by Aaron Schatz

Looking solely at the season-long Football Outsiders stats, the New England Patriots have to be considered the favorites in this game. They get to play at home, and they rated higher than the Ravens over the course of the year. Look at our weighted ratings that give more strength to recent games, and the gap between the two teams becomes wider.

The argument against these overall ratings is to point at Baltimore's inconsistency this season. On the surface, it certainly looked like the Ravens played badly against the bad teams on their schedule but played well against their tougher opponents. The Ravens lost to Jacksonville and Seattle, but beat over-.500 teams six times, and then again last week in the playoffs. So now we have to ask ourself:

1) Is this true? Did Baltimore really "play down" or "play up" to the level of its competition?

2) Does this really matter for predicting who will win this game, or is it better to just look at overall performance in all games this season -- adjusted for opponent, of course, but including all opponents?

Let's start with the first question. The answer is "somewhat." The Ravens lost four games this year, but they were not all to bad teams. Yes, they lost to Jacksonville and Seattle, but they also lost to an average team (San Diego) and an above-average team (Tennessee). They escaped with a narrow victory in their second game against Cleveland, but they easily won their first game against Cleveland, and they sure didn't play down to the level of the St. Louis Rams. They stomped them 37-7.

Let's see if we can measure the concept of "playing to the level of competition" with more than just anecdotal evidence. I took each team in 2011 and found the correlation of single-game DVOA to the season DVOA of the opponent in that game. A team that plays its best games against teams with positive DVOA and its worst games against teams with negative DVOA will have a positive correlation. A team that plays its best games against its worst opponents will have negative correlation.

Baltimore's correlation for 2011 is .27. That's fifth in the NFL, so it does indicate that the Ravens tended to play to the level of their opponents. But you may be surprised which two teams are one-two in correlation for 2011: Green Bay and New Orleans. Did this help them in the playoffs? Apparently not. The Giants, 49ers, and Patriots are all very close to zero using this measure. The teams with the strongest negative correlation between performance and the quality of the opposition were the Jets, the Dolphins, and the Falcons.

One year ago, in 2010, Baltimore had the second-largest negative correlation between opponent quality and single-game performance, at -.38, with the same head coach and virtually all the same players. If there's something real to the idea that Baltimore plays down to the level of its worst opponents, it hasn't been real for more than one season.

Looking back at this metric for the last five years, does there seem to be any connection to how well teams play in the postseason? Not really. One of the strongest correlations in 2010 belonged to AFC Champion Pittsburgh, but the 2010 Packers are at zero. The Super Bowl teams in 2009 and 2007 are all between .20 and .30, which would seem to indicate that a positive correlation is good. However, in 2008, the two strongest negative correlations belonged to the two teams that met in the Super Bowl: Pittsburgh at -.50 and Arizona at -.51. The second-strongest positive correlation that same year belongs to the 12-4 Indianapolis team that was upset in the wild card round by an 8-8 San Diego team that had a slightly higher DVOA.

Meanwhile, that whole thing about the Patriots not beating an over-.500 team all season? You could also say that about the 1999 Rams. They won the Super Bowl anyway. It's important to adjust for opponent when you judge a team's performance, but evidence suggests that you don't get a better idea of a team's playoff future by only looking at how they did against the best teams on their schedule. You need to look at the whole picture. That's what we'll do below.

For those who may be unfamiliar with the Football Outsiders stats, they are explained at the bottom of the page. Scroll down or click this link. Please remember that all stats represent regular season only, except for weighted DVOA and anything else specifically noted. Game charting data is still incomplete, but represents most of the regular season.

Baltimore at New England



Ravens on Offense BAL OFF NE DEF DVOA 8.2% (13) 17.9% (30) WEI DVOA 8.3% (13) 15.5% (26) PASS 20.3% (14) 24.1% (28) RUSH 8.1% (9) 8.8% (28) RED ZONE 5.1% (8) -15.9% (8) Patriots on Offense NE OFF BAL DEF DVOA 36.8% (3) -13.7% (1) WEI DVOA 40.1% (2) -9.6% (3) PASS 60.7% (2) -16.4% (1) RUSH 17.1% (4) -10.5% (7) RED ZONE 33.0% (3) -43.6% (3) Special Teams BAL NE DVOA -4.7% (30) 3.7% (5) BAL kickoff -7.4 (28) -3.7 (25) NE kickoff -5.9 (29) 8.7 (3) BAL punts -7.7 (27) -0.2 (18) NE punts -1.6 (19) 15.2 (2) FG/XP -5.0 (23) 1.5 (14)

All readers can click here for in-game discussion on our message boards. If you have FO Premium, you can click here to see all the matchup of DVOA splits for this game.

