Lucas Nix is used to being the biggest kid in class.

"Ever since Day 1 in elementary school," said the 6-foot-6, 295-pound two-way lineman, the biggest obstacle Garnet Valley will face tonight when it plays Thomas Jefferson in the PIAA Class AAA state championship football game at HersheyPark Stadium.

Nix, a starter on defense since he was a freshman, is a big reason why Thomas Jefferson is 15-0 and seeking its second PIAA title in the last four years. Jefferson, located about 10 miles south of Pittsburgh, beat Manheim Central in the 2004 state final and lost to Gen. McClane in the 2006 semifinals.

Jefferson has posted a 55-4 record during Nix's four-year career. He already has committed to play college football at Pittsburgh, pairing with his older brother, Nate, a Panthers linebacker.

"He's a big boy, that's for sure. Very good, very athletic," said Garnet Valley coach Mike Ricci, who believes his team is prepared to face Nix and Co.

Ricci compared Nix to Steve Caputo, Unionville's 6-4, 295-pound lineman, who is headed to Temple. Garnet Valley (13-1) lined up against Caputo and the Indians twice this season, losing the regular-season game but rebounding to win in the playoffs.

"The kid from Unionville . . . very big and very athletic, so we have some experience," Ricci said.

Nix, who says technique is the key to his success, will be ready for whatever Garnet Valley throws at him, offensively or defensively. He's used to being double- and triple-teamed on defense.

"I just try to hold my ground as best I can," said Nix, who bench-presses 300 pounds. "I know that when I'm double-teamed, somebody else is unblocked and can make the play.

"I like playing both ways, although I didn't start on offense until last year. I like hitting and making bodies fly."

Garnet Valley doesn't have a special game plan for Nix, Ricci said. The Jaguars' option offense already calls for double-teams on certain plays.

Offensively, Garnet Valley will rely on guard Jon Deardorff (6-3, 250) and tackle Tim Putman (6-0, 235) to contain Nix. The other side of the Garnet line is made up of Alex Diggory (6-0, 220) and Alex Portale (6-2, 215), center Mike Fecile (5-10, 205) and tight end John Travia (6-0, 190).

Coach Bill Cherpak said Garnet Valley plays a similar style to several teams Thomas Jefferson has faced this year in the Big Seven Conference of the Western Pennsylvania Interscholastic Athletic League.

"Garnet Valley's well coached," Cherpak said. They don't rely on one kid, so they keep you off-balance."

Cherpak described Nix as a steadying influence, especially considering the adversity Jefferson has endured. In the first game of the season, tailback Brian Baldridge, a 1,600-yard rusher in 2006, went down with a knee injury. He was replaced by Orlando Torres. Cherpak also dismissed his starting quarterback for disciplinary reasons. Senior wideout Zach DeCicco moved into the QB spot.

Contact staff writer Don Beideman at 610-701-7613

or dbeideman@phillynews.com.