With six weeks of NFL action in the books, divisional slots are taking shape, and teams who want to climb the ladder will find it a tough task. The Titans and Texans are looking up from the bottom half of the AFC South, while the Cowboys intend to show the Vikings why a balanced attack on both sides of the ball is what makes good teams elite.

TITANS (3–2) at TEXANS (3–3)
Sunday, 1 p.m.

The second half of the 2006 season opened a lot of eyes to the Titans, who lost their first five games, but won six of their last eight. Only one of those wins was by more than a touchdown, and nearly every one was highlight-fabulous. Quarterback Vince Young was named the Offensive Rookie of the Year, and all signs pointed to a bright future.

This year, Young is having trouble with accuracy; he’s thrown four interceptions in his last two games and everything seems to be sailing high. He’s also day-to-day with a strained right quadriceps and was replaced by veteran backup Kerry Collins in the second half of the Titans’ 13–10 loss to Tampa Bay last Sunday. Collins can make plays — he engineered the drive that tied the Buccaneers late in the game — but it’s the run game, and Young’s mobility, that makes this offense go. Tennessee has more rushing attempts than any team but the Patriots.

This year, the real story for Jeff Fisher’s team is its defense. Only the Pittsburgh Steelers have allowed fewer first downs than the Titans, and no team has allowed fewer rushing yards per game (63.8). The Titans have only eight sacks, but their front four put tremendous pressure on Tampa Bay quarterback Jeff Garcia last week. The Bucs still won because Garcia used his ability to scramble and convert short passes. The Titans must be aware of the short pass because their defense stops the run so well — and nobody loves the short pass more than the Houston Texans.

The challenge for the Texans will be not only to overcome a 37–17 pounding at the hands of the Jacksonville Jaguars last week, but to get past the problems behind the loss. After a strong start to the season, quarterback Matt Schaub hasn’t managed a touchdown pass in his last two games. The loss of top receiver Andre Johnson, out since Week 2 with a knee injury, hasn’t helped. Houston’s run game is tied with Kansas City’s for the worst yards-per-carry average in the NFL at 3.1.

If the offense can’t get a foothold, success will depend on the Houston defense. Despite a small recent resurgence, the Texans’ front seven was abysmal against the Jags, allowing 244 yards on the ground — the third-highest total in team history. Houston’s pass defense is also below average, and depending on the injury situation, the Texans might have to prepare equally for Young’s mobility and Collins’s potential to spread the field. Coach Gary Kubiak will need his entire bag of tricks to keep the Texans from becoming the only AFC South team with a losing record.

VIKINGS (2–3) at COWBOYS (5–1)
Sunday, 4:15 p.m.

These two teams believe in running backs-by-committee, though there are two stars in the making. The Vikings will go with Chester Taylor and Adrian Peterson, but Peterson is the name you’ve heard this season — the seventh overall draft pick is one of the most exciting rookies in recent memory.

Peterson currently leads the NFL in rushing with 607 yards, he’s averaging 6.3 yards a carry, and he’s coming off a 224-yard performance against the defending NFC Champion Chicago Bears. The Offensive Rookie of the Year award is practically a fait accompli, but a full-time starting position isn’t — Vikings coach Brad Childress insists that Peterson and Taylor will continue to alternate, though Peterson’s 96 carries outstrip Taylor’s 33.

In Dallas, a less heralded but equally effective player is impressing observers and opponents . Third-year back Marion Barber alternates carries with Julius Jones, but Barber’s is the name to know. After two seasons of limited carries, Barber is enjoying a breakout season. His carries (65) are fewer than Jones’s (69), but he has averaged two more yards per carry and has four touchdowns to Jones’s one.

Barber will find this game a tough go because the Vikings’ run defense is the NFL’s best. Led by tackles Pat and Kevin Williams, Minnesota leads the NFL in yards per carry allowed (2.7). They haven’t allowed a rushing touchdown all season. Dallas quarterback Tony Romo must exploit the Vikings’ pass defense, an escape hatch for offenses that need to move the ball. No team faced fewer rushing attempts and more passes in 2006, a trend that’s here to stay.

Romo could be Minnesota’s main problem. Mobile in the pocket and surprisingly heady for his short time as a starter, he knows how use his weapons. The Cowboys have three different receivers with four touchdown receptions — Terrell Owens, Patrick Crayton, and tight end Jason Witten, who’s this team’s real threat right now.

The Vikings have no such offensive symmetry. Quarterback Tarvaris Jackson has completed less than half his pass attempts this season, and he’s thrown three more interceptions than touchdowns. To be fair, the Vikings don’t have Dallas’ cadre of receivers, which makes Peterson’s accomplishments all the more impressive. After missing two games with a groin injury, Jackson completed nine of 23 passes against the Bears. To beat the NFC’s best team this week, Childress can’t be satisfied with stopping Dallas from airing it out — he’ll have to design a show of his own.

Mr. Farrar is a writer for FootballOutsiders.com.