by Aaron Schatz

Let's continue our series presenting various 2011 stats from the multitude of Football Outsiders spreadsheets. Last week, we looked at broken tackles from the offensive perspective. Today, we'll look at it from the defensive perspective.

(Note: Before we get started, a clarification from last week's piece. I noted last week that Michael Vick had 17 broken tackles escaping sacks, more than twice as many as any other quarterback. After going back and doing a bit more cleaning of data, I have to adjust that statement a bit. Four plays we had listed as broken tackles by Tim Tebow were actually "Houdini" plays because Tebow broke the tackles behind the line of scrimmage on pass plays. Well, by "pass plays" we mean they started as pass plays and were pass plays for at least one or two seconds. So Tebow now has 12 "Houdinis." Tebow and Vick are still tied at 22 total broken tackles, the most for quarterbacks.)

Broken tackles are a stat from game charting, not from the standard play-by-play. We define a "broken tackle" as one of two events: either the ballcarrier escapes from the grasp of the defender, or the defender is in good position for a tackle but the ballcarrier jukes him out of his shoes. If the ballcarrier sped by a slow defender who dived and missed, that didn't count as a broken tackle. We only measured broken tackles for standard plays; volunteers didn't have the time to track them for all special teams plays.

The resulting numbers are subjective, obviously, but there were over two dozen charters involved, so no team's numbers could be overly slanted because of the bias of a single specific charter. We know that there are a other groups on the Web who track broken tackles, and because of the subjectivity, their numbers won't be exactly the same as ours. Given the mistakes that are easy to make when marking players off of television tape, a difference of one or two broken tackles isn't a big deal. But looking at the players with the most and fewest broken tackles does a good job of showing us which defenders were able to wrap up and which ones got run over or faked out by a great lateral move.

We can also look at broken tackle rate. For each defender we compared broken tackles to the total of broken tackles and solo tackles. We decided not to include assists, because a missed assist is not usually something we would mark as a missed tackle opportunity -- after all, another defender is getting a successful tackle at the exact same time. However, we did remove special teams tackles so we were only looking at defensive plays.

Here are all the players that our game charters recorded with 10 or more broken tackles in 2011:

St. Louis safety Darian Stewart paces the league with 19 broken tackles by our count, but some sort of special prize has to go to Tanard Jackson, who we counted with 16 broken tackles in only 10 games. A lot of the same players repeated at the top of this list for 2009 and 2010, but there were only five players with more than 10 broken tackles in both 2010 and 2011: Barber, Griffin, Levy, Martin, and Mikell. Part of the reason why there are so few repeaters is that many of these players didn't see the field as much in 2010. Stewart was primarily a special teamer as a rookie, although he had three broken tackles with only 15 solo tackles on defense. Jackson only played two games in 2010 due to suspension and injury. Eric Wright and Justin Babineau weren't starters, one reason they had only three broken tackles apiece.

If very few players had lots of broken tackles in both 2010 and 2011, what happened to the players who led the league in broken tackles two years ago? Adrian Wilson's total of 16 broken tackles now looks like a real fluke between 2009's two and 2011's six. Tennessee linebacker Will Witherspoon dropped from 15 broken tackles to five, Arizona linebacker Paris Lenon dropped from 14 broken tackles to three, and Detroit linebacker Stephen Tulloch dropped from 13 broken tackles to three. Arizona safety Kerry Rhodes went from 11 broken tackles in a full season to zero in half a season.

Now let's look at the highest and lowest broken tackle rates. First, here are the best and worst rates for linebackers, with a minimum of 50 tackles:

If you want to see evidence of the decline of the Tampa Bay defense, check out Quincy Black's broken tackle rate. In 2010, Black had only two broken tackles with 53 tackles, a 3.6 percent rate. Last year, Black had the worst broken tackle rate of any linebacker with at least 50 tackles.

Michael Boley's one broken tackle in 2011 matches his one broken tackle in 2010. Yet you never really hear Boley's name mentioned when analysts talk about the best tacklers in football. I'm surprised to see Philip Wheeler so high given the long track record of poor tackling by Colts defenders. (Wheeler signed in Oakland as a free agent this offseason.) I'm a lot less surprised to see Patrick Willis' name in the top ten. He's had only 11 broken tackles total in the three years we've been tracking the stat, despite making more plays than almost any defender in football.

Now, let's look at the highest and lowest broken tackle rates for defensive backs, with a minimum of 40 tackles:

Apparently, the Carolina defensive backs were as bad at tackling as the linebackers were good. Quality tackling in the secondary is a big reason why the mostly-terrible New England defense could often get away with a "bend but don't break" style. Players like Jabari Greer, Johnathan Joseph, and Aaron Ross are good examples of how coverage ability doesn't seem to have much correlation with tackling ability. Same goes for Asante Samuel (8 broken tackles, 31 tackles, 20.5 percent rate). Carlos Rogers, at least last year, was an exception, as was Darrelle Revis (2 broken tackles, 45 tackles, 4.3 percent rate).

And file under odd: Sabby Piscitelli, who led our broken tackle count in 2009, had only one broken tackle in 2010 and 2011 combined.

Defensive linemen don't make anywhere near as many plays as linebackers and defensive backs, so there aren't a lot of linemen with more than two or three broken tackles. Dometa Peko of Cincinnati and Jason Jones of Tennessee led our count with six broken tackles apiece, a little bit of a surprise since we counted zero broken tackles from each player in 2010. Jones is really the broken tackle king for linemen since Peko made twice as many tackles as Jones did. Cliff Avril had five broken tackles last year and leads all defensive linemen with 10 broken tackles over the two-year period of 2010-2011. Lots of linemen had zero recorded broken tackles, including Chris Canty, Andre Carter, Jason Babin, Geno Atkins, and Brandon Mebane (with 46 tackles, the most among players with no broken tackles in 2011).

Finally, here's the list of broken tackles by all 32 defenses. Two defenses were far, far ahead of the rest of the league when it came to broken tackles: Tampa Bay (9.0 percent of plays) and Philadelphia (8.1 percent of plays). No other team was above 6.5 percent. When you see such a big gap between these two teams and the rest of the league, it makes you wonder if we had an issue where the charters doing Tampa Bay and Philadelphia were too relaxed in their subjective determination of what counted as a broken tackle. But I don't think this was the case. If this was an issue with the charters, we would expect Tampa Bay to be high in both offensive and defensive broken tackles, but they were just average on offense. Philadelphia actually was very high on both sides of the ball, but that can't be an issue with a single charter because we have more game charters who are Eagles fans than any other team. That means that they rotated who got to chart the Eagles and who had to chart some other team, and the Eagles games were well spread-out among multiple charters. In addition, Tampa Bay and Philadelphia having a lot of broken tackles makes subjective sense. The Eagles were known for their bad tackling all year, and the Bucs were known for completely giving up on the season.

San Francisco and the New York Giants had the lowest rates of broken tackles on defense.