We may not know a whole lot about how the NFL season will play out at this point, but it appears as if we're set for a very unusual, very competitive race to the postseason.
A dozen teams entered Week 4 with a 2-1 record (Baltimore moved to 3-1 on Thursday), and 16 more carried 1-2 marks into the weekend. When will the cream start rising to the top? Maybe soon. All three of the NFL's remaining undefeated teams (Atlanta, Arizona, Houston) have winnable games in Week 4, and at least a couple divisions feature important rivalry games this Sunday.
Here's your primer for this week's action:
• Jets begin life off of Revis Island
For all their offensive woes, the Jets are 2-1 following an OT win over the Dolphins. They face the grim reality, though, of finding a way to keep winning with defensive standout Darrelle Revis sidelined for the season by a knee injury.
The first test is a big one: San Francisco, off a loss in Minnesota, will put pressure on the Jets all over the field. That includes via the passing game, where San Francisco features Mario Manningham, Michael Crabtree, tight end Vernon Davis and (if he's not riding the bench) Randy Moss.
Revis' injury is as substantial as we'll see this year. With a Super Bowl contender coming in Sunday, the Jets don't have any time to feel sorry for themselves.
• Can Seattle, Minnesota win on the road?
The Seahawks and Vikings are two of the surprises of the (very) young season -- Seattle coming off its controversial win over Green Bay, while Minnesota's fresh from a huge upset of the 49ers.
Both teams are 2-0 at home ... and 0-1 on the road. They'll get a chance to change the latter number this week. Seattle heads into St. Louis on Sunday to take on its division rival in what stands as a key early-season matchup. Same goes for Minnesota-Detroit, a game that the Lions desperately need to keep pace in the NFC North.
Seattle and Minnesota both could be 3-1 by late Sunday, but winning on the road is a much bigger task than getting the job done at home.
• Undefeateds shoot for 4-0
The 1972 Dolphins may be able to pop open the bubbly earlier than usual this season. In a parity-filled NFL, just three teams remain undefeated after three weeks of play: Atlanta, Houston and Arizona.
All three are at home this week and all three welcome in 1-2 teams -- Atlanta gets Cam Newton and Carolina, Houston hosts Tennessee and the surprising Cardinals take on Miami. Can any of the trio push forward to 4-0? Even if the answer is yes, we're still a long way from 16-0 being threatened.
• Starting to sort out the AFC West
Peyton Manning was supposed to clear up the AFC West picture, as his arrival made the defending division champion Broncos the odds-on favorite in the division again. Instead, through three weeks, the situation is as muddled as ever.
San Diego sits atop the division at 2-1, but is coming off a miserable 27-3 home loss to Atlanta. Behind the Chargers, the Broncos, Chiefs and Raiders are all 1-2. San Diego's in Kansas City this week, while Oakland visits Denver. Even if this division is destined for another subpar year, Sunday's matchups ought to provide a little more clarity on where we're headed.
• Patriots try to reverse course
You'll forgive the fans in Foxborough if they're a little uneasy right now. New England, with Aaron Hernandez sidelined and Wes Welker often relegated to a role behind Julian Edelman, is 1-2 and looking up at both Buffalo and the Jets in the division. Worse yet, the Patriots have lost two straight, including a 31-30 heartbreaker in Baltimore last Sunday night.
It's too early in the season for must-win games, but Sunday's visit to Buffalo certainly qualifies as the first fork in the road for the Patriots. It's a major moment for the Bills, too -- win, and they're two games clear of New England and, quite possibly, all alone in first place.
• That other AFC North threat
No, not Pittsburgh ...
The Cincinnati Bengals are 2-1 thanks to back-to-back wins over Cleveland and Washington. On the docket this week: a visit to Jacksonville, a team that's fresh off a road win over the Colts.
Baltimore already pushed its record to 3-1 with a Thursday night win over the Browns, but the stage is set for Cincinnati to really put its foot down. After Sunday's winnable game against the Jaguars, Cincinnati plays four of its next five at home, with the lone road game being at 0-4 Cleveland.
• Something's gotta give in Tampa Bay
The Buccaneers have had a downright miserable time trying to put points on the board, ranking 26th in the league through three weeks at an average of 20 points per game. Washington, on the other hand, might be 3-0 if it could do anything defensively -- the Redskins are putting up more points than any other team in the league (33 per game), but they're allowing 33.7.
If Tampa Bay wants to wake its dormant offense, Sunday's meeting with the Redskins provides the perfect opportunity.
• Saints, Packers in trouble already
Anyone have New Orleans and Green Bay a combined 1-5 heading into Week 4? The Saints-Packers matchup at Lambeau looked like one of the early season's premier showdowns; now it's a battle between teams frantically searching for some positive momentum before it gets too late.
Last year, in the same venue, the Packers turned in a thrilling 42-34 win over New Orleans to open the season. That 76-point total is probably a good target, given the issues both teams have on defense.
We know one thing for sure: Aaron Rodgers and Green Bay will be steaming mad after losing in Seattle last Monday on that disputed Hail Mary.
• Who is the NFC East's team to beat?
No division in football changes so drastically on a weekly basis like the NFC East. As things stand right now, the Cowboys, Eagles and Giants are all jumbled together at 2-1, with the Redskins just a game back.
New York heads to Philadelphia on Sunday night for the East's second intra-division matchup of the season. Can Eli Manning solve Philadelphia's secondary? Can the Eagles keep Michael Vick protected against New York's aggressive front? The winner here gets an early leg up in the division race, especially if Dallas loses on Monday night ...
• Defenses front and center on Monday
... And that's where we close our Week 4 look-ahead.
The 2-1 Cowboys welcome the 2-1 Bears to Dallas to wrap the week's action, and it's possible that both Tony Romo and Jay Cutler will wind up running for their lives in this one. Chicago's never-ending issues on the offensive line have been well-documented, but it's actually the Bears who lead the league in sacks on defense with 14.
The outcome in this one may simply come down to which team can keep its quarterback standing more often.