It was roughly 2:30 p.m. on Sunday when this strange combination of letters and numbers scrolled across the score ticker on the bottom of America’s television screens: “Indianapolis 14, Houston 14.” NFL fans perhaps thought the networks were having some sort of technical difficulty, but that was actually the halftime score between the undefeated Colts and the winless Texans.

How did Houston, which eventually lost 38-20, keep things close for 30 minutes? Just take a quick look at the stat sheet. In the first half, 26 of Houston’s 32 offensive plays were runs. The explanation was simple: Despite their 7-0 record, the Colts still cannot stop the

run, and it is an Achilles’ heel they share with several other contenders.

The Colts rank 16th according to the NFL’s official stats for rushing defense, but those stats are based on total yards per game, and Indy’s opponents have to stop running when the Colts establish a big lead. Based on a more accurate measurement, yards per carry, the Colts are 27th in run defense.

In fact, Indianapolis is one of three teams that ranks among the NFL’s 10 best pass defenses based on net yards per pass, but also among the NFL’s six worst rushing defenses based on yards per carry. And while the inability to stop the run did not cost the Colts a win on Sunday, the other two teams, Cincinnati and Buffalo, were not so lucky.

The Bengals gave up a combined 222 yards to three Pittsburgh running backs in their 27-13 loss. The Steelers attacked Cincinnati’s weakness by running 47 times and passing just 15. In Oakland, LaMont Jordan and Zack Crockett combined for 155 yards and four touchdowns as the Raiders trampled the Bills, 38-17.

When the Colts opened the season by holding opponents to a combined 29 points through the first five games, most NFL analysts assumed their defense had improved across the board. But the Colts are playing the same defensive style this year as in years past – a style that hides their weakness against the run, only to expose it when they can least afford to falter.

Head coach Tony Dungy prefers smaller, quicker defenders who can swarm the quarterback with a pass rush and make big plays in the secondary. But these smaller defenders generally have trouble tackling running backs, and have a tendency to be too quick, leaving open cutback lanes for runners. Dungy also prefers a modified Cover-2 zone coverage that moves the middle linebacker further back into coverage – and away from any running play – in an attempt to take away the zone in the middle of the field.

Oft-lauded defensive end Dwight Freeney is the perfect example of the Colts’ mindset. Freeney is the most significant defensive force in the NFL today, usually requiring a double- or even a triple-team. Hand the ball to a back up the middle, however, and Freeney becomes useless by taking himself out of the play thanks to his zeal for sacking the quarterback.

This style of defense is an excellent match for the explosive Colts offense. The Colts are used to Peyton Manning putting them up by two touchdowns early. Once the other team has to abandon the running game, that swarming defense can rack up the sacks and turnovers, leading to the kind of blowout losses we’ve seen in the last two Denver-Indianapolis playoff matchups.

Sunday in Houston, the Colts finally snuffed the Texans’ running game by pulling ahead in the third quarter. After running 26 times in the first half, Houston ran just seven times in the second half. After sacking quarterback David Carr just once in the first half, the Colts sacked him four times in the second half, and he fumbled three times.

But what happens when another team can keep Manning somewhat contained for an entire game? We’ve seen the answer every time the Colts play the New England Patriots. If an opponent can keep the game close in the second half, it can run on the Colts with impunity, gaining yardage, tiring out the defense, and keeping Manning off the field.

That’s what happened to Cincinnati on Sunday. The Bengals and the Colts play a similar style of defense, only the former have a better secondary but no Hall of Fame-quality pass rusher. Over and over against Pittsburgh, Bengal defenders over pursued the initial direction of the play, leaving the holes they were supposed to fill wide open. Midway through the third quarter, Pittsburgh running back Willie Parker wound his way through missed tackles for a 37-yard touchdown run that put the Steelers up 17-6.

At that point, Pittsburgh had rushed for 125 yards on 21 carries to go with 11 pass plays. From that point on, the Steelers ran 24 running plays and just four pass plays. In the fourth quarter, Pittsburgh kept the ball for more than 10 minutes on two drives that gained 89 yards without a single pass. In the past three weeks, the Steelers, Titans, and Jaguars have all registered their season high for rushing yards against the Bengals.

Both the Bengals and the Colts made moves in the off-season to fix the problem, but to no avail. The Colts picked up ex-Philadelphia tackle Corey Simon immediately before the season, but he still doesn’t seem to have played himself into shape. The Bengals spent their first two draft picks on players for the front seven, but outside linebacker David Pollack is more of a pass rusher, and inside linebacker Odell Thurman is similar to his Indianapolis counterpart Gary Brackett: great in pass coverage, repeatedly run over by ball carriers.

Buffalo is a different story. Unlike the Colts and the Bengals, the Bills have a poor offense, so they can’t mask their defensive deficiencies by jumping out to early leads. But unlike the Bengals and Colts, the Bills actually had one of the league’s best run defenses last year, allowing just 3.6 yards per carry. That has ballooned to 5.1 yards per carry this season. Many have blamed the departure of widebody defensive tackle Pat Williams, but his new team in Minnesota can’t stop the run either. A bigger culprit is the loss 1135 1329 1253 1341of linebacker Takeo Spikes for the year; the Bills gave up a yard less per carry before his injury in Week 3.

Every year at playoff time, Peyton Manning faces a team that can keep him in check. This year will be no exception, even if that team isn’t the Patriots. When that happens, all those regular season wins won’t keep the other team from running the ball. The Colts defense will have to do what they haven’t done in years past, and what they haven’t done this season either: step up and stop the ground game.

Mr. Schatz is the editor in chief ofFootballOutsiders.com.