Chiefs and Falcons are NFL’s last 2 unbeaten teams. Are they the real deal?

It’s rare to just have two unbeaten teams remaining going into the fourth week of an NFL season. This season, it’s just the Kansas City Chiefs and the Atlanta Falcons left standing.

That’s the fewest number of undefeated teams through three weeks since 1985, with the exception of 1987, during the last NFL players’ strike. And while there’s still a lot of football to be played, both of these teams look like legitimate contenders.

The Chiefs shocked the world with an upset win over the Patriots in the season opener. It wasn’t just a victory — it was a 42-27 beatdown in Foxborough. Kareem Hunt shined in his NFL debut with 246 combined yards and three touchdowns. Alex Smith became only the second quarterback to throw for 300 yards and four touchdowns against the Patriots in a game during the Bill Belichick era. If ever there was a signature win, it was this one.

The Falcons had their own statement win in Week 2 in an NFC Championship rematch against the Green Bay Packers, and their young defense played a big part in the 34-23 win. Desmond Trufant was named the Sunday Night Football player of the game after picking off Aaron Rodgers and recovering a fumble for a scoop-and-score.

NFL experts — at least the ones here at SB Nation — are confident that both of these teams can keep the streak going in Week 4. Our writers unanimously picked the Falcons over the Bills and the Chiefs over Washington this week.

There’s a lot of football still to play this year, but these teams look like the class of their respective conferences. Who knows? Maybe these last two undefeated teams will end up meeting in Super Bowl LII.

Kareem Hunt is one of the main reasons the Chiefs are going to be difficult to stop this season. No defense has been able to even slow him down yet. He’s averaging a ridiculous 8.5 yards per carry, and opponents are finding out about his tendency to make big plays the hard way. He’s the first player in NFL history to have a 50-plus yard touchdowns in each of his first three games.

Tyreek Hill is always a threat to leave defenders in the dust. And Alex Smith has a better quarterback rating than anyone else in the league except for Sam Bradford, who has only played in one game this season. Smith has completed 77.4 percent of his passes and averaged 258 yards per game with seven passing touchdowns and no picks.

On the other side of the ball, the Chiefs are giving up an average of 369 yards per game, which ranks them near the bottom of the league. But yards don’t win games — points do. The Chiefs are stingy with those, allowing just 19 per game. They’re also ranked second in the league with 11 sacks so far this season.

The AFC West is shaping up to be one of the tougher divisions in football, and Kansas City still has two games each against the Raiders and the Broncos coming up. It won’t be an easy road. But Denver and Oakland both suffered unexpected losses last week, and they face each other this week, so one of these teams is about to fall to 2-2.

Still, we’re just three weeks in here. It’s not the first time the Chiefs have gotten off to a rolling start. The last time it happened, they fizzled out. Kansas City went 9-0 to start the 2013 season, and then totally fell apart after a Week 10 bye. The Chiefs lost five of their last seven games, and blew a lead in wild card action against the Colts to lose a 45-44 heartbreaker. But that doesn’t change that this year’s team looks ready to contend.

Verdict: Barring injury, the Chiefs should stay in the mix for the top spot in the division. Smith is playing well and Hunt and Hill are nearly impossible to contain. An aggressive defense makes Kansas City a well-rounded threat.

That Super Bowl hangover analysts talked about all offseason never materialized for the Falcons. The departure of offensive coordinator Kyle Shanahan hasn’t had as big of an impact as fans feared. Matt Ryan’s stats aren’t quite as gaudy this season under new offensive coordinator Steve Sarkisian, but the Falcons are averaging 41.43 yards per drive and 2.86 points per drive, according to Football Outsiders. That places them at the top of the league.

The Falcons’ one-two punch at running back is a factor. Devonta Freeman is living up to the expectations set by the five-year, $41.25 million extension he signed before the season. Tevin Coleman is also a bona fide threat, as a runner and a receiver. Ryan’s still able to spread the ball around, which is easier when you have talent like Julio Jones to work with.

But the biggest story in Atlanta is the development of its young defense. That may be the factor that lets the Falcons take control of the conference this year.

Even with Vic Beasley, the NFL’s sack leader last season, sidelined with a hamstring tear, the Falcons have managed to get opposing quarterbacks off their spot. They’re tied for 10th in the league with nine sacks, and a rotation of players, including Adrian Clayborn, rookie Takk McKinley, and Brooks Reed, have been able to pressure quarterbacks from all over the place.

This side of the ball is young, but the four rookies who were starters last season — strong safety Keanu Neal, linebackers De’Vondre Campbell and Deion Jones, and nickel back Brian Poole — all are playing faster and more aggressively after one more season in the system. They’re hovering at No. 18 in the NFL for points allowed with 22 and are 15th for yards allowed with 330.7 per game. But they’re eighth against the run, with just 85 yards per game.

The Falcons jumped out to a 5-0 start in 2015, which was Dan Quinn’s first season as head coach. They ended up 6-1 in their first seven games, with only a loss to the Saints on their record. Then they hit a six-game skid and finished the season 8-8. But this team is just a few months removed from a Super Bowl appearance, and the offensive consistency and defensive improvement are good signs.

Verdict: The offense doesn’t seem to have lost a step under Sarkisian. The defense isn’t likely to be a top unit this season, but they’re improved over last year. All they need to do is pressure quarterbacks and give the Falcons offense a chance to outscore opponents. If they keep that up, the conference should be Atlanta’s for the taking.