Judging by the media pregame coverage of the national championship, the best way to describe the Oregon defense is "underrated" and "fast", but you also get the sense that the commentators have to say something about the Ducks' defense since so much attention has been on the offenses. Even according to the advanced metrics below, Ohio State and Oregon have the second- and third-ranked offenses in the country.
However, both defenses are ranked in the top ten in Defensive F/+ as well. There's a great reason why the Ducks and Buckeyes are in the first-ever Playoff national championship -- because both teams have earned it. And the advanced statistics reflect that.
But there's something weird about the Oregon defense too: even though overall the Ducks are ranked ninth in the country in Defensive F/+ (and 7th in Defensive S&P+ and 13th in Defensive FEI, the two metrics that make up Defensive F/+), in all of the other metrics below, they only have one other metric where the defense is ranked even in the top-30. Otherwise, the Ducks are ranked 48th against the run, 81st in Success Rate, and 95th in preventing first downs.
Below we'll try to sort this out -- what exactly do the advanced stats say about the Oregon defense and how can the Buckeyes offense attack their weaknesses?
Ohio State on Offense
|Field Position Advantage||4||7|
|Special Teams F/+||23||10|
|When Ohio State has the ball||Offense||Defense|
|Adj Line Yards||2||69|
|Adj Sack Rate||78||71|
|First Down Rate||11||95|
In the chart above, the first six rows are the overall stats or composite rankings not specific to the defense. They just give you an overall picture of the both teams.
The Oregon defense is clearly a mixed bag: ninth in the country, but not even top-30 in either Rushing or Passing S&P+. The defensive line averages a 70th-ranking in Adjusted Line Yards and Adjusted Sack Rate, which captures the line's ability to stop the run and rush the passer, respectively. So what's going on?
For one, the Oregon defense is one of the best in the country in forcing turnovers. At tenth overall in turnovers gained (with 30, two less than the Buckeyes), the Ducks have recovered an astounding 18 fumbles this season (3rd-best). Of their 12 interceptions, seven come from senior defensive back Erick Dargan. It's difficult to say what percentage exactly of those fumbles is just lucky, but considering that the Ducks are just 35th in overall Havoc Rate, it's likely that the Ducks have been somewhat lucky in which way the ball has bounced this season. Regardless, a fantastic turnover margin (Oregon leads the country in overall turnover margin at +20) will do wonders for your overall defensive ranking (just ask the Buckeyes secondary).
Other than that, the Ducks other top defensive statistic is their IsoPPP, which again is a measure for explosive plays. However, they have also allowed 224 plays of opponent 10+ yard gains (125th in the country!), so it's really hard to get a read on their ability to limit explosive plays. Part of the Ducks' solid IsoPPP score must be due to opponents' efficiency, but not explosiveness. Just looking at their Defensive Success Rate (the ability of a defense to limit efficient plays and prevent opponent first downs/touchdowns), which is ranked 81st, and their First Down Rate, which is 95th, suggests that opposing offenses have been efficient both per-play and per-drive. In fact, the Ducks allow opponents to pick up at least one first down on just over 71% of drives.
This is all good news for a Buckeye offense that thrives on efficiency. At third in success rate, eleventh in First Down Rate (picking up a first down on 76% of drives), and third in Value Drives (the ability of an offense to reach the opponents' 30 yard line on a drive), the Buckeye offense is one of the most consistently efficient in the country. The offensive line is obviously the key strength here, though Ezekiel Elliott's play also has a lot to do with it. The Buckeyes offensive line is second overall in the country in Adjusted Line Yards while Elliott is third in the country in Opportunity Rate (at 49.7% of his carries are successful in terms of working towards a first down or touchdown). Whether the Buckeyes offensive line can continue its season-long trend of paving the way for Elliott is one of the critical things to watch in the Championship. The differential between the Adjusted Line Yards rankings is one of the biggest statistical advantages for the Buckeye offense.
During the game, watch for the average yards to go on third down (ideally this number is three or less, but realistically around four is a good showing) and the Buckeyes' third down conversion rate. Against Alabama, the Buckeyes were 10/18, despite multiple third-and-longs were Cardale Jones was miraculously good. I wouldn't expect that kind of third down success two games in a row, so hope for a lower average yards to go on third down against Oregon. It also helps that Oregon has really been gashed by the solid rushing offenses that they've faced this season: before the Buckeyes, the previous-best Rushing S&P+ offense the Ducks have faced was the UCLA Bruins, who totaled 328 rushing yards and 187 alone from Paul Perkins. If Elliott has that kind of day against the Ducks, expect a win.
What will be interesting is whether Cardale will have the same kind of success on explosive play action passes to Devin Smith as he did against Alabama. Losing probable first-round pick Ifo Ekpre-Olomu to injury during bowl practices hurts Oregon here, but Oregon wasn't great at defending long passes before. For instance, Oregon is 47th in opponent passing plays of 30+ yards, and 50th in passing plays of 40+ yards. Ohio State always seeks to balance the running game's efficiency and a variety of high-percentage short passes with low-percentage, explosive play action passes to guys like Devin Smith.
Doing that stretches opponents vertically in addition to horizontally, and each makes the other part of the offense more effective. Ohio State needs to hit just a few of these play action passes to not only relieve pressure on the run game from a crowded box, but also to quickly generate points from these explosive plays (the opposite is also true; the Buckeyes need a consistent run game to have any shot at play action). Since the deep passing game is primarily meant as a constraint in the Buckeye offense, the offensive line's play really is the determining factor for the rest of the offense: if the line run-blocks well and the run game is efficient, then the Jones can have a better chance of success at the deep passing game. It should at least help that the Oregon defensive line isn't much for pressuring opposing quarterbacks, ranking 71st in Adjusted Sack Rate.
In short, the strength of the Oregon defense is in generating turnovers. If the Buckeyes are on the losing end of the turnover margin, that's very, very bad news. But if the Buckeyes practice good ball security, then the Ohio State offense should be able to turn in an efficient performance against the Ducks defense.