by Aaron Schatz

Welcome to the undercard! There's no question that the AFC final four is superior to the NFC final four this season, but Philadelphia and New Orleans are two talented, evenly matched teams. Chicago and Seattle, on the other hand, looks like the Battle of Who Can Implode Less.

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 [1]. 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.

Philadelphia at New Orleans

During the game, please join the discussion in the Eagles-Saints Game Discussion Thread [2].

Also of interest: An October Every Play Counts on the Saints defense [3], this article on how the Saints should use Reggie Bush [4], and Any Given Sunday columns on the Eagles' Christmas win over Dallas [5] and the Saints' loss to Washington [6] in Week 15.

A quick note: This year we got away with just two Week 17 games where playoff teams used second-stringers for most of the game, but the two teams that did were Philadelphia and New Orleans. Philadelphia actually played pretty well with its backups, but the New Orleans numbers are slightly depressed by the Jamie Martin Experience.

Like the other NFC semifinal, this game is a rematch of one from the regular season. But that game was not a blowout; it was a hard-fought, well-played battle, taken 27-24 by New Orleans thanks to a last-second field goal. The Saints and Eagles are as evenly matched now as they were then, and this second game will probably end up just as close.

WHEN THE EAGLES HAVE THE BALL

Both Philadelphia and New Orleans rank among the five best offenses in the league this year, but they were not equal on defense. Philadelphia ranked 11th in DVOA, New Orleans 19th. However, this doesn't necessarily mean that Philadelphia has a clear edge when their offense is on the field.

Philadelphia had one of the most consistent offenses in the league this year, faltering for just two games when Jeff Garcia first took over as quarterback for the injured Donovan McNabb. The Saints, however, had one of the least consistent defenses in the league. They shut down some teams (Falcons, Cowboys, Giants) while other teams -- mainly those from the AFC -- walked all over them. The benefit of inconsistency is that below-average performance on the season doesn't necessarily mean below-average performance in your next game.

The Eagles have a more balanced offense than most fans realize. While they prefer to pass, they are extremely efficient when they run, and Brian Westbrook averaged 5.1 yards per carry this year. New Orleans' main weakness against the run comes on the right side of the defense. Opposing running backs gained 5.1 yards per carry on runs listed as left end or left tackle (4.7 adjusted line yards), compared to 4.4 yards per carry on other runs (4.0 adjusted line yards).

The Saints' pass defense got an extremely imbalanced performance from the secondary [7] during the second half of the year. Starter Mike McKenzie and nickel back Jason Craft played very well, but Fred Thomas was consistently burned by speedy receivers like Chad Johnson, Terry Glenn, and Antonio Bryant. Over the full season, the Saints were the worst defense in the league [8] against opposing number one wideouts.

The Eagles didn't show much of their long passing game against the Giants last week, but they do love to throw the ball deep, with fast receivers like Donte' Stallworth, Reggie Brown, and Hank Baskett. Stallworth was injured when these teams first played, but Brown burned the Saints for 121 yards and a touchdown on six catches. Westbrook may not get as involved in the passing game as usual, however, because the Saints are one of the top teams at stopping passes to running backs. (Likewise, the Saints love to throw to Reggie Bush, and the Eagles are also one of the top defenses against passes to running backs.)

The Eagles were the best offense in the league on first down [9] -- yes, better than Indianapolis. The passing game wasn't quite as efficient on second and third down, but the running game on third-and-long is exceptional. Westbrook is excellent on draws, and Garcia, like McNabb before him, is always a threat to run for a first down if he can't find anyone open and there's a hole in front of him. This is a big advantage for the Eagles, as New Orleans had a terrible time stopping scrambles and draws on third-and-long. Combine that with the fact that the secondary can be beaten deep, and the Saints ranked 29th in defensive DVOA on third downs.

One more interesting split for the New Orleans defense: They had the worst defensive DVOA in the league between their own 40-yard line and the 20-yard line, what we call the "front" zone. But they had the sixth-best defensive DVOA in the league in the red zone -- so we may be seeing a lot of David Akers.

