 therafter.

The transforming factor is never a mystery. Usually, it is one of several things: a trade to a better team, a new pitching coach, a change in psychological approach, a new pitch.

Or in Stone's case, all four at once. He is an almost perfect example of what subtle changes can do to turn an overlooked athlete into a suddenly self-confident champion.

Coming from the good hit, no field Chicago White Sox to AL champ Baltimore, Stone learned to trust his defense and to stop trying for strikeouts. From a new pitching coach, Ray Miller, Stone learned to trust his decent fast ball more, so that it would make his "out pitch" -- the curve -- seem that much better.

Stone also learned a passable, if erratic, forkball he can showcase to hitters to distract them. Finally, as is so often the case, the last piece of the puzzle concerned the head far more than the arm.

Once, Stone admits, "I expected everything to go wrong." Now, he spends an hour meditating before each game, visualizing how things will go right all four times he must face each hitter.

"I've stopped believing that whether a ball curves fair or foul, or whether a fly ball goes over the fence or not, is entirely luck," Stone says. "If you are confident, work fast, and transmit an air of certainty that you'll win, that the other team hasn't got a chance, it seems the breaks start going your way."

If Stone were a student of baseball history, he would find it much easier to ignore the whispers around him that say his record is a fluke. If the past is prologue, Stone may have a lot of pancakes ahead of him. Usually, when a pitcher in baseball middle-age makes the jump to hyperspace, he doesn't come back to earth until old age finally wears him out. In other words, once the secret is found, it stays.

If Stone, at 16-3 tied for the major league lead in wins and needing two more victories to tie the AL record for consecutive wins in a season, should have trouble sleeping, wondering if he is a baseball Cinderella waiting for midnight to toll, he should comfort himself with a century of precedent.

Herewith, we offer 10 of the most startling transformations in modern pitching history, men who have succeeded at what Stone and Bibby now are attempting. All spent a significant part of their careers as losers, or marginal winners, before suddenly shooting to the very top of the heap.

These are not the prodigies who took a few years to find their form, the Sandy Koufax who went from 36-40 to 119-47, or Hal Newhouser, who, after a 34-54 start, went 80-27 the next three years.

These are men, who, it was almost universally thought, had sought their true level: a low, or at best modest, one.

Perhaps the most Stone-like of all was Preacher Roe. When Roe came to the Brooklyn Dodgers from Pittsburgh in '48, his mark was 34-47 (.420) and his age 33. Over the next six years, he was 90-33 (.715) as a Dodger, including 22-3 in '51.

"I never knew so many balls could be caught," Roe said after seeing the Dodger defense. Also, Al Lopez taught him the slider.

Allie Reynolds, the Superchief, was a paltry 51-47 at age 32 when Cleveland traded him to the Yankees. Thereafter, he was 131-60 (.686) and won until he was 39.

Of all teams, the Yankees have, not surprisingly, proven the best tonic to pitchers who joined them. Pennock, the Knight of Kennett Square, was 59-59 as a Red Sox, but 115-57 (.669) in his first six years as a Yank after a trade in 1923 at the age of 29. Eddie Lopat, 50-49 as a White Sox, also got the gift of pinstripes at age 30 and was 109-51 (.681) for the next seven seasons.

No Yank, however, was refurbished like Ruffing. As a Red Sox, he was 39-96 (.289) with back-to-back seasons of 25 and 22 losses when the Yankees grabbed him in 1930. For the next 15 years, Ruffing was 231-124 (.651) and made Cooperstown.

If Lopat learned to change speeds, then Wilbur Wood, who was 37-46 at age 29, learned to love the knuckleball and a two-day rest rotation after Johnny Sain arrived as pitching coach. Wood won 90 wins in the next four years ('71-'74).

Sometimes, winning is nothing more than trust. "Earl Weaver stuck with Mike Cuellar every cold spring while he got bombed," said George Bamberger, then O's pitching coach. "I gave Cuellar more chances than my first wife," Weaver said. The result: hot-weather Cuellar, 37-36 at Houston, came to the Orioles at age 32 and was 125-63 in his first six Baltimore seasons.

Perhaps the most sudden of all turnabouts was Bucky Walters, who lost 21 games in 1936 for Philadelphia, and had lifetime numbers of 38-53, before going 60-27 (.690) in his first 2 1/2 years as a Red.He won 72 games in the next four years in Cincinnati.

Nonetheless, the two most similar -- and dramatic -- of all the awakenings are those of John and Early Wynn. Wynn was 72-87 (.453) after eight years with Washington, just as John was 84-91 after nine seasons with the Indians and Chisox. Both escaped to better teams at age 29. Wynn went on to win 228 with the Indians and White Sox, while John may, at this moment, be the most effective and dependable starter in baseball.

"I'm no Walter Johnson or Lefty Grove," Stone said last week, after hearing they were among those who had won 16 straight.

What Stone does not realize is that baseball has always had two categories of great pitchers. One is that larger group of naturally-blessed Johnsons and Groves, Palmers and Seavers. A smaller and less noticeable group of men also exists -- pitchers who found greatness unthinkable, until, all at once, they stumbled onto it.

For them, after years of defeat, victory may be even sweeter.