By Jason B. Hirschhorn

With only seven weeks left in the 2014 regular season, teams have begun to reveal their true identities. Some, like the San Diego Chargers, have shown that their hot starts were unsustainable while others, such as the New England Patriots, have recovered nicely after stumbling out of the gate. While the balance of power in the league can still be shifted by injury or suspension, we can now look around and identify the realistic title contenders.

New England Patriots

Why they'll win: After a slow opening quarter of the season in which the New England Patriots eclipsed 21 points just once, the offense has reclaimed their championship form. In their last five games -- all wins -- the Patriots have scored no fewer than 27 points while the team as a whole has moved into third in points per game with 31.2. Only the Denver Broncos (who they beat in October) and the Indianapolis Colts (New England's next opponent) have performed better.

The lion's share of the credit will always go to Tom Brady, but the true difference maker for the Patriots this year has been tight end Rob Gronkowski. Early in the year when he was still recovering from ACL and MCL tears in his right knee suffered last December, Gronkowski plodded around struggled to create separation, thus reducing him to mostly a red zone target. Through the first four games, he averaged just over three catches and 36 yards. As a direct result, opposing defenses held Brady and the offense to under 250 passing yards every game during that stretch. Pundits questioned whether the Patriots' run of dominance had ended, with local media members asking if a quarterback change was in the works.

The narrative changed in early October. Gronkowski, now 10 months removed from his knee injury, began to resemble the defense-shattering field tilter of old. Running smoother and ditching defenders with ease, Gronkowski is averaging more than 100 yards over the Patriots' last five games, doubling his touchdown total in the process. Meanwhile, Brady's production has spiked, exceeding 250 yards passing every week. This version of New England's offense looks as indefensible as any in the league.

Why they won't: One of the biggest preseason questions regarding the Patriots was whether their aging defense could hold up against the run. Through nine games, it seems safe to say opposing rushers won't have to worry. Heading into their bye, New England yielded an average of 120 yards on the ground at a clip of 4.4 per carry. Football Outsiders ranked them 26th in rush defense DVOA. Those figures project to drop even more as linebacker Jerod Mayo was lost for the season just a few weeks ago and defensive end Chandler Jones remains sidelined with a hip injury.

New England's inability to stop the run could be a serious problem down the stretch and into the postseason. November opponents Green Bay and Miami both possess power run games that could exploit the Patriots' porous defense. The same can be said for Denver, which has discovered a potent one-two punch in Ronnie Hillman and C.J. Anderson. Even the Colts who have struggled to run the ball effectively with Trent Richardson are beginning to turn more and more to Ahmad Bradshaw. The Patriots offense will have to continue their torrid pace to make up for the damage these teams could cause.

Denver Broncos

Why they'll win: In large part because of injuries to Von Miller and Rahim Moore, the 2013 Denver Broncos succeeded in spite of their defense rather than because of it. Sensing that the championship window for his team is closing, executive VP of football operations and general manager John Elway made a bevy of moves to fortify the defense, including acquiring All-Pros DeMarcus Ware and Aqib Talib as well as Pro Bowl safety T.J. Ward. As a result, a Broncos defense that gave up the 22nd most points per game last season has improved to fifth in 2014. Likewise, their defensive DVOA has improved from 15th in 2013 to second this year.

Meanwhile, Peyton Manning is in the midst of another MVP-level season. Already, Manning has thrown 29 touchdowns with only seven interceptions all while completing nearly 68 percent of his passes. If his current rates hold Manning will throw for over 5,000 yards and 52 touchdowns. Though that's technically a step down from last year, the prospect of playing the Broncos remains terrifying for opposing defenses.

Why they won't: Knowshon Moreno departing in free agency was quietly one of the more significant losses for the title contender. Moreno wasn't flashy, but his 1,586 total yards from scrimmage were a significant contribution to Denver's offense. Moreno's initial replacement Montee Ball looked feeble before a groin injury sidelined him. Ronnie Hillman provided a greater impact but has physical limitations at 5-foot-10 195 pounds. The ground game becomes more important as the weather turns, and it remains to be seen whether any of the Broncos' backs can carry the load the way Moreno did.

