by Bill Connelly

Last time around in Varsity Numbers, we took our first stab at ranking offensive lines. The rankings revolved around two figures: Line Yards+ (a basic measure of the line's responsibility for rushing success, common to FO, and adjusted for strength of schedule) and Sack Rate+ (a stab at another FO-centric measure, Adjusted Sack Rate, once again schedule-adjusted). The fun thing about line rankings is that, in theory, you can use the same measures to evaluate both offensive and defensive lines.

So with that in mind, let's use the same measures to see what we can learn about defensive line play in both 2008 and 2009. Then, at the end, we'll take a look at some individual playmakers.

(And yes, we know that we're measuring the linebackers along with the defensive linemen with these team stats, but this article focuses specifically on the defensive line... with individual stats as well, as you will see shortly.)

Line Yards+

Who had the best defensive lines in the country in terms of stopping the run? Included in the following table are each team's Line Yards+ rating, their raw Line Yards per Carry average, and their overall Rushing S&P+. As we learned a couple of months ago when we looked at overall defensive rankings, TCU mastered the art of the "+" in 2008. Even with a strength of schedule adjustment, TCU ranked head-and-shoulders above just about everybody else in multiple categories, as you'll see below.

A few thoughts:

• TCU has to replace three of four defensive line starters in 2009, though they do return the best of the bunch, senior stud Jerry Hughes (15 sacks, 4.5 tackles for loss, and a couple of interceptions for good measure). It was a perfect storm of experience, athleticism, and a challenging schedule for the Horned Frogs in 2008 -- expect a fall back into the teens for TCU this year, which should obviously still put them at the top of the pack for non-BCS defenses.
• How important to the Mississippi defensive line was Peria Jerry? We'll find out -- Jerry's departure is the only significant loss for Houston Nutt's line. If Jerrell Powe ever starts to act like the big-time recruit he once was, the Rebels could have the best defensive line (in terms of rushing) in the country in 2009.
• You would expect a team with two huge, highly-drafted defensive tackles (B.J. Raji and Ron Brace) to sport a run-stuffing defensive line, and Boston College sure enough did. (Oddly, despite the presence ACC Defensive Player of the Year Mark Herzlich, the Eagles' linebacker corps was apparently weak enough to drop B.C. to 23rd in Rushing S&P+ despite such a sturdy line.) The 2009 Eagles line is stocked at end but predictably raw at tackle.
• As you will see below, South Florida was mediocre rushing the passer despite the presence of star end George Selvie, but they were quite stout against the run. With Selvie back to 100 percent health (he was hobbled and double-teamed most of 2008) and both starting tackles -- Terrell McClain and Aaron Harris -- returning, USF could cause nightmares for opposing running backs.
• Defensive back Eric Berry justifiably gets all the attention when people talk about the Tennessee defense, but the line was stout. UT will sport a re-tooled front four in 2009, as end Robert Ayers (a first-round draft pick) and tackle Demonte Bolden are both gone. Big tackle Dan Williams (6-foot-3, 330 pounds) will need to step up his game if UT wants to remain near the top in this category.

Sack Rate+

As with the offensive line stats, the Sack Rate+ figure is both more volatile (higher highs, lower lows) and mid-major friendly than Line Yards+. You could say that there are a lot ways to attack the quarterback, but not nearly as many to stop the run.

Of course, there is no variability regarding the top team on the list.

Teams in the top 20 in both Line Yards+ and Sack Rate+: TCU (first in LY+, first in SkRt+), Texas (10th, second), Virginia Tech (19th, fourth), Penn State (eighth, 15th), Michigan (13th, 16th), Missouri (18th, 20th).