WHEN THE RAVENS HAVE THE BALL

In this era of multiple receivers and shotgun spreads, the Ravens actually run a fairly conventional, old-fashioned offense. Our charting lists the Ravens using two wide receivers on 56 percent of plays, the highest rate in the league. They run more often than they pass on first down. They like their play-action passes, although they used play action less this year than in past years. We've got them down with play fakes on just 15.2 percent of passes, which is actually below average.

We all know that passing is usually a more efficient way to gain yardage than running, but Ray Rice is a very good running back and there's a real opening for the Ravens to gain yardage on the ground in this game. The Ravens running game has improved significantly over the last couple months of the season, ranking 22nd in rushing DVOA for Weeks 1-9, then third in rushing DVOA for Weeks 10-17. Ray Rice went from 4.0 yards per carry and a 40 percent Success Rate in the first eight games to 5.27 yards per carry and a 49 percent Success Rate in the final eight. Meanwhile, the Patriots run defense was bad and got worse in the second half of the season, ranking 22nd in run defense DVOA for Weeks 1-9 but 28th for Weeks 10-17.

Looking at Adjusted Line Yards, there's a real opening for the Ravens to run Rice outside to the left, as they rank first in ALY on runs left end while the Patriots defense is 31st.

Fear of Ray Rice is supposed to open things up for the Ravens' play-action passing game, but here's where we get to the dirty little secret: The Ravens are not a good play-action passing team, and it has been this way for years. Most teams gain more yards per play when they use a play-action fake. The Ravens don't. In on our game charting so far, the Ravens average 5.3 yards per play with play-action, compared to 6.2 yards per play otherwise. This gap of .84 yards is the third-worst in the league for 2011. (Interestingly, two other run-focused offenses are worse: Jacksonville and Oakland.) Although the differences in yardage changed each year, the Ravens had a better DVOA without play action than they did with play action in 2008, 2009, and 2010.

The Pats were 26th giving up yardage with play action (8.2 yards per play) and 29th giving up yardage without play action (7.2 yards per play). This discussion of a Patriots defensive split, like a lot of discussion of Patriots defensive splits this year, ends up sounding a bit like Green Eggs and Ham. The Patriots defense sucked against play action, and it sucked without play action. It sucked on first down, and it sucked on third down. It sucked in the first quarter, and it sucked in the fourth quarter. It sucked on a boat, and it sucked with a goat.

Nevertheless, we can find some hints as to where the Patriots' worst defensive weaknesses are, and a few places where they were actually pretty good. For example, we know the Ravens like to use Ray Rice in the passing game, but the Patriots were very good against running backs in the passing game, ranking fourth in DVOA. That success is part of the reason why New England was actually pretty close to average on shorter passes, 15 yards or less through the air. Using the "defense vs. receivers" DVOA*, the Patriots come out with a -3.0% DVOA against these short passes. They allow an average of 6.47 yards per pass, slightly above the league average of 6.22 yards per pass.

However, the Patriots were the worst team in the league against deep passes. They had the worst DVOA against passes that went 16 or more yards through the air. They allowed 14.6 yards per pass on these throws, compared to an NFL average of 12.2. The longer the pass, the worse the Patriots were compared to the rest of the NFL. During the regular season, the Patriots gave up 21 completions or defensive pass interference calls on long bombs that went over 25 yards through the air. No other team gave up more than 16.

Were the Ravens a good deep passing team? Not particularly. Theoretically, these deep throws are the best part of Joe Flacco's game. He's got an arm like a howitzer. Unfortunately, Anquan Boldin can't get separation from cornerbacks, Torrey Smith is young and experienced, and Lee Evans couldn't stay healthy. The Ravens averaged 10.5 yards per pass on deep throws. Ravens receivers only caught 30 percent of deep throws, the lowest figure in the league. There's an interesting split here. The Ravens were pretty lousy at "deep but not too deep" throws, i.e. 16-25 yards through the air. However, they did really well with long bombs, and had 18 successful plays on those bombs. Most of those passes were to Torrey Smith, and the Ravens particularly took advantage when the defensive backs made contact. Joe Flacco threw six different passes to Smith that went 50 yards or more through the air; three were incomplete, and three led to huge DPI penalties.

