By mid-October last season, Georgia Tech Yellow Jackets was 5-0 but its defense had been a sieve. Ted Roof was a realist about the situation, but his players weren't quite so attuned to the slim margin of error they'd left themselves.

"Winning can be a hallucinogen for inexperienced players," Roof said. "It masks the imperfections of performance."

Indeed, the Yellow Jackets dropped their next two games, and that dose of reality proved to be a wake-up call, Roof said. The coaching staff called a more aggressive game, the inexperienced roster gained some footing, and Georgia Tech emerged as one of the best big-play defenses in the nation in the latter half of the season, finishing with six wins in seven games, including the Orange Bowl.

But again, Roof is a realist. The Jackets were buoyed by a lot of factors that are hard to repeat, and the overall numbers still looked grim. They finished the season having allowed an average of 6.32 yards per play -- the second-most by any team in the last decade to win at least 10 games.

In other words, the job isn't done.

"There's a tremendous sense of urgency to improve in every area," Roof said.

Georgia Tech's formula for overcoming a porous defense is unique. It's offensive game plan dominated time of possession, leaving the D under-exposed. While the defense allowed a lot of big plays, it also made a ton of them -- recording a Power 5-best seven takeaways in the red zone and converting its 29 turnovers into 137 points on the year.

The problem, as Roof is aware, is that history suggests those stats are difficult to repeat.

Georgia Tech averaged a whopping 4.72 points following each takeaway last year, which ranked among the highest success rates in the nation. But look back at teams that had similar production in the past five years, and it appears unlikely the Jackets can do it again. Of the 20 teams to average at least 4.5 points per takeaway since 2009, only two exceeded that mark again the following year. On the whole, that group saw a 27 percent reduction in scoring following a takeaway.

Moreover, those seven takeaways in the red zone were likely something of an anomaly. In the last decade, 17 Power 5 teams had at least seven red zone takeaways, but their production in that area decreased by 65 percent, on average, the following year.

Takeaways in general are a luck-based metric, and when Georgia Tech didn't get a turnover last season, it allowed points on half its opposition's drives -- the third-worst rate among Power 5 schools.

Perhaps the best point of comparison is the last Yellow Jackets team to win 11 games. In 2009, Georgia Tech went 11-3 while allowing 6.1 yards per play, the fifth-worst rate among BCS-conference teams. A year later, the defense made small improvements (5.7 yards per play) but saw its turnover rate dip by 13 percent and its offensive performance decline. The result was a 6-7 season.

Of course, there are problems with the comparison to that 2009 team, too. Georgia Tech's offense is led by star quarterback Justin Thomas and is less likely to take a big step back this year. In 2009, Tech feasted on a poor ACC, but last year's defense was stung by a litany of challenging offenses. And perhaps most importantly, Roof's history suggests he's prepared to take what was an inexperienced unit last year and improve far more dramatically than that 2010 team did.

In fact, the results are already evident. During those early struggles for the defense last year, it allowed its opponent to exceed its season average in yards per play in six of seven games. In its final six contests (that included games against five teams that would finish with eight or more wins), Georgia Tech's defense held its opposition below its season average four times. The growth was clear.

"What leads to most of the points that are scored is breakdowns in communication," cornerback D.J. White said. "Having guys being back there that are comfortable, they don't get ahead of themselves."

Up front, things are improving, too. KeShun Freeman made huge strides as a freshman. Jabari Hunt-Days remains on track to return in 2015. Reserve linemen like Antonio Simmons and Kenderius Whitehead are expected to be bigger contributors this year. The aggressive play calling Roof was forced to use to get to the quarterback last year can be dialed back, and he's optimistic that will translate into fewer big plays allowed.

The bottom line is that Roof's assessment of his defense is a realistic one. It has to get better if Georgia Tech wants to repeat as Coastal champs, but there's also every reason to think that will happen.

"It's our job to get better, and that's what we've worked to do," Roof said. "The proof is in the pudding, but I'm looking forward to this season as much as any in a long time."