For a week, Tulane coach Curtis Johnson’s message to his team could be defined in one word.

Mistakes.

Repeatedly, Johnson mentioned the discrepancy between Duke’s discipline and Tulane’s lack thereof in the first three weeks of the season. And it proved to be a large portion of the gap separating the teams Saturday, when the Blue Devils rolled to a 47-13 victory over the Green Wave.

Tulane entered the game as the second-most penalized team in the country and threw more interceptions than any team in the American Athletic Conference. Neither of those numbers improved by day’s end.

“We are just killing ourselves every time,” Johnson said. “We just have to grow up and take responsibility for it. As a coach, I take responsibility for it. It’s just too many penalties and too many turnovers.”

And special teams, which was already a glaring concern, plummeted to new depths at Wallace Wade Stadium. Tulane botched two snaps on punts, costing the Green Wave nine points.

In the second quarter, Tulane snapped quickly, believing a Duke lineman was offsides. No flag was thrown, and the snap flew over the head of punter Peter Picerelli and cleared the back of the end zone for a safety.

A fourth-quarter punting meltdown was even worse. Another bad snap forced Picerelli to knock the ball to the ground, where Tulane linebacker Rae-Juan Marbley recovered before throwing a pass into the arms of Duke’s Bryon Lee, who took it 16 yards for a touchdown.

“Our deep snapper (Mike Lizanich) went out before the game, so he was done,” Johnson said. “We snapped one over our head, so I really didn’t have much confidence because (Matt) Marfisi hadn’t practiced long-snapping all week. Our snapper was hurt in pregame.”

The blunders didn’t end on the snaps, though. Punt returner Teddy Veal muffed a punt return after calling for a fair catch. Kicker Andrew DiRocco missed an extra point.

Meanwhile, Tulane repeatedly bludgeoned its own drives and aided Duke’s offense by committing 13 penalties for 92 yards and at least three others were declined.

Game of inches

Trailing 26-13 late in the third quarter deep in Duke territory, Tulane opted to go for a fourth-down conversion and came up just inches short.

Lee evaded a blitz and threw a pass to Xavier Rush, who was being corralled by Fields at the first down line. Rush bobbled the pass before pulling it in, and as he was controlling the catch, Fields drove Rush a yard behind the marker, and although Rush reached the ball out, it wasn’t far enough.

The chains measured it less than 6 inches away from a first down and although Tulane challenged the spot, the call was upheld.

By the time Tulane’s offense got the ball back, it was 33-13 and the game was essentially out of reach.

Smoking start for Duke

Tulane was caught flat-footed from the start.

Using two distinctly different methods, Duke misdirected Tulane’s defense onto its heels in the first two drives of the game, scoring a pair of first-quarter touchdowns.

After receiving the opening kickoff, the Blue Devils utilized the zone read perfectly on the opening drive to running for 75 yards in six plays (around one incomplete pass) to grab the lead less than three minutes into the game.

When Tulane responded with a touchdown drive itself, Duke took the opposite approach with equal success. The Blue Devils attacked the Green Wave defense on the perimeter, completing five passes for 75 yards to set up Josh Snead’s two-yard touchdown run.

Although Tulane eventually calmed down and only allowed one more long touchdown drive, the early damage put the Green Wave on its heels.

Lagniappe

Following Sam Scofield’s interception and fumble recovery on Saturday Tulane has forced multiple turnovers in all four games this season, raising its season total to 10. The Green Wave has forced at least two turnovers in each of its last 13 games. ... Nico Marley finished with a career-high 12 tackles against Duke, his third career game with at least 10 tackles. He had 11 against Georgia Tech two weeks ago. ... Duke was the Green Wave’s second ACC opponent in three weeks, following a 38-21 loss to Georgia Tech in the Sept. 6 inaugural game at Yulman Stadium. The Green Wave’s last road win over an ACC team was a 31-14 result at Georgia Tech in 1980.