Luis Ramirez's fastballs do not impress radar guns. Often clocked in the high 80s, the pitches seem destined for the fat part of many a bat.

"And then, Boom!" marveled Jesus Alfaro, one of Ramirez's coaches with the Class A Aberdeen IronBirds. "Then it just explodes."

Alfaro thought back to the first time he saw this fastball -- a pitch that has earned Ramirez a baseball strikeout record, national acclaim and a rapidly expanding tally of strikeout victims.

"How can this guy throw like this?" Alfaro asked in the spring of 2002, more than two years before Ramirez became the first pitcher at any American professional level to strike out 12 consecutive hitters.

Ramirez's fastball is what scouts like to call "sneaky fast" -- an apparent rising movement as it nears the strike zone makes it look 6 or 7 mph faster than radar guns indicate, teammates and opposing coaches said.

Ramirez's emergence in the Orioles' farm system has had similar late movement. He had a suitably discreet baseball beginning, signing with the Orioles as an undrafted free agent in 2000. Baseball America doesn't include the 22-year-old right-hander among the Orioles' top 10 minor league prospects, and the team's media guide swings and misses on his country of origin, listing Curacao instead of Venezuela.

Peggy Rhodes, an IronBirds employee who houses Ramirez and two teammates in her Harford County home, said he's so quiet "you wouldn't even know he's around." Orioles minor league pitching coordinator Dave Schmidt wades into the same adjective pool: "easygoing, quiet, doesn't get excited."

But with that one pitch -- a seemingly modest fastball that suddenly leaps and struts as it reaches the batter's box -- Ramirez has thrust himself into the spotlight, tearing through his short-season Class A opponents during an extraordinary four-week span.

On June 23, his second start of the season, he fanned 12 consecutive Jamestown hitters, a record in major or minor league baseball. Ramirez left after five innings because of pitch count restrictions, departing with 15 strikeouts and instant celebrity.

"He was just in control the whole time, and the ball exploded out of his hand," said Jamestown Manager Benny Castillo. "He's going to be in the big leagues in a couple years -- that's about it."

Suddenly, Ramirez was the prime target of autograph seekers, including an Aberdeen usher who admitted he wasn't supposed to do such things but made an exception this once. Ramirez switched uniform numbers so that Aberdeen team officials could send his hat and game jersey to the Baseball Hall of Fame. His performance was recounted in Sports Illustrated and dozens of national newspapers, and the Orioles named him their minor league pitcher of the month, an honor not normally bestowed upon short-season players.

"We kind of bent our own rules a little bit," said Orioles director of minor league operations Doc Rodgers. "Clearly, he went above and beyond the call of duty."

At Ramirez's next home start, July 3 against New Jersey, he was perfect through five innings. He threw six innings and struck out 11, including seven in a row. One man out of 19 reached base -- on an error.

"He was doing it all," Aberdeen catcher Morgan Clendenin said. "I didn't have to do nothing but put my glove up and put down a sign."

Last Wednesday, Ramirez was home again, and the swinging and missing continued in his sixth start of the year. He allowed a leadoff single, promptly picked off that runner off and then retired 12 straight batters. At one point, he struck out five in a row, all flailing at fastballs.

"This guy right here looks like he throws golf balls out there," said teammate Chris Smith, sitting behind home plate and staring at radar readings that rarely rose above 89 mph. "You think it should be out of the park, and Boom!, it's just by the guy. Just by the guy like it was 100 mph. . . . He's just got that extra whatever-it-is."

While others try to explain this late bounce -- Clendenin calls it "the gift," and Aberdeen pitching coach Andre Rabouin says "it's just something he's blessed with" -- Ramirez claims his success isn't very complicated.

"As I move up, I know that I have to work on other pitches, but it starts with the fastball," he said through Angel Natal, an employee with the Cal Ripken Sr. Foundation who suddenly finds himself functioning as Ramirez's Spanish interpreter (Ramirez speaks only minimal English). "My approach is simple. I try to get a first-pitch ground ball. Then, with two strikes -- go for the strikeout."

Ramirez has added 10 or 15 pounds to his still lanky 6-foot-4 frame over the past three years, and teammates speculate that his height might add to the fastball's verve. The pitcher's father, Luis, a government contractor, is 6-7. Two younger sisters each flirt with the 6-foot mark. In fact, Ramirez fancied himself a basketball player until he was 16, when a scout spotted him throwing a ball in a casual game with friends.

After signing with the Orioles, he pitched in the Venezuelan league, and by 2002 he was a reliever with Baltimore's rookie league team in Sarasota. He led the Gulf Coast League with 15.7 strikeouts per nine innings, but a high earned run average and occasionally spotty fundamentals brought him back for another year in Sarasota, where he became a starter and again led the league in strikeouts per nine innings.

Despite his first rough outing of the season last night, Ramirez easily leads the New York-Penn League with 57 strikeouts in 36 innings -- an average of 14.25 per nine innings -- and has yielded only 21 hits and nine walks.

But one pitch, however potent, will likely not be enough to propel Ramirez through the Orioles system. Rodgers noted that John Maine struck out hitters at a similar rate last year in Delmarva -- 12.7 per nine innings -- but remained in less advanced Class A all year to polish his repertoire. Several Orioles officials said that Ramirez needs to work on his breaking ball and change-up while also locating his fastball lower in the strike zone.

In the meantime, Ramirez said he's satisfied pitching for Aberdeen, sleeping in a bunk bed with fellow Venezuelan Arturo Rivas and borrowing Rhodes's TrailBlazer for trips to Wal-Mart and the mall.

"Obviously I'd like to move up, but it's not up to me," he said. "I'm just here doing my job. Once the Orioles ask me to move up, I'd be happy to."

His teammates have less measured assessments -- "Mariano Rivera Number Two," said shortstop Elvis Morel. And Aberdeen's coaches acknowledge that Ramirez's results have not exactly been ordinary.

"He can go a long way. He can go and be an all-star pitcher if he keeps going like that," said Alfaro, who also managed Ramirez in Sarasota. "With the stuff he has, you cannot find that, you cannot teach that."

Aberdeen right-hander Luis Ramirez doesn't throw exceptionally fast, but he lit up the baseball world with 12 consecutive strikeouts on June 23. Aberdeen pitcher Luis Ramirez chats with catcher Brian Bock during a recent outing. He "looks like he throws golf balls out there," says Chris Smith, another teammate. "He's just got that extra whatever-it-is."