Houston and Cleveland combined to win 10 games last season. A year later, both teams have improved, and the Browns are jockeying for a playoff spot. Only one game separates San Diego and Baltimore in the standings, but the Chargers are playing for first place in the AFC West while the Ravens are trying to remain within three games of the AFC North lead.

TEXANS (5–5) at BROWNS (6–4)
Sunday, 1 p.m.

The Texans are three games behind the Colts in the AFC South, one of the NFL’s most competitive divisions, but are coming off an impressive win over the Saints last week. Houston’s offensive improvement has much to do with new quarterback Matt Schaub, who has completed 67.1% of his throws with an efficiency his predecessor David Carr never possessed.

Last year, Houston was 28th in points per game (16.8). This season it ranks eighth (22.6). The Texans have yet to establish a ground game — Ron Dayne leads the team in rushing, with 437 yards on 121 carries (3.7 yards a carry) — but wide receiver Kevin Walter and tight end Owen Daniels have emerged as pass-catching threats. With Pro Bowler Andre Johnson back at full health, Houston should challenge Cleveland’s suspect secondary.

Part of the offense’s success is due to quarterback Derek Anderson’s ability to quickly get the ball to his playmakers, which is facilitated by his strong arm. He has tossed 20 touchdowns (4th in the league), and only 10 interceptions. Former first-round pick Braylon Edwards is playing like a legitimate no. 1 receiver and deep threat, and Kellen Winslow, who leads all tight ends in receiving yards, creates match-up problems for linebackers and safeties. The Browns’ offensive line has done an outstanding job of protecting Anderson, allowing the ninth fewest sacks of any team in the NFL.

Cleveland has an outside shot to win the division, but even if Pittsburgh takes the AFC North, the Browns are in prime position for a wild card berth.

RAVENS (4–6) at CHARGERS (5–5)
Sunday, 4:15 p.m.

The Ravens have dropped four straight games, and the toughest part of the schedule starts Sunday in San Diego. After the Chargers, Baltimore hosts Indianapolis and New England, before ending the season against Seattle and Pittsburgh. After winning 13 games last year, the Ravens were the popular choice to win the division.

As has been the case throughout head coach Brian Billick’s nine-year career, Baltimore has struggled to score, averaging just 16.8 points a game. Steve McNair has been both ineffective and injured, and a young offensive line has suffered through growing pains at McNair’s expense. A sore shoulder has McNair on the shelf indefinitely, and as the Ravens make a push for .500, it will come with Kyle Boller under center, facing one of the NFL’s most difficult schedules.

Baltimore’s defense remains one of the league’s best, however, ranking second in first downs allowed, fifth in third-down percentage, and sixth in total yardage per game.

The Chargers are also a team in transition; Norv Turner, a gifted offensive coordinator who owns a career 63–87–1 record as an NFL head coach, is in his first year in San Diego. A 14-win team a season ago under Marty Schottenheimer, Turner hasn’t had similar success with many of the same faces.

Second-year starting quarterback Philip Rivers has been inconsistent. After throwing 22 touchdowns and nine interceptions in 2006, Rivers has already tossed 12 picks, against 11 scores.

San Diego’s defense has also regressed. A year ago, the unit led the league in sacks, and was seventh in rushing yardage allowed; this season the Chargers rank 20th and 23rd, respectively.

Sunday, the Chargers could try to establish the running game early, control the clock, and give Rivers high-percentage, low-risk opportunities. It’s a conservative game plan, necessitated by a smothering defense and an inept offense.

Mr. Wilson is a writer for FootballOutsiders.com.