In this week's Varsity Numbers, Bill Connelly revisits some measures and concepts: Adjusted Scores, Covariance, and momentum (or whatever you choose to call it).
05 Jan 2007
by Aaron Schatz
Dallas is falling apart. The quarterback is a mess, and the pass defense is a disaster. In other words, over the last five weeks, the Cowboys have resembled ... what the Seahawks have looked like the entire season.
The Giants have struggled for two months now. Isn't there anyone in the NFC who didn't back into the playoffs? Oh, hello there, Eagles.
For those who may be visiting this site for the first time to read this preview, we explain our stats at the bottom of the page, or click this link. Each preview also includes a link to the game discussion thread for that game. We're doing separate game discussion threads for each game this year, rather than combining both games on the same day like we did last year.
Note: When I wrote this preview for the New York Sun, I didn't do it in the "When Road Team Has the Ball/When Home Team Has the Ball" format and I don't feel like re-writing it. I hope nobody minds.
A month ago, the Dallas Cowboys were the hottest team in the NFL. Four straight wins put them on top of the NFC East with an 8-4 record. The defense was strong, stuffing the run and pressuring opposing quarterbacks. The offense was firing on all cylinders, and it seemed like quarterback Tony Romo could do no wrong.
So how did we get from there to here? The Cowboys went 1-3 over the last four weeks, gave up the division lead, and backed into the playoffs because the NFC couldn't even field six teams with winning records.
The negatives first appeared in the Cowboys' 23-20 win over the Giants in Week 13. Until that game, the Cowboys had given up 20 or more points in four different games. Including the Giants game, the Cowboys gave up at least 20 points in all five of their December games.
Through Week 12, the Cowboys ranked fourth in defensive DVOA. Since Week 13, they rank last.
The run defense has softened somewhat, but the real problem is the passing game, where suddenly the Dallas secondary can't stop anybody. The Cowboys allowed just 5.7 net yards per pass through 12 weeks, but 7.8 net yards per pass in the last five games.
Dallas isn't just falling apart on defense, however; Romo's early stardom faded as opponents learned his weaknesses. Romo gets rattled and can make terrible decisions under pressure. This problem was exacerbated by his early success because he got used to making mistakes without feeling the consequences.
Romo averaged 8.6 net yards per pass through Week 12, but he's getting just 6.7 net yards per pass since, taking more sacks and throwing more interceptions.
All of this sounds like a recipe for Dallas to go one-and-done, except for one thing: the Seahawks have the same problems, and they have them worse.
Seattle may be the first Super Bowl loser to return to the playoffs since 2000, but that doesn't make them a good team. The Seahawks are 9-7 thanks to an easy schedule and good fortune in a few close wins. DVOA ranks them 27th on offense and 20th on defense.
Seattle's offense was supposed to rebound when running back Shaun Alexander and quarterback Matt Hasselbeck returned from injuries, but that never happened. Week 12's win over Green Bay was the first time since early in the season that both players were in the lineup. At that point in the season, the Seahawks averaged 4.0 yards per carry and 5.5 net yards per pass (-10.9%, 24th in the NFL).
In the last six games, with Hasselbeck and Alexander both healthy, the Seahawks have averaged 4.1 yards per carry and 5.4 net yards per pass (-12.6% DVOA, 25th in the NFL). Hasselbeck, in particular, just doesn't seem to be seeing the field right. It isn't just that he's throwing more interceptions -- 15 to tie his career high, despite only playing 11 1/2 games. They're monumentally stupid interceptions, throwing to guys who are completely covered.
The injury problems on offense go deeper than just those two players. Injured players have been shuffled in and out of the offensive line all year. Two of Hasselbeck's top three wideouts, Darrell Jackson and D.J. Hackett, may miss this week's game with injuries.
Of course, this is nothing compared to the injuries in the secondary. Seattle will face Dallas, which may have the best receivers in the NFL, with three of its top four cornerbacks out. Terry Glenn and Terrell Owens will be covered by rookie Kelly Jennings and Jordan Babineaux, who was so bad last year as a cornerback that the Seahawks had converted him to safety.
The other issue when Dallas has the ball is the running game, although this may not be as big a problem as Seattle fans think. The Cowboys are good running the ball with Julius Jones and Marion Barber -- although, as we've pointed out before, not in that order -- and if you've watched Seattle games recently, you have a mental picture of the Seahawks missing a bunch of tackles. But DVOA says they really aren't that bad against the run, just average. They rank 23rd, but the teams between 15th and 23rd are all pretty closely packed together. Dallas has an advantage, but don't confuse it with the advantages that the Kansas City, New England, and Indianapolis running games all have over awful run defenses in the other conference.