WHEN THE SAINTS HAVE THE BALL

The Saints had one of the best passing games in the NFL this year. Drew Brees was an MVP candidate and he had a variety of weapons to throw to: Bush coming out of the backfield, outstanding rookie possession receiver Marques Colston, breakout speedster Devery Henderson, and the face of the Saints franchise, veteran Joe Horn.

Horn was a huge problem for the Eagles when these teams first played. He gained 110 yards and scored two touchdowns. Safety Michael Lewis made numerous mistakes trying to help with deep pass coverage against Horn; it led directly to him being benched and replaced with Sean Considine.

Horn probably won't cause so many problems this time, however. He may not even play. Horn has only played three of the last nine games for the Saints, and he is once again listed as questionable due to a groin injury.

The Eagles do have a problem, though, covering all of these good receivers without their best cornerback this season, Lito Sheppard. That leaves Roderick Hood starting opposite Sheldon Brown. If you look in Pro Football Prospectus 2006, you will see that Hood was spectacular in our game charting numbers last year, but he really struggled early in 2006. However, based on very limited charting data from this season, it does look like post-injury Hood has been far better than pre-injury Hood.

The real worry is what to do when the Saints go three-wide or four-wide. The Eagles may be excellent against passes to running backs, but that's usually a running back coming out of the backfield, not someone like Bush lining up as a receiver. The Eagles linebackers and safeties aren't really known for being great in pass coverage, and with Hood as a starter, the nickel back will be Joselio Hanson, or as he's better known on Philadelphia sports radio, "Toastolio."

Eagles defensive coordinator Jim Johnson loves to throw complicated blitzes at opponents, but that may not work so well against the Saints, who have a much improved offensive line and backs who can block. The Eagles had the league's fourth-highest adjusted sack rate [10], a stat which measures sacks per pass play adjusted for situation and opponent. But the Saints' offense had the fourth-lowest adjusted sack rate [11].

The Eagles do have problems against the run, often leaving holes with their big blitzes and struggling to wrap up on tackles. The Eagles are probably more susceptible to the straight-ahead style of Deuce McAllister rather than the shifty boom-and-bust style of Reggie Bush. The Eagles are strong against runs around the ends, but they are weaker against runs up the middle.

The run defense does stiffen when necessary, however. The Eagles stopped 47% of runs in power situations (third/fourth down, 1-2 to go), which ranked fourth in the NFL. The Saints converted just 54% of those runs, which ranked 30th.

SPECIAL TEAMS

If Bush is returning punts for the Saints, there's always the chance for a game-changing play, but otherwise, the Saints are average on special teams. 42-year-old kicker John Carney is reliable but rarely tries a field goal over 40 yards. The Eagles had poor special teams in 2006, and even reliable kicker David Akers had a tough year on field goals, although he was still one of the top kickoff men in the NFL.

OUTLOOK

This game is actually quite similar to the New England-San Diego game that will be played on Sunday. The two top franchises of the early 21st century face two franchises without many recent playoff appearances. Each set of opponents was evenly matched during the regular season, but in each game, the less experienced team has the advantage of home field and an extra week of rest. That last-minute field goal that gave New Orleans a 27-24 win back in Week 6 also makes the Saints a slight favorite in this otherwise even matchup.

Seattle at Chicago

During the game, please join the discussion in the Seahawks-Bears Game Discussion Thread [12].

Also of interest: This Every Play Counts [13] from back when the Chicago passing game was working and this Too Deep Zone [14] with ideas on how to make it work again, plus this Any Given Sunday [15] on Seattle's first loss to San Francisco.

Both Seattle and Chicago were undefeated when they first met back on October 1, and the game was hyped as a preview of the NFC Championship. Then the Bears destroyed the Seahawks 37-6, dominating every phase of the game. After that, most people were wondering if the Seahawks could even make it back to the playoffs -- and if Chicago quarterback Rex Grossman might finish the season with an MVP award.

