NFL Combine 2013 Tale Of The Tape: Making Sense Of The Defensive Tackle Numbers

You know the drill by now: for this position review, just like we did for the offensive linemen on Sunday and the defensive ends on Tuesday, we'll look at how the defensive tackles performed against expectations in the various drills, and then look at a handful of metrics that allow us to perhaps understand the individual results better.

We'll start by looking at how the DTs fit the following target test results for Combine measurements:

The next table shows all the basic measurements for the defensive tackles at the Combine. The 'Targets Met" column on the far right shows how many six target measurements a prospect was able to meet. For your convenience, the table is sortable, so you can sort and re-sort to your heart's delight. "Rank" indicates where a player is currently ranked on the CBSSports big board.

Defensive Tackles, 2013 Combine measurables (click column header to sort)

The table shows so many DNPs that it's a little hard to make an accurate read. It looks like the visibly slimmed down Sheldon Richardson and Sharrid Floyd did well in the drills that they participated in.

The two players that stand out here are Jared Smith out of New Hampshire and Nicholas Williams out of Samford. Both are currently ranked as third day picks but stood out among this group of defensive tackles on the strength of their athleticism.

The thing to keep in mind here though is as you look at the prospects that did particularly well, they're all bunched pretty tightly around 300 pounds. The heavier guys understandably didn't do quite as well in these drills as their somewhat lighter colleagues. A prospect like Brandon Williams may have had difficulties hitting the athletic markers at 335 pounds, but he didn't have any difficulties being a highly productive defensive tackle in college.

To get a better handle on that, we'll look at a handful of other metrics to assess our prospects. The definitions below are repeated for readers who may have missed the previous post; skip it if you've read it before.

1. Production ratio: [(SACKS + TACKLES FOR LOSS) / NUMBER OF COLLEGE GAMES PLAYED = PRODUCTION RATIO]

This number measures the playmaking potential of front seven players coming out of college. In our table below, the number is based on the last two years of a players' college production. What you want in a Production Ratio is a score of 1.0 or better. Effectively, a score of 1.0 says that a player recorded one splash play in the defensive backfield per game.The higher the number, the better.

2. Kirwan Explosion Index: [BENCH PRESS REPS + VERTICAL JUMP + BROAD JUMP = EXPLOSION NUMBER]

First proposed by Pat Kirwan, this is a simple addition that adds up the number of bench press reps with the broad and vertical jump values. What this number gives you is an idea of the explosive strength of a lineman. An explosion number over 70 is considered a very good result, with anything above 65 still being good.

3. Explosive Power: (VERT+3.5*BROAD)*(WEIGHT/HEIGHT)/3000

This is a metric that was developed, as far as I know, by Tony Wiltshire, a writer for BuffaloBillsDraft.com. Where about half of Kirwan's Explosion Index (KEI) is made up of upper body strength, the Explosive Power metric focuses on lower body strength relative to a player's physique. This metric gives you a good idea of how strong a lineman is off the snap and the amount of pure physical force he can generate out of his legs. A value over 1.05 is elite, a value over 1.0 is excellent, and anything over 0.95 is still very good.

4. Lateral Agility: [40-YARD DASH TIME - 20-YARD SHUTTLE = LATERAL AGILITY]

This number uses the differential between the 40-yard dash time and the 20-yard shuttle to get a better feel for the lateral agility of a player, as the differential provides information beyond simple long speed and short-area quickness. Generally speaking, a player who notches a .50 or better is considered to have outstanding lateral agility, a quality highly sought after in interior linemen who usually operate in very tight spaces.

5. Speed Score: [(WEIGHT * 200) / (40-TIME ^ 4) = SPEED SCORE]

Not all players are created equal, and it doesn't make a lot of sense comparing 40-times of players who may have a weight difference of 60 pounds. The Speed Score takes into account both a player's time in the 40-yard dash as well as his weight. The ratio was initially developed for running backs, but works just as well for DTs. A good score for an interior defensive lineman is 95 or higher.

Defensive Tackles, 2013 Combine additional metrics (click column header to sort)

With NFL fans caught up in the excitement of the Combine, sometimes it's easy to forget that a one-day workout session cannot trump four or more years of game film. Particularly in cases where freakish athleticism does not match on-field production, teams will need to take a closer look at why that is the case. It's not necessarily a red flag, but it warrants a closer look. Similarly, one bad day of working out will not discount consistent production at a high level in college.

Couple of observations about the numbers:

1 vs 3: Some of the prospects in the list above will be 1-techniques, some will be 3-techniques. If you want a penetrating 3-technique, you'll want a guy with a good track record of production in college. And if you look at the top guys in the table above, most didn't have a spectacular production ratio. The only standouts here are Brandon Williams and Kawann Short. There's a risk that most of the guys here will be average 3-techniques. They may be good 1-techniques, but I'm hedging my bets on the 3-techniques.

The Marcus Spears risk. At his pro day, Marcus Spears ran a 5.05 forty, had a 31 inch vertical jump and a 4.44 20-yard shuttle, all at 307 pounds. Additionally, Marcus Spears had a 1.60 production ratio (28 games, 15 sacks, 30 TFLs) over his final two seasons at LSU. Compared to this year's draft class, Spears would have been one of the top prospects. And ultimately, that's the risk with this group: Will they be better than Marcus Spears?

Late round prospects? Jared Smith and Nicholas Williams have an average production ratio, but they did hit on three of the four other metrics. Their athleticism is intriguing, but I know next to nothing about either prospect. I guess I'll have to do some reading up on those two.

Incomplete: Not a single one of the top seven prospects as ranked by CBSSports completed all of his drills. That makes this a tough class to read and project, so we'll have to look at the Pro Days to perhaps get some more numbers on these linemen. Overall though, I'd be wary of this draft class. I don't share the feeling that this is the best defensive line class in a long time - at least not based on what they showed at the Combine.

In the next installment of our look at the Combine results, we'll look at how the safeties performed.