Her fingertips gripping the red lace of a worn baseball, Chelsea Baker looks down from the mound. She shuffles her feet, winds up and with a swift push sends the ball zigzagging through the air.

"Knuckleball," she says in her soft twang.

Chelsea, 13, of Plant City, Fla., has been called the nation's best Little League player. She pitched two perfect games in a year. She's been profiled by ESPN and approached by movie directors. She makes boys cry.

But the most recent excitement came in the form of a call from the National Baseball Hall of Fame in Cooperstown, N.Y. They want Chelsea's jersey.

"I didn't really believe it," Chelsea said, while practicing last week at a park with her stepfather, Rod Mason. "I was beside myself, just overwhelmed."

Chelsea, her stepdad and her mother, who works as a dental hygienist, already had booked plane tickets for the annual Cooperstown Dreams Park Tournament of Champions this week. Sometime during the trip, when she's not out on the field, Chelsea will hand over her jersey in person.

John Odell, the Hall of Fame's curator of history and research, said the No. 12 jersey Chelsea wore in her second perfect Little League game will hang in the Diamond Dreams exhibit, which showcases notable women in baseball.

Of the Hall of Fame's approximately 36,000 artifacts, few are from female players and even fewer are from youth players, Odell said.

"We're not saying this is the only time that it's ever happened, but we do think it's noteworthy," he said.

Chelsea figures she's played in hundreds of games since she started T-ball at 5. She practices for at least an hour and a half, four days a week.

What made her so successful is the nasty knuckleball she learned from Joe Niekro, a retired major-league pitcher who was Chelsea's former coach.

It took Chelsea two years to get it just right, starting at age 8. But now, "it's easy," she said. She wound up again and threw the ball forward. "See?"

Niekro died in 2006, at 61. At his funeral, Chelsea placed a baseball in his casket.

If her coach could see her now.

Her stepdad said he can't quite believe it sometimes.

"I can't even put it into words," Mason said.

Chelsea, who is about to start eighth grade, said she's still getting used to all the attention.

"I always just wanted to play baseball," she said.

But does she mind all the spotlight? "No ma'am."

Kids at school ask her for her autograph. She sheepishly admits that she's been practicing.

Chelsea has other hobbies, too. She likes to play piano and says she's pretty good at drawing cartoons, graffiti-type stuff, mostly.

Still, she spends most of her time peering over her little glasses toward home plate.

Does she want to do this forever? Chelsea pauses, as if she hadn't thought of it.

"Right now I'm going to try to play high school baseball," she said, lobbing another pitch to Mason.

They wrapped up the practice session and headed back to the car. A man who had been watching walked up. "Excuse me, is that the famous Chelsea Baker?"

Chelsea smiled, shrugged.

"What's your secret?" the man asked, with his 9-year-old son standing quietly by.

Mason looked over at Chelsea.

"It's right here," Mason said, patting his chest. "It starts in the heart."