On paper, the sequel looks to be a mismatch like the original. DVOA has Chicago as the fourth-best team in the league this year, and Seattle is 25th, by far the worst team to make the playoffs. But nobody is talking about Rex Grossman as an MVP candidate anymore -- they're talking about how many interceptions he'll throw before head coach Lovie Smith pulls him for backup Brian Griese. And even the vaunted Bears defense has declined of late, giving up at least 21 points in four straight games after giving up 21 only twice in the first 12. Chicago has a below-average defensive DVOA in those four games (4.6%). Could the Seahawks possibly pull the upset?

WHEN THE BEARS HAVE THE BALL

In the past 11 games, Grossman has barely completed half his passes, with 17 interceptions and only 13 touchdowns. But numbers don't do enough to describe just how bad Grossman is playing. He's constantly flustered by pass pressure and missing open receivers all over the field. By early December, the Chicago offense had regressed to the point where coordinator Ron Turner was calling easy short passes just to try to build Grossman's confidence [16] -- only to watch Grossman overthrow open guys in the flat, or hold the ball too long, unsure of himself.

Grossman had reasonably good games against St. Louis and Tampa Bay late in the year, but that wasn't Grossman fixing his problems; that was Grossman facing two very bad defenses.

On the surface, Seattle also seems like a bad defense that Grossman can handle, especially since they've been hit with a barrage of injuries in the secondary. There's a small chance that starting cornerback Marcus Trufant will play; otherwise, with three of their top four cornerbacks injured, the Seahawks will start rookie Kelly Jennings and Jordan Babineaux, who was so bad as a cornerback last year than the Seahawks moved him to safety. Nickel back Pete Hunter was working a desk job until two weeks ago.

But there's an important difference between the Seahawks and those other teams: the Seahawks have a pass rush. It isn't quite as strong as 2005, when the Seahawks led the league in sacks, but it's plenty stronger than the Rams or Buccaneers. Last week, the Seahawks's front four put enough pressure on Dallas quarterback Tony Romo to allow the linebackers to give the weak defensive backs help in zone coverage. And if the pass rush forces Grossman into mistakes, it won't matter who the Seattle cornerbacks are (or how talented the Chicago receivers are).

While Grossman has faltered, the running game has improved. Over the first half of the season, veteran Thomas Jones averaged 3.8 yards per carry, but he's averaging 4.4 yards per carry over the last eight games. His backfield partner, Cedric Benson, has averaged 4.7 yards per carry over the last eight games and is finally fulfilling his promise as the fourth overall pick in the 2005 draft.

Chicago runs best up the middle [11], leading the league in adjusted line yards middle/guard. Seattle's defense was average against runs middle/guard. Their strength was stopping runs on the right side of the offense [10] (sixth against runs right tackle, second against runs right end) where linebacker Leroy Hill is better against the run than the pass. Seattle's weakness was giving up long runs (32nd in the league on yards gained more than 10 yards past the line of scrimmage). Seattle showed some horrible tackling this year, and Jones and Benson are physically similar to a running back who gave the Seahawks fits, Frank Gore of San Francisco. However, Jones doesn't quite have the burst of speed that Gore does, which is why Chicago ranked only 27th in rushing yardage past 10 yards.

Even if Jones and Benson are gaining yards on the Seahawks, the Bears can't run the ball on every play. Grossman will have to throw the ball occasionally, and every time he drops back to pass, Chicago fans will hold their breath, waiting for him to do something stupid.

WHEN THE SEAHAWKS HAVE THE BALL

The Seahawks struggled at midseason when both quarterback Matt Hasselbeck and running back Shaun Alexander were sidelined by injuries, and most Seattle fans assumed the Seahawks offense would return to greatness once they both returned. But it never happened.

In the first ten games of the year, the Seahawks averaged 4.0 yards per carry and 5.5 net yards per pass (-10.9% DVOA, 24th in the NFL). Alexander returned in Week 11, Hasselbeck in Week 12 -- but still, the Seahawks averaged 4.1 yards per carry and 5.4 net yards per pass (-12.6% DVOA, 25th in the NFL) over the final six games.

