Kansas City, Mo. — The only defense the Kansas City Chiefs played most of this season was, well, in defense of their own defense, which gave up so many yards and points that it became a running joke around the league.

Yes, the Chiefs scored in bushels. They also allowed points in bunches.

The fact that they spent most of the season coughing up 30 points and 400-plus yards per game came despite the fact that they excelled at sacking the quarterback. They finished with 52 of them, tied for the NFL lead, thanks primarily to the trio of Chris Jones, Dee Ford and Justin Houston.

Yet things began to change in Week 17, when the Chiefs shut down the Oakland Raiders in a game they needed to win to secure the No. 1 seed in the AFC. And when critics claimed that the Raiders were playing for nothing, the Chiefs backed it up with a defensive gem in the divisional round against the Colts.

Now, that suddenly stingy defense gets its biggest test Sunday against Tom Brady and the New England Patriots.

At stake: A trip to the Super Bowl, the first for the Chiefs in 49 years.

So what changed? How did a Swiss cheese defense that was torched by the Patriots for 43 points in a Week 6 loss in Foxborough suddenly turn into a steel curtain, and just in the nick of time?

“In the last couple of games, the three things we’ve done is we’ve limited the explosive plays, we’ve done a really solid job of tackling and we’ve had one defensive penalty in two weeks,” Chiefs defensive coordinator Bob Sutton said. “Those three things allow you to function and go.”

Take each one in order.

In the Chiefs’ four losses this season, they allowed four plays of 40-plus yards and 21 plays of at least 20 yards. Seven of those came in a particularly dismal defensive performance against the Rams, who ultimately won a 53-50 shootout at the Coliseum in Los Angeles.

But the Chiefs didn’t allow a single play over 15 yards against Oakland, and didn’t allow the Colts a play over 30 yards. In fact, Indianapolis didn’t score on offense until late in the fourth quarter.

Their success in limiting big plays is, at least in part, a byproduct of improved tackling.

Then there are the penalties. After leading the league in total penalties and defensive penalties this season, their defense has been flagged just once over the past two games.

“Most points that are produced in a drive usually result from an explosive play and-or a penalty in the drive,” Sutton explained. “The common thing when you look back and say, ‘Hey how’d they get down the field?’ It’s usually you had a (pass interference) here or you gave up a 20-yard run here or whatever it was. So, if you can manage those and do a relatively good job on those things, you put yourself in a good position to play. I think the guys that have played have done a good job.”

Ah, there’s the caveat: The guys who have played have done a good job.

The Chiefs have been missing pieces on defense the entire season, and often they have been crucial playmakers. Highly paid linebacker Justin Houston, who had a pair of sacks against the Colts, missed four games with a hamstring injury. Top cornerback Kendall Fuller missed a game with a broken hand. Starting safety Daniel Sorensen missed half the season with a broken leg.

Those injuries alone are enough to derail any defense, but the Chiefs have also played almost the whole season without Eric Berry, their star safety and arguably the team’s emotional leader.

He played in just two games because of his heel but is poised to play Sunday against New England.

“That’s my guy. Eric Berry has kind of taken me under his wing since I got here,” Chiefs cornerback Steven Nelson said. “We call him ‘Coach’ in our room because he’s so knowledgeable. He means a lot to our team and our defense, so whenever we can have him out there, it’s a great thing.”

The Patriots are under no preconceptions the defense they marched up and down the field against in Week 6 will show up on Sunday. Bill Belichick said this week that there is little to glean from that win, while Brady was quick to heap praise on a defense playing its best all year.

“We’ve played them quite a bit over the years,” the Patriots quarterback said. “They’ve had some incredible units that we’ve played against. They’ve got playmakers at each level. Obviously, a good scheme. They make you work for it. It’s a very tough, hard-nosed team. They compete on every snap. They’ve been in a lot of close games this year. It’s a great challenge for us. I don’t think you can take anything for granted.”

Talib is Rams’ cornerstone

The Los Angeles Rams realize they’re heading into one of the NFL’s most intimidating environments when they visit the top-seeded New Orleans Saints in the deafening Superdome for the NFC championship game.

Leave it to Aqib Talib, their voluble veteran cornerback, to remind his teammates about the upside of the New Orleans fans’ famed investment in the game.

“As a defense, man, we like playing in it,” Talib said. “It’s going to be quiet (when the Saints have the ball). We can talk. We can communicate good, so as a defense, we enjoy it.”

That’s exactly the type of vocal, clever leadership the Rams desired when they acquired Talib last spring to bolster a defense lacking in big-game experience. They’ll need every bit of Talib’s expertise and skill when they attempt to slow Drew Brees, Michael Thomas and a New Orleans offense that already carved up the Rams (14-3) once this season.

The Rams have one significant reason to think the rematch will be better: Talib was out with an ankle injury two months ago when the Rams gave up 346 yards passing to Brees during their first loss of the season, 45-35 at the Superdome.

Talib is healthy and eager to make a difference Sunday, although he deflects any attempt to put the spotlight on him.

“Everybody is preparing for this game different,” Talib said. “This is a huge game, so everybody is having real sharp meetings, and we’re all going to bring something a little different to the table.”

The Rams acquired Talib and Marcus Peters to be the shutdown cornerbacks needed in the schemes of defensive coordinator Wade Phillips, who also coached Talib with the Broncos. Los Angeles even gave up linebacker Alec Ogletree, their leading tackler for most of his career, to create the cap space necessary to get Talib in a trade.

While many of his teammates got their first career playoff victory last week against Dallas, Talib has seen it all before — from big playoff games in New England to a Super Bowl championship run with Denver. The 32-year-old cover specialist was named a captain by his teammates before he had even played his first game with the Rams, although he downplays his own leadership role.

“I just be myself, you know,” Talib said. “I just communicate with guys, ask questions in the meeting room, and I don’t know. Maybe if I was on the outside looking in, I would see it.”

Los Angeles’ defense has experienced a clear upswing in performance since the Rams’ epic 54-51 victory over Kansas City in late November. The Rams’ defense forced five turnovers by the Chiefs, but also gave up 546 yards.

That was the eighth game missed by Talib due to a high ankle sprain. He returned for the next outing after their bye week in early December — and not coincidentally, the Rams have held four of their last six opponents under 23 points.

“It changes things,” Phillips said. “Since Aqib has been back, we haven’t given up a lot of big plays in the passing game. He helps with communication, he helps with his talent, and we don’t have to change people around to cover up for a guy that hadn’t been playing. It gives us a versatility that we didn’t have when he wasn’t in there.”

Phillips typically doesn’t like to assign one cornerback to a single receiver, preferring versatility and flexibility. The Rams also have a strong third cornerback, Nickell Robey-Coleman, who typically handles receivers lining up in the slot, as Thomas sometimes does.

But it seems highly likely the Rams would consider matching up Talib with Thomas as much as possible. After all, Thomas posted 211 yards receiving against his hometown team in November largely against Peters .

Talib understandably wouldn’t give away the Rams’ potential strategy for the NFC title game, and neither would Phillips. But Phillips made it clear how much he relies on the veteran to act as an extension of himself on the field.

“He’s pretty proactive about everything,” Phillips said. “He’s a big personality, so you can’t help but be drawn to him. I tell him he always takes the other side. Whatever side you take, well, he’s going to argue the other side. You know, that’s him. He gets going, he gets excitable about a lot of things, and he’s a lot of fun to be around. And he made me drippin’ in the Super Bowl, so that was nice.”