Evans had a nice deep catch on the sideline last week against Houston, but that was one of only eight snaps he played all game. If the Ravens are going to take advantage of the Patriots' susceptibility to deep passes, they're going to do it with Torrey Smith. And who will likely be covering Smith deep? That's an interesting question. A lot of those successful bombs against the Patriots this year involved beating left cornerback Devin McCourty, who had an awful sophomore slump. However, in the last two games, the Patriots have mostly used a defense that switched McCourty to free safety and instead used safety Sterling Moore as the left cornerback. We don't have enough charting data on Moore to give any worthwhile stats on his coverage skills, and while McCourty-as-safety seems to be a huge success, most of that success came with Tim Tebow as the opposing quarterback. So McCourty will probably be near those bombs to Smith, but this time as the deep safety help, and we don't really know if that makes the Patriots a better defense against the bomb than they were during the season.

Of course, if Joe Flacco wants to launch it downfield, he needs to stay upright long enough to do it. We know that Flacco likes to hold onto the ball sometimes a little too long, although our own J.J. Cooper reports that this tendency wasn't quite as bad in 2011 as it was in 2010. Can the Patriots get to Flacco while he's trying to figure out where to throw it? Many people thought the Patriots pass rush was in trouble when defensive Andre Carter went down with an injury during the Week 13 game against Denver. But the Patriots' Adjusted Sack Rate has actually improved since then. Including last week's playoff game, the Patriots have gone from 5.9 percent ASR through Week 13 to 9.9 percent ASR in Weeks 14-19.

Speaking of trends, there are some interesting first half/second half trends when it comes to the Ravens receivers. In the second half of the season, Flacco threw to his tight ends less often but had more success when he did. Ed Dickson and Dennis Pitta went from 10.6 targets per game in Weeks 1-9 to 7.5 targets per game in Weeks 10-17. However, together their catch rate improved from 60 percent to 72 percent, and their DVOA improved from -1.9% to 29.1%. The other split to note is that since midseason, the Ravens have ended up using Ray Rice more as a safety valve for dumpoffs than on planned passing routes. His catch rate has gone from 68 percent before Week 10 to 79 percent since Week 10, but his receiving DVOA has dropped from 51.0% to 6.2% and yards per reception have dropped frmo 10.9 to 7.6.

* Are you wondering what makes "defense vs. receivers" DVOA different from regular team DVOA? Well, regular team DVOA -- which is also the numbers we're giving when we usually talk about a team's passing game or running game -- uses a baseline of all offensive plays including some penalties. However, "defense vs. receivers" DVOA is based on the same set of plays as a receiver's DVOA, so it only includes passes with an intended receiver. Defense vs. receivers, unlike the DVOA for receivers on offense, includes a bonus for defenses who get interceptions.

WHEN THE PATRIOTS HAVE THE BALL

According to our DVOA ratings, the Ravens had the best defense in the NFL this season. The Patriots had the third best offense in the league this season. However, 1-32 rankings aren't necessarily the best way to compare units. When we say the Ravens had the best defense in the league, what we mean is "the Ravens defense was pretty good, and slightly better than the other pretty good defenses of 2011." When we say the Patriots had the third best offense in the league, what we mean is "the New England Patriots offense was historically powerful with a passing game light years ahead of every other offense in the league except for New Orleans and Green Bay, two offenses which were also historically powerful."

As you may notice on the chart to our left, the Patriots did not have a single game with an offensive DVOA under 0% all season. They haven't had a game with offensive DVOA below 30% since Week 11. The Ravens, on the other hand, had six games with a defensive DVOA above 0%, and three of those games were the final three games of the regular season.

If you are a believer that teams develop over the course of the season, you've got to be a little extra worried about the Ravens in this game. The Ravens defense has simply not been the same since beginning of November. During the first nine weeks of the season, the Ravens defense ranked second against the pass, second against the run, and first overall. Since Week 10 (including the playoffs), the Ravens defense ranks fourth against the pass, 15th against the run, and seventh overall. Those ranks would be even worse if we didn't include last week's playoff game, as the Ravens did right the ship a bit against the Houston Texans.

(The Patriots, by the way, have the exact same ranks in each half of the season: second passing, fourth rushing, and second overall. The only difference is that in the first half of the year, as you can see on the chart, their offense generally had higher highs and lower lows.)

