The NBA is a fickle league. It wasn’t so long ago that it seemed as though the sky was falling for the New York Knicks. In a three-week stretch between New Year’s Eve and an embarrassing home loss to the lowly Mavericks on Jan. 19, the Knicks went 2-9 with the 28th-ranked defense in the NBA. There were a few scattered injuries in there — Josh Hart missed seven of those games, Mitchell Robinson missed three — but it was a mostly self-inflicted funk. After a strong start to the season that culminated in an NBA Cup-clinching victory over the San Antonio Spurs in Las Vegas, the Knicks fell into old habits, got sloppy defensively, and nearly triggered a panic.

They’ve been the NBA’s best defense since. By a mile, in fact. The 3.3 points per 100 possession gap between them and the No. 2 Spurs in that window is bigger than the gap between the Spurs and No. 9 Rockets. Sunday gave the Knicks a shot at yet another marquee win over the Spurs, who, this time, entered their matchup with New York riding an 11-game winning streak. New York delivered its best defensive performance of the season en route to a 114-89 win.

The Knicks allowed just 89 points against a Spurs team with its entire roster available. It was the first time the Spurs were held below 90 points all season, and it made plenty of sense as you watched it. Few teams have both a high-end wing and a high-end big to throw at Victor Wembanyama, but between OG Anunoby and Mitchell Robinson, the Knicks could present him two completely different sets of problems. Jose Alvarado can exhaust opposing guards on the ball so Mikal Bridges can force turnovers off of it. Between their energetic guards, long wings and giant rebounders, the Knicks have always had the tools to at least defend adequately. Over the past six weeks or so, though, they’ve started putting it all together.

There was some shooting variance baked into this performance, of course. San Antonio made just nine of its 34 3-point attempts, and the Knicks have benefitted from great 3-point luck throughout this defensive renaissance, as opponents have made a league-low 32.6% of their 3-pointers during this 14-4 stretch. But virtually every element of New York’s defense was on point just as it has been for the past six weeks or so.

The Knicks gave up just 38 points in the paint in Sunday’s win. Only Boston has allowed fewer than New York in this stretch. They forced 22 turnovers on a Spurs team with the fifth-lowest turnover rate in the NBA. Sure enough, the Knicks are generating an extra turnover or so per game since their turnaround. The Knicks forced the seventh-fewest mid-range shot attempts in the NBA over the season’s first three months. They’ve forced the third most ever since, and they forced the Spurs into plenty on Sunday. Meanwhile, they’ve drastically cut down on the number of 3-pointers they allow, as they gave up the fifth-most in the league through our Jan. 19 cutoff while getting back to league average ever since. They’re even fouling less.

There haven’t been drastic roster or health changes in this window. Getting Jose Alvarado helped, of course, but they haven’t had Deuce McBride, who’s not expected back until around the beginning of the playoffs. The growth here has been internal, a team executing its vision and playing aggressive, connected basketball. 

“We had five guys on a string,” head coach Mike Brown told reporters after Sunday’s victory.

That’s been a problem for the Knicks for some time. The locker room was reportedly frustrated last season over some of the freelancing Karl-Anthony Towns is known for when things are going poorly. When the Knicks last played the Spurs, Brown even criticized the team for not sustaining defensive effort across the full game. On Sunday, they were ferocious.

The Knicks probably aren’t going to be the best defense in the NBA when the postseason arrives. The shooting numbers will flatten out, if nothing else. The defensive limitations of building a team around a too-small point guard (Jalen Brunson) and an inconsistent center (Towns) have been talked to death. But the goal here doesn’t need to be dominance. The Knicks have the NBA’s third-ranked offense. That’s where they’re built to win.

The defense just needs to do its part, and it’s more than done so over the past month and change. No offense is good enough to make up for the way the Knicks defended in early January. But when they’re locked in and executing, they have the size, the depth and the know-how to compete with the best teams in the NBA.