Arizona Cardinals

Why they'll win: No one in today's NFL calls a more aggressive defense than Arizona Cardinals defensive coordinator Todd Bowles. Aggression isn't necessarily a positive, but it is when it provides the results Bowls is getting. The Cardinals are on pace to lead the league in unblocked pressure for the second consecutive year, and it almost hasn't mattered which players are on the field. The team has withstood prolonged absences for starters Calais Campbell and Matt Shaughnessy and has played without Darnell Dockett, Daryl Washington, and John Abraham for the entire season. Bowles has enticed decent play out of youngsters Sam Acho, Kevin Minter, and Ed Stinson while squeezing the last bit of juice from veteran Larry Foote. For his efforts, Bowles has constructed the league's sixth best defense by DVOA.

Though the offense won't be confused with an elite unit, it has performed well enough in the trenches to keep drives alive. When the team went 10-6 in 2013, they did so despite an offensive line that gave up 242 pressures, the second worst total in the league. This year, the addition of left tackle Jared Veldheer as well as improved play along the interior has reduced that total to 101 through 10 weeks.

Why they won't: Perhaps no injury will have a more significant impact on the 2014 season as Carson Palmer's ACL tear. Though Bowles' defense provided the driving force behind the team's 8-1 record, quality offensive play is needed to make Arizona's success sustainable. With Palmer at the controls, such production could be depended on. In his six starts, the Cardinals averaged 25.8 points. That figure would place them just outside the top 10 in scoring. And since Palmer returned from his shoulder injury, the team has averaged an even more robust 27.4 points.

Arizona's production in games started by Drew Stanton don't compare favorably. In those contests, the team averaged only 22.7 points per game. While that figure is close to the league average, it underscores the magnitude of difference between a reliable veteran like Palmer and a journeyman signal caller such as Stanton.

Detroit Lions

Why they'll win: The Detroit Lions have the best, most complete defense in the NFL. The unit leads in every notable metric. Their 15.8 points allowed per game is a full point better than the next closest team. Detroit is the only team to hold opponents to under 300 yards per game through 10 weeks. Those numbers are confirmed by DVOA, which rates the Lions as the No. 1 team against the run and No. 2 versus the pass. The success stems from new defensive coordinator Teryl Austin, who has conjured respectable play from a secondary without a single star player. Elsewhere, Ndamukong Suh and the defensive line remain the best such group in football.

Why they won't: For all the positives new head coach Jim Caldwell brings in terms of composure and attitude, his team's offensive performance has dipped badly. Even with the star power of Calvin Johnson, Matthew Stafford, and Reggie Bush, the offense struggles to move the ball and put points on the board. The team ranks 19th in yards gained per game and 24th in per game scoring, by far the worst among current division leaders. Matthew Stafford has regressed badly this season, tossing eight picks against just 13 touchdowns. The offensive line hasn't helped, yielding the 12th most pressures through 10 weeks. 

Philadelphia Eagles

Why they'll win: Chip Kelly's offense hasn't slipped in his second year in Philadelphia. The Eagles score more points per game (31.0) than any other team in the NFC. That's over three points better than their mark from a year ago. Part of the improvement can be traced to the acquisition of Darren Sproles. Kelly has utilized Sproles in a number of ways, and he has provided even greater gains through the air (257 yards) as on the ground (236). Kelly has also carved out a role for rookie receiver Jordan Matthews. The former Vanderbilt star has already become one of the team's best short and intermediate targets and is quietly on pace for over 800 yards and nine touchdowns. Most importantly, the offensive line is finally healthy which should provide a boost to the entire offense.

Why they won't: It does not appear as though LeSean McCoy, the Eagles most dynamic playmaker, will break out of his slump this season. McCoy led the NFL in rushing yards last year with 1,607, yet is on pace to gain over 450 fewer in 2014. A more significant worry is his yards per carry, which stands at a subpar 3.7. Without McCoy forcing defenses to drop a safety into the box, the Eagles' passing attack will be considerably easier to stop in the playoffs. That's assuming the unit doesn't take a step back with Mark Sanchez, who replaced the injured Nick Foles late in Week 9.

Green Bay Packers

Why they'll win: In the NFL, a great quarterback can lift a team to a championship, and no quarterback is playing better than Aaron Rodgers. His 25:3 touchdown-to-interception ratio is the best in the league, and every pick has come off a receiver's hands. Especially of late, Rodgers' ball placement has been exquisite, with receivers rarely having to adjust to a misfired pass. To further highlight Rodgers' dominance, he's on pace to nearly match or exceed several of the career marks set during his 2011 MVP campaign such as completion percentage (68.3), touchdown passes (45), passer rating (122.5), and fewest interceptions by a player with over 40 touchdowns (six).