The biggest strength of the Ravens defense this season has been the pass rush, and it's stayed strong over the last few weeks even as the rest of the defense faded a bit. It's a surprise because the pass rush was the Ravens' clearest defensive weakness going into this season. Last year, the Ravens were 27th in Adjusted Sack Rate at 5.5 percent. This year, they were second at 8.4 percent, and that's gone from 8.1 percent through Week 9 to 8.7 percent since Week 10. Terrell Suggs is the top pass rusher on the team, just as he has been for years. (He had 11 sacks in 2010, 14 sacks this year.) The big improvement has come from a couple of situational pass rushers: fifth-round rookie Pernell McPhee (6.0 sacks) and third-year veteran Paul Kruger (5.5 sacks), who played very little in his first two seasons. There are also more sacks coming out of more complex blitzes; the Ravens had just one sack from a defensive back in 2010, but six in 2011.

McPhee and Kruger primarily play in third-down sub packages, which is a big reason why the Ravens have the league's best Adjusted Sack Rate on third downs at 11.6 percent. Tom Brady is sacked almost twice as often on third downs, with a 4.4 percent ASR on first and second down but 8.7 percent ASR on third and fourth down, so we can expect a couple of drives to end when Brady is caught in the pocket with nowhere to go on third down. It will be interesting to see if the Ravens want to try to bring more consistent pressure on Brady by using those sub packages on first and second down too, giving McPhee and Kruger more time on the field -- especially considering the way the Patriots like to use the no huddle to keep their opponents from substituting in extra defensive backs and situational pass rushers. Tom Brady excels against big blitzes, so the Ravens want to limit those and bring just four or five pass rushers. Based on our current numbers, Brady was actually a little worse against five (7.4 yards per play) than he was against four (8.1 yards per play) and the Ravens bring five on 29 percent of passes (fifth in the NFL).

One reason the Patriots can go no huddle so often, of course, is the flexability of their two tight ends. In this week's Quick Reads, Vince Verhei covered the question of how the Ravens might possibly hope to cover both Rob Gronkowski and Aaron Hernandez. Vince pointed out that the Dallas Cowboys did the best job of covering the Patriots tight ends back in Week 6, keeping them below 10 yards on 10 of their 15 receptions. Quick Reads goes into more detail on the specifics, but in general the Cowboys used a variety of zone coverages to avoid big plays, cut down on mismatches, and rely on their pass rush to force Tom Brady into errant throws. Sometimes we listed a linebacker on Gronkowski or Hernandez, sometimes a cornerback.

There's been so much talk about the Ravens' blowout of the Patriots in the 2009 playoffs that most commentators have completely ignored that these teams also played each other just last year. That game was also in New England, and the Patriots won 23-20 in overtime. Gronkowski and Hernandez didn't play quite as big a role in the Patriots offense then as they do now, but they were important. Hernandez had four receptions for 61 yards. (Some may think the idea of Aaron Hernandez in the backfield is a new one, but Hernandez caught a 30-yard pass out of the fullback position in an offset I in that game.) Gronkowski was only thrown two passes, but one was a 24-yard catch and the other was a 13-yard pass interference on Lardarius Webb. Both tight ends were open every time Brady threw to them, and only had incompletes because Hernandez dropped two passes in overtime. Unfortunately, it's hard to tell from last year's game who might cover the tight ends this week, because half the time we have coverage listed as "hole in zone" and no defender is listed in coverage more than once.

The Ravens' most common defender this year against tight ends was either strong safety Bernard Pollard or inside linebacker Jameel McClain. One of them was listed as the primary defender on 25 percent of passes to tight ends this year. (That may not sound like a high number, but remember that a lot of passes to tight ends will be marked "Hole in Zone.") In general, these defenders did well against tight ends, as the Ravens ranked third in DVOA against tight ends and allowed just 30.8 opponent-adjusted yards per game. The Ravens kept Antonio Gates to just two catches for 31 yards and kept Vernon Davis to four catches for 38 yards. That's probably good news for keeping the Gronk from another superhuman day, but does it really tell us much about how the Ravens could handle Hernandez, who is mostly split wide or coming out of the backfield?

