When depth is the subject in college football, most think of only the recruiting superpowers. The conventional wisdom is that teams with the most five-star recruits have more depth and game-ready players than teams that don't regularly rank in the top 10 in recruiting.
The struggles this fall of Florida, Texas and USC obviously run counter to that conventional wisdom. And so does Oregon's success.
While the Ducks have signed only two top-25 recruiting classes since 2006 -- No. 22 last February and No. 23 in 2007 -- according to ESPN Recruiting, few teams play as many players. Coach Chip Kelly estimated that 25 players see regular action on defense, while the number is between 18 and 20 on offense.
A lot of that is due to the Ducks' pace of play: Their no-huddle offense moves quickly -- a play every 12 to 15 seconds -- meaning players need breathers. The numbers are even more dramatic on defense because the Ducks' quick-strike offensive philosophy doesn't value time of possession, see a 114th national ranking in that stat. Oregon's defense therefore sees a lot of opponents' possessions, which often leads to ignorant assessments of the Ducks only ranking 30th in the nation in total defense (they are 13th in the nation in yards per play).
Thus the constant rotation. It's typically, according to linebacker Casey Matthews, "four hard plays" then a breather.
"It's a ton of people," Matthews said. "We have tremendous backups and tremendous depth. That's the good part about this defense: When people get tired, we feel confident that the backups are prepared to fill in."
Oregon's defense features 24 players with at least 10 tackles. For comparison's sake, USC, which plays host to the No. 2 Ducks on Saturday, has only 15 players with 10 or more tackles. Arizona, owner of the No. 1 defense in the Pac-10, has 16 guys with 10 or more tackles. The numbers for some other top teams: TCU (15), Auburn (19), Boise State (20) and Michigan State (20).
And the Ducks' backups aren't just warm bodies. When Trojans coach Lane Kiffin first left USC in 2006, the Ducks' depth wasn't anything like it is today.
"I don't think until this week I realized how deep they were," Kiffin said. "For them to play so many players on offense and defense, they've got great depth."
Part of the heavy rotation is philosophy: Kelly wants to play a lot of guys. But it's also about skillful recruiting, which emphasizes speed above all else at every position, not just the skill ones. Further, the Ducks' high-velocity practices seem to help -- force? -- young players to develop quickly.
"We're not playing a kid just to say we played him -- it's not manufactured depth-- we have kids who deserve to play," Kelly said. "Sometimes getting backups involved is tough. How many reps are they getting in practice? But our guys get a ton of reps in practice because we practice so fast."
The combination of playing fast and rotating lots of players makes preparing for the Ducks more difficult. For one, there are more pages in the scouting report because more players -- and personnel groups -- must be accounted for.
Said Stanford coach Jim Harbaugh, "The different ways they mix and match that personnel, in terms of personnel groupings and formations, when you're trying to identify what their top runs are, or what their top passes are -- when there's more of them, it's hard to really pinpoint what their favorite ones are and how to defend them."
Further, the rapid-fire personnel changes make it harder to track matchups and make in-game adjustments. Oregon whipped USC 47-20 last year, and by the end the USC defense looked completely confused.
"They told me it was a fast-paced game and they really didn't have time to make adjustments," said Trojans cornerback Shareece Wright, who didn't play in last year's game because he was academically ineligible.
Another benefit from a lot of players seeing quality action? The future. While the Ducks list 11 senior starters, most of them get regular rest on the sidelines during games while younger players see action. That sort of kills the idea of the absolute primacy of "returning starters" when judging the Ducks year-to-year in the preseason going forward under Kelly, who implemented this system when he was promoted from offensive coordinator to head coach before the 2009 season.
Kelly's system, in fact, seems to nurture itself, helping in the short term -- fresh players in the game -- and the long term -- lots of experienced players on hand to off-set injuries and attrition.
So when asked if it was a matter of a "chicken or the egg" as to whether his heavy rotation was due to philosophy or a surfeit of quality players, he replied, "It's the chicken and the egg."