Can the Cowboys Survive without Sean Lee?

Sean Lee will likely miss the 2014 season with a torn ACL, leaving the Cowboys without their standout linebacker.

For the past three seasons, the Dallas Cowboys have been in football limbo, finishing 8-8 all three years.

The Cowboys would like nothing more than to buck that trend, but recent news about middle linebacker Sean Lee might change the things in the wrong direction.

Lee suffered a serious knee injury in late May, thought to be a torn ACL, and his 2014 season is already in jeopardy. He's now missed significant time over the past two seasons, his third and fourth years in the league. In 2012, Lee played in just 6 games, and last year, 2013, he played in 11.

Lee played in Dallas' first 10 games last year, as well as the team's Week 13 tilt against the Chicago Bears.

Through the first 10 weeks of the season, Dallas was surprisingly decent on defense in terms of our Adjusted Defensive Net Expected Points (NEP) metrics, which shows the amount of expected points a team allows, adjusting to reflect strength of schedule. If you want a more detailed explanation, click the link.

The adjusted piece is important, because the schedule was brutal from an opponents' offense perspective - Dallas faced San Diego, Denver, Philadelphia, Detroit and New Orleans during their first 10 games a season ago. Each of those teams were top eight offenses according to our metrics last year. So while their raw numbers looked pretty dreadful, the advanced metrics accounted for the tough offenses they faced.

At the end of Week 11, after the team's bye week, the Cowboys had solid marks in two of the three primary per-play adjusted metrics: Adjusted Defensive NEP, Adjusted Defensive Passing NEP, and Adjusted Defensive Rushing NEP.

When fixed for strength of schedule, the Cowboys allowed just 0.01 expected points per play on defense, -0.01 on passing plays, and 0.05 on rushing plays.

The Adjusted Defensive NEP per play (0.01) ranked 13th in the league, and the Adjusted Defensive Passing NEP per play (-0.01) ranked 9th (which seems crazy considering how they finished the season). However, the Adjusted Defensive Rushing NEP per play (0.05) was a lowly 27th in the league at the time.

When Lee began to miss time and played in only one game after Week 11, things for the Cowboys went downhill quickly.

TotalsAdj. Def NEP/PlayRankAdj. Def PNEP/PlayRankAdj. Def RNEP/PlayRank
Weeks 1-110.0113th-0.019th0.0527th

The defensive metrics dropped substantially for the Cowboys aside from the rushing mark, which was already bad to begin with. Instead, when the Cowboys lost their defensive leader, things diminished quickly for what was actually a pretty effective unit overall.

We can also look at the differences in divisional matchups, as Lee played in the Cowboys' first three divisional games (against the Giants, Eagles, and Redskins) but missed the second game against each team.

Here's how the Cowboys fared with Lee in those games.


As you can see, the Week 1 debacle from the Giants on the ground got the Cowboys a great tally in terms of defensive rushing, denying the Giants 13.19 points from their ground game thanks to costly turnovers. They did give up 11.27 more points than expected through the air, but this, along with a fairly generous game allowed to Washington's rushing game, was the only poor measure resulting from the NFC East battles with Lee defending the pass.

You may also recall the drubbing of the Eagles, a game in which Philadelphia scored only three points and quarterback Nick Foles finished just 11-of-29 for 80 yards, while Matt Barkley came in to throw three interceptions (one of which went to Lee). This shows up nicely in the metrics, as the Cowboys stifled the Eagles and denied them over 20 expected points in the game.

Per the metrics, the Cowboys defense was quite good against their divisional rivals, and they racked up three wins from these meetings.

Without Lee, though, things didn't go quite as well.


The Cowboys were caught in three tight games with the divisional foes this time around. After outscoring the division 84-50 with Lee, the Cowboys outscored the three teams just 70-68, but did win two of three games.

The metrics, though, indicate that the Cowboys allowed slightly more points than they should have, and really only had a stellar game against the horrible Eli Manning, who went 16-of-30 for 174 yards and 2 touchdowns.

Although the team was just 5-6 with Lee including the Bears game in Week 13, there's a noticeable decline in defensive performance without Lee. Now that the team has lost defensive staples DeMarcus Ware and Jason Hatcher, things are looking really sticky in Big D.

Justin Durant might take over at middle linebacker for Lee, whose 6.1 tackles per game paced him to finish in the top 10, or rookies Anthony Hitchens and Will Smith might play a role in filling the void, though both were drafted as outside linebackers.

But whoever takes on the role at middle linebacker will have a lot of work to do to fill Lee's leadership position in the Cowboys defense. If the Cowboys can somehow muster Defensive NEP marks similar to the ones in the first 11 weeks of the season, then they could potentially hit the nine-win mark. However, the Cowboys now boast a defense that's without Lee, Ware, and Hatcher.

If Dallas can't figure out how to replace the trio, the decline in defensive efficiency experienced this season means that 8-8 might be wishful thinking.