The Ravens cornerbacks had similar charting numbers: left cornerback Lardarius Webb was at 6.9 yards per pass with a 57 percent success rate, while right cornerback Cary Williams allowed 7.0 yards per pass with a 52 percent success rate. The big statistical difference between the two was interceptions, as Webb had five and Williams zero. Webb did an excellent job all year playing wide receivers on short passes. The Ravens had the best DVOA in the league against passes to the "short right" area, allowing a league-low 4.3 yards per pass (the NFL average on short right passes was 5.7 yards). Nine of Baltimore's 15 picks came on the offensive right side of the field. However, Brady's passes to wide receivers tend to be on the left side or in the middle of the field, while his passes to tight ends tend to be on the right side or in the middle of the field. Wes Welker and Deion Branch combined for just 61 targets on the right, as opposed to 66 in the middle and 99 on the left. If the Ravens want to leave Webb at the left cornerback position, he's not going to spend much time covering Welker or Branch. The 5-foot-10 Webb will be giving up four inches and 70 pounds if he tries to cover a split-out Hernandez, and I don't even want to imagine the carnage if he has to cover a split-out Gronkowski.

Since the Patriots so often spread the field and go with an empty backfield, there's a general impression that they don't have a good ground attack. That would be incorrect. When they want to run, the Patriots are very efficient, in large part because they often have the defense on their heels expecting pass. The Patriots get steady gains, not long runs. They were second in Adjusted Line Yards, but 30th in Open Field Yards per carry. The Ravens had good run defense, but they weren't quite as stalwart when opponents were running out of the shotgun. They allowed 5.79 yards per carry to opposing running backs on runs out of shotgun, which ranked 21st in the NFL. That could be a problem against the Patriots.

The Patriots also do run enough to set up play action, and they really excel on these plays. The Patriots gained 3.5 more yards per pass attempt when using play action, the third-highest difference between play action and non-play action in the NFL. The Ravens defense was somewhat susceptible to play action, allowing 1.7 more yards per play when opponents used a play fake (tied for the ninth biggest difference in the NFL).

SPECIAL TEAMS

Now, here's a big difference between these two teams. The Patriots were one of the top teams in our special teams ratings this year. The Ravens, after a great year on special teams in 2010, plummeted all the way down to 30th. Part of the problem was a calf injury that hurt Bill Cundiff's accuracy on field goals. He was also down in kickoff value this season, although he still led the league with 5.6 estimated points worth of field position on gross kickoff value. However, the Baltimore coverage teams were lousy. The Ravens allowed 9.9 points worth of value on kick returns (second to Oakland) and 9.3 points worth of value on punt returns (third behind Carolina and Arizona).

The Patriots, on the other hand, were fantastic on kickoff distance, punt distance, and coverage on both, which helped them to shift field position even though their defense was giving up lots of yards. The special teams disparity didn't translate into a big difference between these teams in starting position on offense, but it mattered for starting position on defense. On average, the Ravens defense needed to defend 71 yards of the field every time the opposing offense started a new drive. By comparison, the Patriots defense got to defend an average of 76 yards of field.

Reader @FoxForceFlacco pointed out to me on Twitter that the Ravens overhauled their coverage teams for last week's playoff game, using more starters, so it is possible this may not be as big a mismatch as it seems, but it's hard to definitively make that statement after just one game of improved special teams against Houston.

OUTLOOK

This game is far from a slam dunk for the Patriots, but a lot of the matchups point their way. It's not hard for offenses to gain passing yards on the Patriots defense, but the Ravens' passing game just doesn't seem to be particularly suited to picking on the Patriots' greatest weaknesses unless Joe Flacco can hit a couple of deep bombs to Torrey Smith. Ray Rice should have a big day on the ground, but it is hard to outscore Tom Brady and this Patriots offense primarily with your running game. The Ravens can try to limit the Patriots offense somewhat, and the pass rush will get to Brady, but it's hard to imagine that the Ravens can cover everybody the Patriots can send out on pass patterns. Some of this year's numbers suggest that the Ravens could do better than expected against the Boston TE Party, but last year's Ravens-Patriots game suggests the opposite. Even if the Ravens can limit Gronkowksi and Hernandez, they still need to cover both Welker and Branch, and the Patriots' likely field-position advantage from special teams just makes it easier for Brady to reach the end zone with his steady diet of 10-to-15 yard passes. New England is the clear favorite to advance to Super Bowl XLVI.



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. 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.

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. Those numbers are explained here.

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.) We also list red zone DVOA and WEIGHTED DVOA (WEI 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).

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 rolling average of the last five games. There are separate charts for offense and defense for each team.