Kansas City Chiefs

Biggest Weakness: Rush Defense

Generally speaking, if your biggest deficiency is stopping opposing ground games, you're probably doing all right. Passing efficiency is much more important in deciding wins than what teams do on the ground, so if you're going to pick an area to struggle, it should likely be this.

The Chiefs just take it to the extreme.

Their defense finished the regular season ranked dead last in Adjusted Defensive Rushing NEP per play, which does take into account the schedule they faced. They allowed a 100-yard rusher each of the final two games of the regular season, and teams have used these struggles as a way to neutralize the Chiefs' offense.

The best example of this is back in Week 6 against the New England Patriots. In that one, the Patriots were aggressive on the ground, running a total of 38 times. Because this takes more time off the clock than a pass, it keeps the Chiefs' offense off the field longer. The Chiefs wound up running only 53 plays in that game, tied for their fewest of the entire season.

If you're facing a superior foe, your best shot at winning is to cut down the sample size. Most teams are going to be inferior against this Chiefs team, meaning you want that sample size as small as possible. The Chiefs' offense is good enough to overcome this, but if teams decide to pound the rock against them, it will increase the already-high variance that comes with single-loss elimination. If the Chiefs face either the Los Angeles Chargers or the Baltimore Ravens in the second round, expect them to see a heavy dose of the opposing team's ground game.

New England Patriots

Biggest Weakness: Pass Defense on the Road

There are a couple of things ailing this version of the Patriots. Specifically, they could struggle without the services of Josh Gordon as Tom Brady's efficiency numbers when targeting Gordon were far beyond what he has gotten out of most of the team's other pass-catchers. But even more concerning is how drastic their home-road splits are defensively.

Here's a look at what quarterbacks have done against the Patriots this year based on where the game has been played. "Passing NEP/P" is short for Passing NEP per drop back, which measures the expected points added on each drop back while deducting for expected points lost on events such as sacks, incompletions, and interceptions. "Success Rate" is the percentage of drop backs that increased the team's expected points for the drive.

That's bad enough as it is. But that sample of quarterbacks outside of New England includes such prolific passers as Blake Bortles, Derek Anderson, Josh McCown, and Ryan Tannehill, all of whom finished with negative Passing NEP marks for the full season. They're not going to see someone like that in the playoffs.

Thankfully for the Patriots, the earliest they would have to worry about this is the conference championship. If the Chiefs were to get knocked off in the divisional round, it wouldn't happen until the Super Bowl. This isn't to say that the Patriots are out of the woods -- again, their pass-catchers leave plenty to be desired -- but their odds of getting back to the Super Bowl may not be as long as they seem.

Houston Texans

Biggest Weakness: Pass Protection

The Houston Texans' offensive line is putrid across the board. They rank 27th in adjusted line yards, according to Football Outsiders, explaining why Lamar Miller has struggled so mightily since coming over. The big concern, though, is their ability to keep Deshaun Watson from getting banged around.

Before delving into that more, it's worth noting that all of the blame doesn't belong to the offensive line.

For some of the sacks, Watson deserves blame. Let the record reflect as much.

But just for a second, let's take away the 14 sacks that Watson was allegedly responsible for. Even when we do that, the Texans still would have allowed the ninth-most sacks in the entire league. If you get sacked 62 times, and only 14 of them are on you, that's probably not a bad ratio.

For the season, the Texans lost a whopping 95.11 Passing NEP due to sacks. That's the fourth-worst mark in the league once you adjust for the number of total drop backs that Watson had. Only one team worse than them made the playoffs (more on them in the section on the NFC). This could cause issues.

The beneficial thing for the Texans is that it won't play a major role right away. They face the Colts this week, and their defense ranked 22nd in Sack NEP per drop back. If the Texans win, they'd face the Patriots, who were 31st. It wouldn't be until a potential matchup with the Chiefs (sixth) that they would face a team that can truly get after the passer. Still, even if this isn't an extreme concern now, with how easily a sack can kill a drive, it'll be one that could very well put a lid on the Texans' ceiling this year.

Baltimore Ravens

Biggest Weakness: Passing

There is no doubt that Lamar Jackson has been a thrill to watch, and without him, they're probably not playing this Sunday. But if the Ravens wind up falling behind, they could be in some trouble.

As a passer, Jackson finished the year ranked 32nd in Passing NEP per drop back out of 43 quarterbacks with at least 100 drop backs. Compared to his fellow rookies, this isn't bad, and it should make the Ravens excited about what they've got in this guy. But when compared to other quarterbacks in the playoffs, it's a short-term issue.

In terms of Passing NEP per drop back, Dak Prescott is the second-worst quarterback still kicking, finishing the regular season ranked 23rd in that metric, a good chunk ahead of Jackson. Next on the list is Nick Foles all the way up in 15th. This hasn't mattered because the Ravens have led so often with Jackson at quarterback (often because of Jackson's skills), but at some point in the playoffs, they're going to need to make up ground.

Since becoming a starter, Jackson has just 57 drop backs to his name while trailing compared to 116 when leading or tied. We're going to see what he can do when forced to chuck it eventually, and the Ravens will have to hope the passing results trend up a bit from where they were in the regular season.

Los Angeles Chargers

Biggest Weakness: Schedule

It's legitimately hard to pick a weakness for the Los Angeles Chargers. They rank fifth in overall schedule-adjusted offense, third through the air, and their defense is in the top 10 against both the pass and the rush. For a 5 seed, they're crazy strong. It just may not matter with the road that lies ahead of them.

Because the Chargers couldn't quite snag the AFC West, they get to open on the road against the Ravens. The Ravens already knocked them off in Week 16, and that game was in Los Angeles. Facing the league's top-ranked defense on the road isn't a fun assignment.

But even if the Chargers do win there, their next game would likely be on the road against the Chiefs. The Chargers did win there once already this year, but the Chiefs allowed an average of 18.0 points per game at home this year compared to 34.6 per game on the road. Beating them a second time in Arrowhead would be a tall ask.

The best hope for the Chargers would be for the Colts to defeat the Texans this weekend, which is very much a possibility. That would allow the Chargers to play the Patriots in the divisional round instead of the Chiefs, postponing that date in Kansas City until the AFC Championship Game. It's a tough draw for a team that won 12 games in the regular season, but with how good the Chargers have been, they may still be able to overcome it.

Indianapolis Colts

Biggest Weakness: Pass Defense

The Colts play a particular brand of defense where they do whatever they can to prevent big plays. It was a successful strategy as they allowed the seventh-fewest plays of 20 or more yards in the league this year. But good quarterbacks were still able to take advantage.

For the full season, the Colts finished 23rd in Adjusted Defensive Passing NEP per play. They played only four games against quarterbacks ranked better than 15th in Passing NEP per drop back (two of which were by Watson, whom they will face this week). Both Watson and Tom Brady threw for more than 340 yards against them, and both scored at least three total touchdowns in those meetings. Even more questionable passers found success as Bortles and Eli Manning threw for 300 yards against the Colts in Indianapolis.

This week, the Colts face Watson, who was 14th in Passing NEP per drop back. If they win, they would face Patrick Mahomes, who was first by a pretty solid margin. The Colts may be able to neutralize the big-play abilities of both offenses, but that doesn't mean we should expect them to completely bring either team to a halt.