• Nebraska has gotten a lot of mileage out of their defensive line this offseason -- it's the main reason they have been named a preseason Top 25 team and Big 12 North favorite. As you will see with the playmakers section below, the Huskers (one in particular) made a ton of big plays in 2008, but they struggled in both down-to-down consistency and run stopping. Clearly if you are a Big 12 defense, sacking the quarterback matters a hair more than stopping the run, but Nebraska will need to improve in run stoppage if they are to live up to preseason hype.
• Speaking of preseason hype, for Texas to maintain their stalwart defensive performance from 2008, a series of previously highly-touted recruits -- junior end Eddie Jones, freshman end Alex Okafor, senior tackle Lamarr Houston, and redshirt freshman end Dravannti Johnson -- will need to step up and account for the losses of ends Brian Orakpo and Henry Melton and underrated tackle Roy Miller.
• Since the return of underappreciated Mike Riley as head coach of Oregon State, the Beavers have given up more than 335 yards per game just once, in 2005. OSU lost a boatload of defensive talent between 2007 and 2008, including every front seven starter, but they allowed only five more yards per game in 2008 and made a surprise run at a conference title. Riley has done a great job in Corvallis, and his success in 2008 was due in part to a great pass rush. Star end Victor Butler (12 sacks, 9.5 tackles for loss) is gone, as are end Slade Norris and tackle Pernnell Booth, but you don't win much money betting against Mike Riley, so we'll see what happens to them in 2009.
• Central Michigan certainly qualifies as the most surprising name on the list. They played a perfect recipe of surprisingly solid pass-blocking offenses, including Western Michigan (fifth), Eastern Michigan (tenth), and Florida Atlantic (12th), along with Ball State (25th), Georgia (28th), Toledo (31st) and Purdue (35th). They return three strong senior ends in All-MAC performer Frank Zombo, Sam Williams, and Larry Knight.

Overall Defensive Line Rankings

As with the offensive line rankings, we will try to equally weight LY+ and SkRt+ to account for the crazy highs and lows of SkRt+.

At first blush, Central Florida's ranking is strangely high, being that A) UCF is a Conference USA team, and B) they went a cool 4-8 last year. But here they are, returning seven of their top eight players from a line that allowed just 3.4 yards per carry and managed 30 sacks (7.5 percent raw sack rate) against a series of decent offensive lines. Defense was not the problem for the Knights in 2008 -- the blame very much goes to an offense that ranked dead last in the country in Close S&P+, scored 14 points or less seven times, and averaged just 16.6 points per game. If the offense improves (not a given), a line including strong ends Jason Geathers and Bruce Miller and tackle Torrell Troup (the three combined for 39.0 sacks/tackles for loss) could lead UCF to a decent bounce-back season.

Meanwhile, one of the primary storylines for Penn State has been replacing star receivers Deon Butler, Jordan Norwood, and Derrick Williams, but if the Nittany Lions are going to make a Big Ten title run, they will need to quickly find a couple of fine replacements for ends Aaron Maybin (20.0 sacks/tackles for loss) and Maurice Evans, not to mention tackle Josh Gaines. Penn State usually produces good playmakers on the line, and obviously that will need to continue.

The Playmakers

Defensive End

With clearly no way to chart every FBS game, there will never be the same level of data at the college level as there is at the pro level. There is just no way to look at how often defensive players made plays when they were on the field, which will certainly hinder analysis to some degree. But that's not going to stop us from giving it a shot.

So how do you go about evaluating individual defensive performers at the collegiate level when there is no way to account for how many plays a given defender actually played? Start with the basics, which in the case of Varsity Numbers are success rates and EqPts.

Using our favorite Varsity Numbers measures for evaluating individual defenders, we can go in two different directions:

1) We can simply add up the number of "successful" tackles (i.e., tackles that resulted in an unsuccessful play for the offense) a player made and consider that the rough start for a "playmaker" measure.