Nothing changed against Dallas. Alexander gained just 69 yards on 24 carries, while Hasselbeck completed only half his passes and threw two interceptions.

Chicago's ferocious defense dominated Matt Hasselbeck when these teams first played, and defensive tackle Tommie Harris led the way. While he only had two official sacks, it seemed like Harris started every play by tossing a double team aside and ended every play sitting on top of Hasselbeck.

But Harris won't be playing this week. He suffered a season-ending injury against Minnesota in Week 13 -- and without Harris to provide pressure, the Chicago pass defense has faltered. The Bears allowed 4.6 net yards per pass with 21 interceptions in the first 12 games (-42.3% vs. pass), but 6.0 net yards per pass with only three interceptions in the final four (12.2% DVOA vs. pass). They're still getting 2.5 sacks per game, but Chicago's adjusted sack rate has dropped in half, from 6.6% to 3.0%.

While Harris is the most important injury here, he's not the only one. The Bears have also been without strong safety Todd Johnson, who himself was a replacement for starter Mike Brown. Johnson will be back this week, good news for the Bears.

But the Seahawks are also getting important players back. The most important one who missed the first Chicago game is, of course, Alexander. Quotes in the press seem to indicate that the Seahawks plan on riding Alexander to victory, but Chicago's run defense didn't decline over the last four games the way the pass defense did. On the other hand, there's a 70% chance of snow, and the last time the Seahawks played in snow, they handed the ball to Alexander roughly 40 gazillion times and he gained 200 yards.

The Seahawks are also getting wide receivers back. Bobby Engram, who missed half the season with a thyroid disease, was once again the dependable first down machine of old as Seattle's leading receiver against the Cowboys. Number one receiver Darrell Jackson is expected to return from a toe injury that has kept him out of the last four games. One of Chicago's defensive weaknesses is that they rank just 21st in DVOA against number one receivers. Their tendency towards zone coverage usually lets an opposing quarterback find his favorite target if he manages to stay upright. Of course, it's hard to identify a number one receiver in Seattle right now. Is it a still-hobbled Jackson, last week's star Engram, or former Super Bowl MVP Deion Branch?

So Hasselbeck will likely spread his passes around, to everyone except tight end Jerramy Stevens. He scored two touchdowns against Dallas, but Chicago has the best defense in the league against tight ends.

SPECIAL TEAMS

With rookie return man Devin Hester and kicker Robbie Gould leading the way, Chicago put up the second-highest special teams rating [17] in the ten years for which Football Outsiders has play-by-play breakdown. Hester set an NFL record with six return touchdowns, ranking second in punt return average and fifth in kickoff return average. Gould was excellent on both field goals and kickoffs. The Seahawks also had good special teams, ranking seventh overall. Kicker Josh Brown won four games for the Seahawks with field goals in the final minute of regulation, while rookie Ryan Plackemeier solved the punting problem that helped cost the Seahawks last year's Super Bowl. All those injuries in the secondary, however, also mean a host of new faces on the Seattle punt and kickoff coverage units.

OUTLOOK

Even with their defense faltering, Chicago is the heavy favorite in this game. Seattle's offense has been subpar all year, and the secondary is put together with scotch tape. But what if Hasselbeck and Alexander can, in fact, find their Super Bowl form of 2005? And what if Grossman has problems from his very first snap of the game?

Even though he gave Griese paying time in Chicago's last two games, Smith insists that Grossman is not on any sort of "short leash," and under no circumstances will he consider pulling his starting quarterback. But if Grossman throws an interception or two early on, can Smith possibly stick to that statement, knowing it might cost the Bears their best chance at a Super Bowl title in 20 years?

Stats Explained

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 [18]. 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 [19]). This is the same formula used in this week's FOXSports.com power rankings, and it includes wild card games. All numbers except for WEIGHTED DVOA are regular season only.

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.