When All-Ivy center Jake Koury ’11 graduated last year, he left no one behind him on the depth chart.

Head coach Tom Williams had to turn to his defense to find a replacement, and soon defensive lineman John Oppenheimer ’14 had been asked to switch sides of the ball. After studying the playbook through the winter and leading the offensive line through spring practice, the sophomore will be charged this year with leading the protection for Yale’s offense — considered one of the Ivy League’s deepest and most talented.

“[Oppenheimer] has worked his tail off last year and this year trying to learn the offense and a new position,” starting guard Gabriel Fernandez ’12 said. “Being a center is hard. You have to make the right calls every play and sometimes those calls need to be made in a split second for the play to be successful. He’s been doing great though.”

Oppenheimer is not a complete stranger to his new position, as he played center as well as defensive lineman in high school. But the Elis’ system is much more complicated than his high school’s, he said. And he has had to learn it in record time.

The 6-foot, 265-pounder has had help from a core of veteran teammates in making his transition, none more important than his fellow linemen. Guards Gabriel Fernandez ’12 and Colin Kruger ’12 were both regular starters last year, as was left tackle Wes Gavin ’14. Right tackle Roy Collins ’13, who moved from tight end to the offensive line last season, started two games for the Blue in his new position.

“These guys aren’t just newcomers, and that gives us some tremendous confidence up front,” Williams said.

Those veterans blocked the way for one of the Ivy League’s best offenses last season, and contribute a combined 1,082 pounds toward stopping the opposing blitz as well as a season’s worth of lessons.

“The first thing we have to do coming into this year is to eliminate the mental mistakes,” Gavin said. “The other thing we have to do is to be more dominating and physical in the run game. Our objective is to impose our will on defensive fronts. We were good in the run game last year, but we weren’t dominant.”

Oppenheimer has been holding his own among those returning starters, Williams said, and the unit has impressed throughout the preseason. With veteran quarterback Patrick Witt ’12 behind center and a stable of returning wide receivers to complement him, this year’s Yale offense has plenty of big-play potential. Throughout training camp, the offensive line’s blocking has given the offense enough time to execute those plays downfield, Williams added.

That success begins with chemistry, Gavin said, as well as the unit’s newfound intensity.

Oppenheimer has fit into the group with his extensive preparations over the offseason, Williams said, adding that the sophomore was already physically ready for the position and just had to learn how to play it over spring practice.

“What separates the average centers from the great centers is the ability to win one-on-one battles in the trenches,” Gavin said in an email. “[Oppenheimer] is using his speed to his advantage and should be a real impact player up front.”

Gavin could be the role model Oppenheimer wants to follow this season. The 6-foot-6-inch, 280-pounder became a surprise starter at right guard as a freshman last year and held his spot all season.

And Gavin’s ability on the field will only continue to grow, Williams said.

“If he fulfills the potential he has, he’s no doubt going to be a Sunday football player,” Williams said, referencing the NFL. “But obviously he has a long way to go.”

To follow in Gavin’s footsteps and transform himself from a rookie into a stalwart of the offense, Oppenheimer will have to learn to be, effectively, a secondary quarterback on the field. A center must not just block and snap the ball, but also help call the game. Every time the quarterback audibles at the line of the scrimmage, the center must convey the change to the other linemen. He must also independently recognize the defensive line’s schemes and help his teammates adjust to them.

Oppenheimer will have two tools at his disposal in learning those skills: Witt’s presence and a year spent on the defensive line.

Witt’s experience on the field and thorough knowledge of the playbook has made the transition easier for Oppenheimer, the center said.

Moreover, his experience on the defensive line last season has given him a sense of how defenses work and think, Oppenheimer added.

The Elis will get an approximation of game conditions when they take on Dean Junior College in a scrimmage Sept. 10, and Oppenheimer especially will be tested. The Bulldogs have never played Dean, and so Oppenheimer will likely face unfamiliar defensive schemes and have to react on the fly.

“For me, my biggest challenge is going to be having that same confidence against these teams when I’ve been seeing our defense every day,” Oppenheimer said. “When they’re running different schemes, I have to make same calls so we block as a unit.”

Yale allowed 18 sacks last year, tied for the third most in the Ivy League.