SCOTTSDALE, Ariz — Something’s got to give when Ohio State and Clemson face off in the Fiesta Bowl as a berth in the national championship game is on the line.

The No. 2 Buckeyes lead the nation in scoring at 48.7 points per game while yielding the third-lowest total to opponents at 12.5 ppg. Meanwhile, the No. 3 Tigers lead the nation in giving up only 10.6 ppg while being the fourth best in scoring at 46.5 ppg.

“The margin of error is very small,” Clemson coach Dabo Swinney said. “You’ve got two undefeated conference champions battling it out.”

The defending national champion, Clemson is going for its third title in four years — a run that started at the 2016 Fiesta Bowl when the Tigers shut out Ohio State 31-0.

“What matters is how we play. We’ve had one heck of a year,” Ohio State coach Ryan Day said. “Some of the things that have happened in the past have nothing to do with this team and this coaching staff.

“Everything is at stake. It’s a one-game season, a March madness mentality,” Day said. “That’s all you can focus on right now is being in the moment.”

Today’s national semifinal games are the sixth set of games since college football adopted the current playoff scenario. Ohio State is making its third appearance in the playoffs and Clemson its fourth.

“I think the committee has gotten this right since they’ve started this. They’ve gotten four great teams and I think the best team has won every single year,” Swinney said. “There are a lot of things that get voted on out there, but you’ve got to go earn this. It all comes down to those four quarters.”

The game kicks off a little after 8 p.m. tonight on ESPN with the winner advancing to take on the Peach Bowl champion (either No. LSU or No. 4 Oklahoma) on Jan. 13 in New Orleans.