One more note: Look at that game-by-game DVOA chart on Seattle. The Seahawks have no dominating wins this year. They basically have one dominating half, the first half against New York in Week 3. They also have five games below -40% DVOA. The Cowboys have six games with higher ratings than ANY Seahawks game, and even during their recent slide, only one game below -40% DVOA.
Not much to say. Mat McBriar punts the ball a long way but the Dallas coverage isn't very good. Seattle is above-average in every phase of special teams but spectacular in none of them. Seattle's punting game is the one thing that's better this year than it was during their Super Bowl year. Thanks, Ryan Plackemeier!
The Seahawks pride themselves on having a particularly strong home-field advantage, but the Cowboys are healthier on defense and better on offense. Despite their late-season struggles, they are the most likely of this weekend's road teams to move on.
When Donovan McNabb went down for the season, most people gave up on the Eagles. But Jeff Garcia... blah blah blah... You all know how this goes, right? Our version: The Eagles never dropped out of the top 10 in DVOA, and they were always better than people gave them credit for, because they lost some of those early games on weird, weird bad luck. But we didn't think Garcia would be able to keep the offense going either. There's a reason we felt that way. Look below at the Philadelphia game-by-game graph. Wow, is that consistency -- except for two terrible games that stick out like a pair of sore thumbs on a very tired Antonio Alfonseca. Those are Garcia's first two games. After that -- possibly thanks to the magical power of Football Outsiders' first-ever official press box appearance -- the Eagles beat Carolina on Monday Night Football, and ever since they've been the same team that they were back before McNabb got hurt. They have a positive DVOA in 14 of 16 games this season.
Oh, and the Giants completely collapsed over the second half of the season, blah blah blah... you know that part too. Can you tell this is the fourth playoff preview I'm writing over a 24-hour period, and I'm getting a little punch drunk? Anyway, as much as people want to just hand this game to the Eagles, do remember that these teams just played a couple weeks ago, and the Giants were winning 22-21 with seven minutes left.
Stop me if you've heard this one before: Eli Manning played better over the first few weeks when the Giants went 6-2 than he did in the last few weeks when they went 2-6. DVOA backs up conventional wisdom on this one; other than one strong game (against the Cowboys in Week 13, the start of their defensive demise) Manning has been much worse since Amani Toomer got injured halfway through the year. In Weeks 1-9, Manning had 6.2 net yards per pass, and a DVOA of 12.0%. In Weeks 10-17, he's gaining 5.0 net yards per pass with a DVOA of -14.9%. (The interceptions are the same, however: nine in each half of the season.)
Manning's worst habit is depending on the same receivers over and over. Without Toomer, that left him with just Plaxico "The Living Offensive Pass Interference Flag" Burress and Jeremy Shockey, and he may not even get Shockey this weekend -- the tight end missed the last game of the year and is questionable for this one with a left ankle injury. Before Toomer's injury, Manning threw 12 passes per game to wide receivers other than Burress. Since Toomer's injury, Manning has thrown just six passes per game to wide receivers other than Burress.
The Giants' running game is better than their passing game, and the Eagles' run defense is not as strong as their pass defense. Wow, this is really getting to be a pattern this weekend, isn't it? That Tiki Barber kid is pretty good, but a succession of useful 4-6 yard runs is more likely than Barber breaking off the kind of absurd highlight runs that he had against Washington in the final game of the regular season. The Eagles rank 21st in Adjusted Line Yards but sixth in the percentage of rushing yardage that came past 10 yards. Barber is best running around the ends, and the Eagles are stronger defending those runs than they are defending runs up the middle. But it isn't like the Giants are bad running up the middle, so this doesn't seem like it will be a huge problem.
The Eagles' defense stiffens in "power" situations (third/fourth down with 1-2 yards to go), so Brandon Jacobs might not be quite as money as usual. However, the Eagles are actually below average against the run on third down -- because they've given up some huge scrambles and draw plays on third-and-long. Manning isn't a running quarterback, but Barber can certainly thrive on draws. Screens may not work though, despite the Eagles' love of the blitz; they ranked second in DVOA on passes to running backs.
The Giants are excellent in the red zone, but so is the Eagles defense.
