Baseball scouts, a quarrelsome group who rarely agree on anything, were unanimously impressed a few years ago by a prospect named Roger Clemens. Virtually every scout who ever saw him play said there would be nights when Clemens, with his 95-mph fastball, would be unhittable.

On Tuesday night in Boston's Fenway Park, the 23-year-old Red Sox pitcher came the closest of any in the history of the sport to being literally unhittable. He struck out 20 Seattle Mariners, a major league record for a nine-inning game, in Boston's 3-1 victory. Seattle hit only 10 balls into fair ground. Only three were hit safely, and only two were pulled.

The Red Sox don't have a radar gun at home games. But a Toronto Blue Jays scout clocked Clemens' fastball at 95 mph consistently, and as high as 97. He didn't walk a man, and didn't even run up a three-ball count after the fourth inning.

"People who were here saw history that won't be broken," Seattle's Gorman Thomas told The Boston Globe. Thomas hit a home run to center field in the seventh, but said, "When the last out was made Phil Bradley's fourth strikeout , I wanted to tip my hat. He was that good. It was the finest effort you'll ever see."

Red Sox management was obviously happy but also quite surprised to see Clemens' early success this season. On Aug. 30 of last year, Clemens had shoulder surgery for a muscle tear. He was knocked around a lot in spring training and team officials didn't know whether he could make a substantial contribution until midseason.

Even now, some of the Red Sox people have been apprehensive about Clemens' shoulder, and are waiting until he pitches 100 innings (Clemens, with a 4-0 record, has pitched 33 innings this season) before getting their hopes way up.

Until then, at least, Clemens has his incredible record to ponder and enjoy.

"This will be something I'll cherish for a long while, and I hope it stands for a while," Clemens said. " . . . It's been a long road back. It feels good to go out and win like that. I was challenging guys."

Going after hitters with fastballs is what the Red Sox expect Clemens to do. As a rookie in 1984, he struck out 15 Kansas City Royals hitters in one game. A week ago Tuesday, in his previous start, Clemens struck out 10 Detroit Tigers in 6 2/3 innings. He does have a hard slider and a curve. But at 6 feet 3, 210 pounds, Clemens is the classic power pitcher. After leading the University of Texas to the College World Series three years ago, he was compared to Tom Seaver.

The record of 19 strikeouts was held by Nolan Ryan, Steve Carlton and Seaver; the last two were Clemens' boyhood heroes. "Those are the two pitchers I always wanted to be like," he said. "I tried to combine the makeup of both."

Neither Seaver nor Carlton can throw a 97-mph fastball anymore. With that kind of smoke, Clemens had one basic approach the entire game. "He said, 'Here's my fastball, hit it.' He didn't mess around," said Mariners second baseman Danny Tartabull.

Red Sox catcher Rich Gedman said Clemens threw fastballs more than 80 percent of the time "and they were unhittable." Third baseman Wade Boggs said all he did was "play catch" with Gedman after the strikeouts.

Clemens, who also tied a major league record by recording eight consecutive strikeouts (between the fourth and sixth innings), had struck out 18 after eight innings. Of the 138 pitches he threw, 97 were strikes.

Before the ninth inning, Al Nipper, another starting pitcher for the Red Sox, told Clemens he had a shot at the record. "He told me I was within two strikeouts and to go out and get it," Clemens said. "And I did."

The Mariners are no strangers to strikeouts this season. Through Tuesday night, Seattle hitters had struck out 186 times in 20 games, an average of 9.3 times per game. Projected over the 162-game season, the Seattle total would surpass the strikeout record, set by the 1968 New York Mets, by 25 percent. Oakland's Jose Rijo struck out 30 Mariners in two starts this season. Outfielder Bradley has struck out 20 times in his last 44 at-bats.

Even so, Clemens' performance is likely to stand for some time, and it was a fulfillment of sorts for someone who had been compared favorably with peers Dwight Gooden of the Mets and Bret Saberhagen of the Royals -- the Cy Young Award winners in 1985.

The strikeouts, and the comparisons, will continue, no doubt. Clemens has been throwing that well this season.