2) We can take the fantasy football approach. You know how in fantasy football, when individual defenders are used, you get 1 point for a solo tackle and 0.5 for an assist? What if we gave 1 point for every "successful" tackle and 0.5 for every unsuccessful one? After all, a player should get credit for even unsuccessful tackles, as technically they prevented a touchdown, right? One of the most impressive plays I ever saw was when Missouri defensive end Stryker Sulak chased down Texas A&M speedster Michael Goodson 43 yards after Goodson caught a deflected pass and raced down the left sideline unimpeded. It was one of the best plays Sulak ever made, and Option 1 would not give him any credit for it.

So with that in mind, let's throw some numbers in a table and see what we get. Below are rankings tables for both defensive ends and defensive tackles from 2008. While sacks are credited in a couple of different places (they are clearly successful tackles, plus they result in a loss of EqPts), other important things like forced fumbles and quarterback hurries are not in the end, they will need to be included in the equation. But we're keeping it simple at the moment.

Here is a description of the columns:

Adj. Tkl and Adj. Tkl Rk (Adjusted Tackles and Rank): This is the "adjusted" total of tackles, in which 1 point is given for a successful tackle, 0.5 for unsuccessful.

Total Success and Success Rk (Total Successful Tackles and Rank): This is simply the number of successful tackles the player made.

Def. S&P (Defensive S&P): For fun, let's also take a look at the S&P value for plays in which the given player made a tackle.

Ret. in 2009?: Self-explanatory. Are they back in college in 2009?

Here are the six ends who received the most All-American mention in 2008, along with their Adjusted Tackles ranking: Oregon's Nick Reed (13th), TCU's Jerry Hughes (28th), Penn State's Aaron Maybin (48th), South Florida's George Selvie (59th), Texas' Brian Orakpo (88th), and Georgia Tech's Michael Johnson (94th). Anybody who saw Orakpo play knows how dominant he was, even though he didn't rank high on this list. Clearly this is a starting point for rankings rather than an end point. Still, it bears mentioning that both Oregon and Utah had multiple ends on the list.

Defensive Tackle

In football, some of the best defensive tackles in the game do not make that many tackles -- their job is to take on as many blockers as possible to free up others to make the tackle. Of course, no matter how big you are, you still need the potential to make plays if you're going to get doubled up and free up your linebackers. In the end though, making plays is but one of your jobs.

Regardless, let's take a look at the best pure playmakers from the tackle position and see what kind of list we have.

While he may have faced some of the same struggles as Nebraska's line as a whole (i.e., big-play performance, but not every-play performance) Ndamukong Suh made far more plays than any other defensive tackle in the country. He made 11.5 more successful tackles than anybody else on the above list, and only one end (Jammie Kirlew) made as many plays as he did. That's very impressive. Plus, it doesn't even take into account the two huge interceptions for touchdowns that he pulled off in key moments against Kansas and Colorado. If he comes out in 2009 and doesn't get pushed around quite as much in the running game, he will likely be close to a consensus All-American.

Here are the four major All-American defensive tackles from 2008 and their Adjusted Tackles rankings: Iowa's Mitch King (33rd), Ole Miss's Peria Jerry (88th), Oklahoma's Gerald McCoy (214th), and Alabama's Terrence Cody (462nd). Playing at around 385 pounds last year, Cody was a Gilbert Brown-esque space eater and one of the more feared tackles in the game, even though he didn't make any "plays" as constituted here. Again, there is much more work to be done in this regard. But at the very least, this gives you an interesting look at pure playmakers, even if it is not a comprehensive look at the best linemen in the game.

One last point of interest: It's interesting to see how disparate S&P is among all of these high performers. Some made a lot of plays downfield, leading to higher S&P, while others only made plays close to the line of scrimmage. A low S&P can obviously be seen as a good thing, but in some ways so can a high S&P. No clear correlation between individual S&P and good performance here.

As always, feedback is welcome. What stats would you use to evaluate defensive linemen?

Posted by: Bill Connelly on 12 Aug 2009

3 comments, Last at 13 Aug 2009, 7:57am by Bill Connelly