Toomer's final game was also the last game where Michael Strahan was healthy, and so the decline of the Giants' offense was joined by a simultaneous decline on the defense:
|Weeks 1-9||Weeks 10-17|
|NYG defensive DVOA vs. pass||-13.8%||4||16.6%||27|
|NYG defensive DVOA vs. run||-15.1%||11||2.3%||14|
(By the way, if those rush defense DVOAs and ranks seem strange, it's because rushing league-wide was much better in the second half of 2006 than it was in the first half of 2006.)
The Eagles' offense has been near the top of the league all year except for that two-game bump when Garcia first took over as quarterback. Everybody knows that the Eagles don't run as often as other teams, but people don't often realize how good the Eagles are when they do run. Brian Westbrook averaged 5.1 yards per carry this year, while Correll Buckhalter averaged 4.2 yards per carry -- rarely breaking a long run, but also rarely getting stopped for a loss or no gain.
Michael David Smith does such a good job talking about Philadelphia's deep passing game that I might as well point you to this article he wrote over on FOXSports.com. Those deep passes are big trouble for the Giants. Their cornerbacks aren't that good, but their safeties are really bad. Obviously, our game charting numbers for 2006 are really preliminary, including only games from Weeks 1-14. But based on those early numbers, Kevin Dockery allowed 12 yards per pass when he's marked as the defender in coverage -- #1 among all players with at least 30 charted passes. Will Demps' 9.8 is eighth. Both have Stop Rate of 36%, and the only defensive back worse than that is Travis Fisher of St. Louis (again, minimum 30 charted passes through Week 14).
The other problem with bad safeties? Covering tight ends. The Giants ranked 31st in DVOA on passes to tight ends, so L.J. Smith could do some big damage.
The Eagles also have an advantage in some of the most important situations. The Eagles' offense ranks fifth in the red zone, the Giants' defense 25th. The Eagles rank first in "close and late" situations (second half, score within 8 points) while the Giants rank 22nd.
Although the Eagles bounced back from last year's debacle, the special teams did not. This is the first year in a long while where the Eagles special teams have struggled for the entire season. David Akers hasn't done well on field goals this year, although he's still been strong on kickoffs. (By the way, that poor FG/XP number is not all Akers; it includes a bad snap aborted field goal.) If each element of special teams plays according to form, the Giants will have a field position advantage when they punt, and the Eagles will have a field position advantage when they kick off.
It probably sounds like I'm predicting a huge Philadelphia victory here, but remember that being a consistent team has a downside. Leaving aside those first couple games while Garcia was getting used to starting again, the Eagles haven't played any really bad games -- but they also haven't really come out and blown anyone away, except maybe for the Cowboys on Christmas Day, and even that game was still just 16-7 with seven minutes left. If Tiki Barber takes over and Philadelphia's tackling problems return, if Eli Manning shakes out of his funk and Jeremy Shockey is able to play, if the safeties don't royally screw up and a couple of bounces go New York's way -- there are a lot of ways I can imagine the Giants winning this game. But the more likely scenario is that the game is close at halftime, and the FOX guys all talk about how surprised they are that the Giants are competitive -- and then the Eagles pull away in the second half and win by a touchdown or two.
DVOA (Defense-adjusted Value Over Average) breaks down each play of the season and compares it to the NFL average based on situation and opponent. You'll find it explained further here. Since DVOA measures ability to score, a negative DVOA indicates a better defense and worse offense, and a positive DVOA indicates a better offense and worse defense.
Each team is listed with DVOA for offense and defense, total along with rush and pass, and rank among the 32 teams in parentheses. (If the DVOA values are difficult to understand, it is easy to just look at the ranks.) Red zone DVOA is also listed. These numbers are all regular season only.
WEI DVOA is WEIGHTED DVOA, which is based on a formula which drops the value of games early in the season to get a better idea of how teams are playing now (explained here). This is the same formula used in this week's FOXSports.com power rankings.
SPECIAL TEAMS numbers are different; they represent value in points of extra field position gained compared to NFL average. Field goal rating represents points scored compared to average kicker at same distances. All special teams numbers are adjusted by weather and altitude; the total is then translated into DVOA so it can be compared to offense and defense.
Each team also gets a chart showing their performance this year, game-by-game, according to total DVOA. In addition to a line showing each game, another line shows the team's trend for the season, using a third-power polynomial trendline. That's fancy talk for "the curve shifts direction once or twice." Note that even though the chart appears in the section for when each team has the ball, it represents total performance, not just offense.
63 comments, Last at 07 Jan 2007, 11:17pm by Charles the Philly Homer