BAYONNE, N.J. — On the pitcher's mound, a 12-year-old girl from New Jersey is perfect.

Mackenzie Brown is the first girl in Bayonne Little League history to throw a perfect game. She retired all 18 boys she faced on Tuesday.

There are no official records of how many perfect games are thrown per season. Little League Baseball in Williamsport, Pa., estimates only 50 to 60 occur each year. No one knows how many have been thrown by girls.

Brown says she knew she had something special going in the fourth inning and just tried not to mess up.

She'll get to throw out the first pitch at Citi Field on Saturday when the New York Mets host the Washington Nationals.