The AFC has an established hierarchy. The New England Patriots have appeared in the title game in five consecutive seasons, and teams only become legitimate AFC contenders after proving they can defeat the Pats. Denver has beaten New England three of the last four times the teams have played — including in last year’s title game — and won the AFC West in five straight seasons. And whichever team emerges from the top-heavy AFC North can’t be ignored, either: Baltimore won the Super Bowl four seasons ago, the Bengals have won 44 games since 2012, and the Steelers look like the second-best team in the AFC.

Two other teams are threatening to break into the AFC’s upper crust, and they happen to face off in Week 2. Kansas City has won 11 consecutive regular-season games, the longest active streak in the NFL. Houston finished 2015 on a hot streak of its own, winning seven of its final nine games; after an opening-day win in Chicago, the Texans join the Chiefs as the only AFC teams to win at least eight of their last 10 regular-season games. Yet despite those results, neither of these teams are viewed as part of the AFC’s top tier. And that’s because both teams are viewed as having relatively low ceilings. So the question for this season is, can either team raise its ceiling?

Houston’s struggles against top teams

For Houston, Sunday’s game will be serve as an early-season litmus test for whether the Texans have improved. In the season opener in 2015, Houston hosted Kansas City but were nearly run off the field in the first half; the Chiefs jumped out to a 27-6 lead and held on for a close win. Last year also ended with an embarrassing home loss to the Chiefs: The Texans were shut out, 30-0, in the team’s lone playoff game.

Struggles against the Chiefs are signs of a broader problem for Houston: Over the last two years, the Texans are 16-6 (a 0.727 winning percentage) against non-playoff teams, with two of those losses coming when backup quarterback Ryan Mallett was forced into action. Meanwhile, Houston is just 2-8 against playoff teams over that time frame (0.200), and that doesn’t include the loss in last year’s playoffs. That gives Houston a +0.527 winning-percentage differential advantage against non-playoff teams relative to playoff teams, the second largest (behind only the Lions) in the NFL over the past two seasons:

Houston’s struggles against stronger teams often come down to poor quarterback play, which was particularly evident in the team’s last two losses. Against New England in December, Brian Hoyer threw for just 101 net yards (after deducting yardage lost on sacks) on 27 dropbacks, and the Texans did not score a touchdown. That was just the appetizer: In the playoffs, Hoyer had, by one measure, the 4th-worst passing performance in NFL history in the playoffs, completing 15 of 34 passes for just 136 yards with 0 touchdowns and 4 interceptions.

The Texans were so desperate to improve the team’s passing attack that they signed Brock Osweiler to a massive contract, guaranteeing him $37 million, and then spent first- and third-round draft picks on wide receivers. And while an opening-week win over Chicago was nice, the Chiefs represent the first real test of whether Houston deserves to be viewed as one of the AFC’s best teams.

Kansas City’s horizontal passing game

For a Kansas City team that is on a franchise-record 11-game winning streak, a third win in Houston in 371 days probably won’t change the team’s perception in the eyes of most fans. Kansas City has mastered the art of the low-risk, medium-reward passing attack: Of the 32 passers with the most attempts from 2013 to 2015, Alex Smith’s 1.39 percent interception rate trails only Aaron Rodgers (1.37 percent) for the best in football.

But the safe passing attack comes at a cost: Among that same group, Smith ranks just 28th in yards per completion (11), and his sack rate (8.2 percent) ranks 7th-worst. This is by design. In 2013, Smith’s average pass traveled just 6.62 yards downfield, according to the NFL’s Game Statistics & Information System, which ranked 36th out of 37 qualifying passers. In 2014, his average was down to 5.83, dead last among the 33 qualifying quarterbacks. And last year, his average pass was at 6.73 yards, 33rd out of 34 qualifying passers.

The Chiefs’ low-variance passing game works when the defense and running game are effective, as they have often been during this streak. Over the final three-quarters of the 2015 season, Kansas City allowed by far the fewest points in the league, while the Chiefs led all teams in rushing efficiency as measured by DVOA last season.

But with superstar linebacker Justin Houston still recovering from offseason ACL surgery, last year’s top cornerback Sean Smith now in Oakland, and the team thin at inside linebacker, the team may ask for more from Alex Smith this year than ever before. That was the case in Week 1, when Smith threw a league-high 48 pass attempts and led the Chiefs to the largest comeback in franchise history. After a dismal start to the game last week — the Chiefs’ first six drives yielded one field goal and five punts — Kansas City scored five times, including four touchdowns, on the team’s final six drives.

Smith’s style didn’t change — his average pass traveled just 6.48 yards downfield, and running back Spencer Ware led the team in receiving yards — but it was an encouraging sign to see him lift the team that was struggling on defense. Before Sunday, the Chiefs had been just 1-13 since 2013 in games where the opponent scored at least 24 points. If the defense continues to struggle — and it might against this revamped Houston offense — the spotlight will continue to shine on Smith. Which could make Sunday a key test for him, too.