The football season is halfway over, and division races are taking shape. Playoff spots have yet to be determined, but Jacksonville and Philadelphia have critical intradivisional games. The Jaguars travel to Tennessee to face the NFL’s best defense and the last-place Eagles host a Redskins team that leads Philadelphia by two games in the NFC East.

JAGUARS (5–3) at TITANS (6–2)
Sunday, 1 p.m.

Four years after being taken with the seventh-overall pick — and after racking up myriad injuries — the Jaguars released Byron Leftwich and installed his backup, David Garrard, as the team’s starter. Garrard led the team to a 4–2 record before injuring his ankle against the Colts on October 22. In his six starts, he completed 66% of his passes, threw six touchdowns, and didn’t have an interception.

The problem for the Jaguars, who play in arguably the most competitive division in the league, is that Garrard is likely to miss at least one more start. His replacement, Quinn Gray, has been an inconsistent passer.

In last week’s 41–24 loss to the Saints, Gray threw for 354 yards and two touchdowns. But he also tossed three interceptions, none more costly than the pick-six to New Orleans cornerback Mike McKenzie, during the first series of the second half.

Jacksonville’s defense, which ranked fourth in the NFL in fewest rushing yards allowed per game last season (91.2), has been the team’s glaring weakness in 2007. Midway through the season, the Jaguars have given up 107.8 rushing yards per game. With defensive tackle Marcus Stroud serving a four-game suspension for violating the league’s steroids and substance abuse policy, it could get worse.

The passing skills of the 2006 rookie of the year, Vince Young, have deteriorated in his sophomore season, which means the Titans have very little offense. But, the Titans’ defense has been dominant: It leads the league in points allowed (15.5), rushing yards allowed (66.0), and is second in total yards allowed (270.8) and interceptions (13). Albert Haynesworth and Kyle Vanden Bosch anchor the defensive line (each has five sacks), linebacker David Thornton leads the team in tackles (57), and linebacker Keith Bulluck has a team-high four interceptions.

Tennessee’s defense has no real weakness, playing the pass and run equally well. Jaguars’ running backs Maurice Jones-Drew and Fred Taylor won’t have much room to maneuver, meaning Gray will be forced to the air. He will have to be flawless to overcome a tenacious pass rush and a ball-hawking secondary.

REDSKINS (5–3) at EAGLES (3–5)
Sunday, 1 p.m.

After a 52–7 drubbing at the hands of the New England Patriots two weeks ago, the Redskins looked out of sorts for most of last week’s game against the 1–7 Jets. Washington won in overtime, but only mustered just one touchdown in 67 minutes against one of the NFL’s worst defenses. Quarterback Jason Campbell, in his first full year as the Redskins’ starter, is 10th in the league in pass completions of more than 40 yards (4), but he has yet to throw a touchdown pass to a wide receiver.

Nine weeks into the season, running back Clinton Portis was still looking for his first 100-yard rushing game. He finally got it against the Jets, finishing with 196 yards on 36 carries. Normally, such a performance would portend good things to come, but two factors suggest otherwise: Washington’s offensive line is still in flux following a flurry of early-season injuries, and Philadelphia’s defense is among the NFC’s best against the run.

Although only halfway through the schedule, there are plenty of reasons to think the Eagles are playing for draft position. Head coach Andy Reid has been under fire for off-field issues. The press and fans are calling for rookie second-rounder, Kevin Kolb, to replace Donovan McNabb at quarterback. And the club is 0–3 in the division — including a humbling effort against the Cowboys last Sunday.

The Eagles have been more unlucky than bad this season. If not for two muffed punts in the Week 1 loss to the Packers, or the fumbled snap-that-wasn’t against the Bears in Week 7, Philadelphia could be 5–3.

The Eagles’ run defense has been stout, allowing just 92.9 yards per game (third in the NFC). The Redskins are most successful running to the left, averaging more than 4.5 yards per carry, but Philadelphia has given up less than 3.5 yards in that direction.

The Eagles’ season hinges on this game. Lose and they are all but eliminated from the postseason; win and they are alive for another week. The Redskins are two games back of the division-leading Cowboys, and can’t afford to lose more ground. A loss would be devastating, but Washington would still be in the NFC playoff mix.

Mr. Wilson is a writer for FootballOutsiders.com.