It's also no secret that said background contains a lot of running.
Kelly went against the grain with his zone-read-heavy spread offense at Oregon, and while he'll certainly have to make alterations to his system at the NFL level, the reality is that it would also be silly for the guy to throw out all of his bread and butter.
While I knew Kelly's Ducks offense ran a lot, I had no idea how lopsided the ratio was until Rotoworld's Evan Silva provided this recent nugget:
One of the more compelling Eagles stats I found was 685:373. That was Kelly's astonishingly lopsided run-to-pass ratio with the 2012 Oregon Ducks. While his NFL offense is unlikely to be identical, it's more confirmation Kelly is a believer in the run game as his foundation.
Even in college football, where lots of teams favor the run, that's a lot of ground work. In fact, Football Study Hall noted that only five teams in the nation ran more often on passing downs than Oregon did.
Of course, Kelly won't attempt to have the Eagles run on 65 percent of their offensive plays like Oregon did, but it's probably safe to predict that they'll run it more than they'll throw it in 2013.
And if that's the case, they'll be in the minority.
According to TeamRankings.com, only three NFL offenses ran the ball more than they threw it in 2012, but all three of those teams were remarkably successful. The Seattle Seahawks, Washington Redskins and San Francisco 49ers all made the playoffs while ranking in the top 11 in the league in scoring despite their run-first approaches.
Of course, all three of those teams ran the read-option, which is something we'll likely see from Kelly. Expect the Eagles to become the fourth team in that group, but that doesn't mean they'll suddenly become heavy hitters like the rest of them.
They're still fighting against momentum.
Between 2003 and 2009, an average of 5.1 teams per year ran more than they threw. In the three years since then, only seven total teams have possessed pass-run ratios below 50 percent.
In September, Brian Burke from Advanced NFL Stats explored current trends regarding passing, running and ratios and concluded that, if anything, the league-wide ratio should actually lean even more toward the pass than it already does.
Offenses should be passing much more often than they do. The league's run pass balance should probably be closer to 15% run 85% pass than the 40/60 split it's been in recent years. It's impossible to know the optimum league-wide ratio until teams start pushing toward the true equilibrium, but basic game theory makes it clear we're far away from the optimum. Of course, game situations dictate a bias toward run or pass in specific games, but overall, the baseline rate should be much more pass heavy.
With LeSean McCoy, Bryce Brown and possibly Michael Vick, the Eagles will have the personnel to become a run-first team—especially if that offensive line can hold up.
If that happens, it'll probably feel strange for Eagles fans used to the opposite with Andy Reid running the show. But just because something's new doesn't mean it's better and Kelly's potentially rogue offensive strategy is certainly a risky one.