There are two big rivalry games on the NFL slate this Sunday, but the rivalries could not be more different. One is a geographical rivalry that matters more to fans than to players; the teams face each other every preseason but only once every four years in the regular season. The other rivalry is bitter both for the players involved and for two fan bases that despise each other. Two great quarterbacks lead teams with two opposing personalities that have met in both the regular season and the playoffs year after year.

INDIANAPOLIS COLTS (7-0) AT NEW ENGLAND PATRIOTS (6-1)
(Sunday, 8:15 p.m.)

The Patriots had beaten Indianapolis six straight times, but last year the undefeated Colts marched into Foxboro on the first Monday night of November and finally got the Belichick/Brady monkey off their back.

One year later, the undefeated Colts march into Foxboro once again, this time on the first Sunday night of November. Perhaps last year’s win gave the Colts renewed confidence, but that monkey is still in Foxboro, waiting to reattach itself.

Football is a game that is decided by the specific matchups of player against player and strategy against strategy. One cannot simply rank the teams 1–32 and say that a higher-ranked team should beat the one ranked lower. No matter how strong these two teams are at any given time, the matchups strongly favor the Patriots, because of how each quarterback contends with the opposing defensive scheme.

The Indianapolis offense excels in part because of Peyton Manning’s ability to read the defense before the snap and adjust the offense accordingly. But Manning historically has trouble adjusting against 3–4 defensive schemes, where the identity of the pass-rushers is far less clear. The problem goes far beyond the Patriots: San Diego handed Indianapolis its first loss of the 2005 regular season, and Pittsburgh knocked the Colts out of the playoffs. In both games, the linebackers in a 3–4 scheme completely overwhelmed the Indianapolis offensive line. The Colts even have a habit of playing close games against inferior teams that play a 3–4 defense (Browns, Jets).

Tom Brady, meanwhile, has an excellent record against Indianapolis and other teams which play “Tampa-2” zone coverage. On Monday night, he moved the Patriots down the field over and over, consistently finding his receivers in holes between Minnesota defenders. Buffalo now plays this scheme, and Brady has beaten them twice this year. Last year, the Patriots dispatched the team that gave this defense its name, the Buccaneers, by the score of 28–0. Even last year, the Colts stopped the Patriot running game but couldn’t stop Brady: He was 22-for-33 with 265 yards, three touchdowns, and no interceptions in the loss.

This year, of course, the Colts won’t be stopping the New England running game. The improved defense that helped the Colts finally beat the Patriots last year is a distant memory. In fact, the Indianapolis run defense is not just bad but historically bad. Colts opponents are averaging 5.4 yards a carry this season. In the last 35 years, only one team has allowed more yards a carry on the ground: the 1996 New Orleans Saints (6.1).The 2003 Kansas City Chiefs are the only other team since 1978 to allow even 5.0 yards a carry.

When these teams played last year, Patriots running back Corey Dillon was hampered by nagging injuries. This year, he’s fully healthy and part of a potent 1–2 punch with Laurence Maroney, one of the leading candidates for rookie of the year. Also healthier and improved this season are the Patriots’ defensive backs, which means the Patriots defense will present Manning with the challenge of years past rather than the picnic of 2005.

On top of all these trends on the field, the Colts will have to deal with the air floating above them. Like most dome teams, the Colts struggle in cold weather, but last year they lucked into a spot of Indian Summer in Foxboro as the temperature that night was 51 degrees. This year, the weather in New England will be more seasonal, with game-time temperature forecast to be just above freezing.

The idea that the Patriots completely shut down Manning is a myth; in the regular season, his numbers against New England are decent. But the Colts don’t win with decent quarterbacking, they win with Hall of Fame-level quarterbacking. Nothing below that will make up for the points that the Colts give away while Manning is on the sidelines.

KANSAS CITY CHIEFS (4-3) AT ST. LOUIS RAMS (4-3)
(Sunday, 1 p.m.)

Both Missouri teams have shared the same persona for years now: high-powered offenses, porous defenses. Both teams changed head coaches in the offseason, but only one changed its personality.

The Rams signed a number of big defensive free agents, and there was excitement after they held Denver to 10 points on opening day. Since then, things have returned to normal in St. Louis. 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 — rank the Rams sixth in offense and 25th in defense.

There have been many articles detailing the transformation of the Rams offense from the high-flying Mike Martz style to the run-oriented system of new head coach Scott Linehan. Yet the numbers show very little difference between the two. If anything, the current offense is less successful running the ball; the Rams were eighth in yards a carry last year, 22nd this year. Quarterback Marc Bulger has the lowest completion percentage of his career, yet has thrown just one interception. Something has to give: Eventually, some of those incompletes are bound to find the arms of defenders.

Kansas City’s drafts have concentrated on defense in recent years, and that unit took a big step forward this season, ranking 10th in DVOA against the run and 13th against the pass. The passing game is also strong, with backup Damon Huard playing surprisingly well after an opening week concussion knocked out started Trent Green.

Unfortunately, the running game expected to rank among the league’s best, instead struggled early. Larry Johnson has dropped from 5.2 yards a carry last year to just 3.7 this year, although he seems to be turning things around. The last two weeks he has 287 yards and five touchdowns against San Diego and Seattle, which are not great run defenses but aren’t terrible either. St. Louis ranks 26th in run defense, so Johnson’s resurgence should continue.

Research has shown that when two teams face each other in both the preseason and the regular season, the first half of the preseason game (when the starters play) is an excellent predictor of the regular-season result. In the first half of this year’s preseason meeting, Kansas City shut out St. Louis 16–0.

On the other hand, that game was in Kansas City, this game is in St. Louis, and both of these teams are known for enjoying a home-field advantage greater than the NFL norm.

Mr. Schatz is the editor in chief of FootballOutsiders.com.