The 2019 NFL season is approaching its halfway point. There’s an old saying that goes “defense win championships.” With plenty of data on NFL teams available after week six, it’s fair to take a look at some of the league’s defenses and evaluate which ones may be the best. Here’s a closer examination of the three best defenses in the NFL so far in 2019.

(All statistics are relevant as of games played on October 13, 2019, and are courtesy of ESPN.)

Chicago Bears

The Bears defense has been very good, but that’s not unexpected. In 2018, the Bears were third in yards allowed per game (299.7), first in points allowed (283), and first in points per game (17.7). Their defense was the main reason for their playoff push, which ended in a disappointing loss to the Philadelphia Eagles in the divisional round. 

This year, it’s been more of the same, though the numbers are better in some places and worse in others. This year, through five games the Bears are sixth in yards allowed per game (312.2), third in points allowed (69) and third in points per game (13.8). The Bears’ best performers on defense are linebacker Khalil Mack, cornerback Kyle Fuller, and defensive lineman Akiem Hicks. 

The second half may be tough sledding for the Bears. They face several high-powered offenses in the next few weeks including the New Orleans Saints, the Los Angeles Chargers, and the Philadelphia Eagles.

Division rivals like the Detroit Lions and Green Bay Packers will also be challenges. The other issue they face is their lack of offensive production. If Mitchell Trubisky and company fail to sustain long drives, it will keep the defense on the field longer and has the potential to wear them out. 

New England Patriots

Through six games, the New England Patriots have been an absolute revelation. They lead the league in points allowed (48), points per game (eight), and yards allowed per game (234.8). What’s been the key to their success so far? A few factors: 

• The Patriots are led by head coach Bill Belichick. You may have heard of him. He’s only one of the greatest defensive minds in the history of the sport. 
• They’ve faced a relatively easy schedule. They’ve been able to feast on the New York Jets, Miami Dolphins, New York Giants, and the Washington Redskins. None of those teams will remind anyone of the old school St. Louis Rams and their “Greatest Show on Turf.” 
• They’ve been devastating on third down. Offenses going against the New England defense have a third-down conversion rate of 13.37%, easily the best in the league. 

Their schedule only gets harder from here, but it’s a good bet that the most professional team in the NFL will continue to deliver above-average results throughout the remainder of the year. The only question is, can they maintain this level in January? 

San Francisco 49ers

The San Francisco 49ers have been the talk of the league this year, and it’s not only due to Kyle Shanahan’s offensive wizardry. The defense has been one of the best in football. The Niners are currently second in yards allowed per game (234.7), second in points allowed (64), and second in points per game (12.8).

Last season, injuries decimated San Francisco, but they’ve rebounded to become a complete team. How have they done it so far? According to the San Jose Mercury News, it’s been by making consistent plays they didn’t make in 2018: 

“Sacks and turnovers have become an expected staple from a 49ers defense that couldn’t muster them last season, when they set NFL records for only two interceptions and seven takeaways.

Third-down conversions allowed over the last three games: Steelers, 3-of-12; Browns, 1-of-11; and, Rams, 0-of-9. Sunday brought fourth-down stops, and a goal-line stand that had defensive coordinator Robert Saleh beaming, no, exploding with pride.”

If the Niners can keep this up, they can expect to represent the NFC West in the playoffs and may have a Super Bowl berth on the horizon.