Week 17 in the NFL exists in a strange netherworld between preseason and postseason. Each year, more and more playoff teams rest their starters and render the final, regularseason game meaningless. Other teams are still fighting for the last few postseason spots with one eye on the scoreboard, hoping for the special combination of wins and losses that makes them victorious in the NFL’s Rube Goldberg-designed tiebreaker system.

Many of the complicated AFC scenarios depend upon Jacksonville at Kansas City (1 p.m. ET, CBS). A Jacksonville victory will guarantee the Denver Broncos one of the two AFC wild cards before they start their game on Sunday, but it won’t do much for the Jaguars. To make the playoffs, the winner of this game also needs three other teams to lose: Tennessee, Cincinnati, and either the Jets (if Jacksonville wins) or the Broncos (if Kansas City wins).

Jacksonville is the better team by a significant margin, based on Football Outsiders’ Defense-adjusted Value Over Average ratings (DVOA) — which break down each play of the season and compare it to the NFL average based on situation and opponent. The Jaguars rank fourth if we give more weight to recent performance, while the Chiefs rank 15th. But the Jaguars are also the league’s most inconsistent team this season, and the Chiefs rank third in that category, so either of these teams could come out firing on all cylinders or flat as a pancake.

Kansas City’s offense revolves around running back Larry Johnson and tight end Tony Gonzalez. Jacksonville’s pass defense ranks third in DVOA, and the Jaguars are above average covering every type of receiver — except for tight ends. On the other hand, the one area where Jacksonville has remained consistent (win or lose) is run defense, particularly up the middle with defensive tackles Marcus Stroud and John Henderson. Only four opponents have managed more than four yards per carry against the Jaguars, although they gave up a season-high 4.4 yards per carry to New England last week.

Jacksonville’s offense is also run-oriented, and veteran Fred Taylor should be healthy and sharing time with Rookie of the Year candidate Maurice Jones-Drew. Kansas City’s run defense has faltered in recent weeks; it ranked 10th in DVOA through Week 8, but ranks 24th in Weeks 9–16. The Chiefs also have a very shallow secondary behind cornerback Patrick Surtain — Ty Law, in particular, has declined over the last two seasons — and that’s a problem against a team, like Jacksonville, that spreads the ball around with no favored receiver.

If the Chiefs upset the Jaguars, San Francisco at Denver (4:15 p.m., FOX), becomes a must-win for the Broncos. But that shouldn’t be much of a problem, especially in front of the home crowd. Like a lot of rookie quarterbacks, Jay Cutler can come unglued under heavy pass pressure, but the 49ers don’t have a particularly strong front four.

The 49ers defense is 29th in pass defense and 28th in run defense, so the Denver offense should have a good day all around. But the biggest star of the day should be tight end Tony Scheffler. Scheffler has been a bigger part of the offense since Cutler took over for veteran Jake Plummer, and San Francisco is the worst defense in the league against tight ends.

Pittsburgh at Cincinnati (1 p.m., CBS) only has bearing on the playoffs if the Jets or Broncos lose, but that doesn’t make it otherwise unimportant. Many “rivalries” in the NFL are really just rivalries between two groups of fans, but this rivalry exists between the players as well. The Bengals think they would have been Super Bowl champions, not the Steelers, if not for the injury Pittsburgh inflicted on quarterback Carson Palmer early in last year’s playoff game, and the two teams have spent the last year sniping at each other in the press.

The Steelers have come back from their 2–6 start and are now right behind the Bengals both in wins and in the DVOA ratings. Pittsburgh ranks 12th in the weighted formula, and Cincinnati ninth. Cincinnati needs to pass the ball to win this game, because while their passing game (second) and Pittsburgh’s run defense (fourth) are excellent, both the Bengals’ running game (17th) and Pittsburgh’s pass defense (15th) have declined since last season. Pittsburgh will play ball control, running all over the Bengals’ 26th-ranked run defense.

New England at Tennessee (1 p.m., CBS) is the other AFC game that might have import. The Patriots can move up to the third seed with a win and a Colts loss to Miami. But that doesn’t present them with an easier opponent in either the first or second round of the playoffs, so Bill Belichick will probably rest his starters and give third-string quarterback Vinny Testaverde a shot at extending his NFL record to 20 straight seasons with a touchdown pass. Even if they beat the Patriots, the Titans will need San Francisco, Kansas City, and Pittsburgh to win if they want to become the first team ever to go from 0–5 to the postseason.

The most important game in the NFC is Atlanta at Philadelphia (4:15 p.m., FOX), since the Eagles will win the NFC East (and a first-round home game) with a victory. Atlanta’s greatest strength — its running game — directly threatens Philadelphia’s greatest weakness — missed tackles. But in every other area, the Eagles are a far superior team both on the field and in the clubhouse, where the Falcons are squabbling and head coach Jim Mora is on the way out.

If the Giants win Saturday night, only a complicated strength-of-victory tiebreaker can deny them the second wild card. But if they lose, the wild card may be decided by the season’s final game, Green Bay at Chicago (8:15pm, NBC). Chicago would be a heavy favorite if they had anything to play for, but the Packers will be fighting for their playoff lives against the Second City second-stringers. If the Giants lose, the Packers are in the playoffs with a win provided they haven’t already been knocked out by a particular combination of results involving Atlanta, Carolina, and St. Louis. Each of those teams also has a small chance of winning the wild card — and the right to get pulverized in Philadelphia or Dallas a week from now.

Mr. Schatz is editor in chief of footballoutsiders.com.