Softball batters facing Williamstown ace Rachael Matreale can expect blazing fastballs and devastating drops from the 5-foot-11 athlete.

They also can expect the unexpected.

The best thing in Matreale's pitching repertoire is the element of surprise. Her change-up baffles hitters and leaves her coach and teammates shaking their heads in disbelief.

"She could tell the kid it was coming and it still wouldn't matter," Williamstown coach Fred Powell said. "It's like watching a cartoon. The hitter could swing at it twice and they still wouldn't hit it."

Said Williamstown junior second baseman Katie Trotter: "Rachael's change-up, it's just amazing."

Matreale's pitching has Williamstown in the hunt for the program's first state title. The Braves are 23-1 and play top-seeded Toms River East today in the South Jersey Group 4 championship game.

Matreale, a senior who has committed to attend Rider University on a combination athletic/academic scholarship, has an 18-1 record with an 0.16 ERA. She's thrown 16 shutouts, struck out 199, and allowed just 3 earned runs in 129 innings.

"The whole team has been pointing toward this season for a long time," Matreale said. "We all knew we had a chance to have one of the best teams ever at Williamstown and we were determined to work as hard as we could to make that happen."

Hoping to make the most of her senior season in softball, Matreale made a tough decision in the late fall: She opted not to play basketball after three years in the Williamstown program.

Instead, she spent the winter working with her longtime pitching coach, Tom Besser, and with her father, Jim.

"It was hard because I loved playing basketball," Matreale said. "But I knew I was going to play softball in college and I wanted to really work on my pitching."

Said Powell: "It really was a sacrifice for Rachael to give up basketball. But she did it because she wanted to do as well as she could this year in softball."

Matreale, who also played four years of volleyball for Williamstown, has been firing fastballs since she first stepped into the pitching circle as an 8-year-old.

Not that she knew where the ball was going.

"I used to hit people all the time in Little League," Matreale said. "Kids used to quit. I still get people who tell me they have bruises from when I hit them in Little League."

Matreale said it wasn't until she was in "eighth or ninth grade" when she developed some command on the mound, and it wasn't until the last year that she took the step from talented, promising player to polished product.

The big thing was the development of her change-up. She throws a "circle change," using the same arm motion as her fastball but relying on a different grip to result in a much slower pitch.

"The big thing is having the same arm speed," Matreale said. "I've always thrown it, but never as much as this year. I've just gotten better and better at throwing it.

"It's a great pitch against strong hitters. I'm throwing it against them a lot."

Trotter, who also serves as the team's backup pitcher, said Matreale has been a dominating presence on the mound this season.

"She's so intimidating because of her height and how she throws," Trotter said. "She's done an excellent job this year."

Matreale's pitching, plus some strong defense and timely hitting, has second-seeded Williamstown riding high entering today's sectional final.

"It's been an amazing season so far," Matreale said last week before pitching a no-hitter against Delsea. "We're all supporting each other and we have high expectations for the playoffs. We don't expect anything less than a state championship."

Contact staff writer Phil Anastasia at 856-779-3223 or panastasia@phillynews.com.