And unlike in 2011, the Green Bay Packers have a defense capable of producing stops. Defensive coordinator Dom Capers has the unit playing its best football in years, especially against the pass. Opposing quarterbacks average under seven yards per pass attempt and have thrown just 13 scores, the sixth fewest in the league. Likewise, the Packers rank sixth in defensive passer rating (80.2). The advance metrics like their pass defense as well, with Football Outsiders ranking it 12th in DVOA.

Why they won't: Though the Packers' thrive when throwing the ball or defending the pass, opponents capable of running the ball effectively have enjoyed considerably more success. Against an inferior New Orleans team in Week 8, Green Bay yielded 193 rushing yards and a clip of 6.2. Similarly, Marshawn Lynch and the Seattle ground game produced 207 yards on just 37 carries. Even less heralded teams like the Dolphins managed well over 100 yards and nearly five yards a carry. The Packers have trotted out multiple defensive fronts and interchanged personnel, but run defense continues to be an issue for them.

And in spite of Green Bay's myriad offensive accolades, the team currently sits outside the playoff picture. Though that will likely change in the coming weeks, the fact that a 6-3 team with the second-highest scoring offense in the NFC is currently not one of the top six teams in the conference underscores how much power is concentrated at the top.

Dallas Cowboys

Why they'll win: Amazingly, the Dallas Cowboys could win because of the defensive improvement stewarded by coordinator Rod Marinelli. With lynchpin starters DeMarcus Ware and Jason Hatcher departing this offseason and linebacker Sean Lee suffering a season-ending knee injury, Marinelli was asked to produce a capable unit out of perhaps the least talented group of defenders in the league.

The results have been staggering. Dallas has yielded the ninth fewest points per game (21.2) and has become a turnover-generating machine. Through 10 weeks, only six teams have more takeaways than Marinelli's Cowboys. The improvement has been reflected by Football Outsiders, which has Dallas rising from 30th in DVOA last year to 19th in 2014.

Why they won't: The health of Tony Romo isn't as precarious as that of Carson Palmer, but it's every bit as big of a concern. This offseason, Romo underwent surgery to repair a herniated disc in his back, leading many to wonder whether his mobility and thus his playmaking ability would suffer. After a few games, the 12-year veteran began to display his vintage form, dodging would-be tackles by the likes of J.J. Watt.

Everything changed in Week 7. In an unfortunate break, Romo took a knee to the back from linebacker Keenan Robinson. After minutes of lying almost immobilized on the turf, Romo was helped off the field and sent to the locker room. Though he would later return to the game after receiving pain medication, Romo would miss the team's following outing against Arizona and wasn't a guarantee to play this past Sunday in London. Romo may appear healthy now, but that back could knock him out at any time.

Seattle Seahawks

Why they'll win: The Seattle Seahawks entered 2014 with virtually the same roster that demolished the Broncos in the Super Bowl last season. The defense, highlighted by the "Legion of Boom" remains a difficult draw for any offense. All-Pro safety Earl Thomas covers so much ground that it allows defensive coordinator Dan Quinn to call primarily single-high looks. As a result, opposing teams have Kam Chancellor to worry about on the ground and in the short-to-intermediate passing game. On the other side of the ball, Marshawn Lynch leads a rushing attack that ranks first in the NFL in yards (170.9 per game), yards per carry (5.5), and touchdowns (14).

Why they won't: Injuries have changed the complexion of this Seattle team. Uber-athletic middle linebacker Bobby Wagner has missed most of the season with a toe injury. Byron Maxwell, a starting corner during last season's title run, strained his calf in mid-October. He was held out until this past Sunday and only returned in a reserve role. Even the indestructible Chancellor was sidelined the past two weeks with a groin injury. The Seahawks must also now play without starting defensive tackle Brandon Mebane for the remainder of the season. Though they remain competitive, the defending champs no longer look untouchable.

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Jason B. Hirschhorn is a contributing writer for Sports on Earth and covers the NFL for SB Nation and the Green Bay Packers for Acme Packing Company. Follow him on Twitter at @jbhirschhorn.