The San Antonio Spurs have built one of the NBA's most feared defenses. Victor Wembanyama's MVP-level play has drawn the most attention. However, Stephon Castle's emergence as one of the league's top on-ball defenders has been an elite compliment to the French superstar.
“[Stephon] understands his role very well. The level he’s playing at is really unseen for a second-year player,” Wembanyama said of Castle's defense. “We make it uncomfortable for people playing against us. That’s the goal. Having to dribble around one of the best on-ball defenders and then having to shoot a shot over some of the best rim protectors, that’s very tough.”
The Spurs have the NBA's third-best record (43-16) amid a league-best 11-game winning streak. Castle's two-way contributions during his second season have expedited San Antonio's timeline.
The 21-year-old has been solid offensively, averaging 16.6 points and 6.8 assists on 46.7 percent shooting across 49 appearances. However, Castle's success in an expanded defensive role has been the catalyst behind his impact.
Stephon Castle blossoming as defensive stopper with ascending Spurs
San Antonio has tasked Castle with defending the league's top scorers nightly. The 6-foot-6 guard has met the challenge and then some, leading a defensive unit alongside Wembanyama that ranks third in the NBA.
Castle has posted a -4.7 defensive rating swing (team points allowed per 100 possession with a player on vs. off), the NBA's sixth-best mark among guards who have played over 1,000 minutes, per CleaningTheGlass. The Spurs have posted a 109.3 defensive rating with him and Wembanyama on the floor.
San Antonio held MVP candidate Cade Cunningham to 16 points on 5-of-26 shooting during Monday's 114-103 win over the Detroit Pistons. Cunningham shot 3-of-13 (23.1 percent) with two turnovers when defended by Castle.
“[Stephon] showed potential for it last year,” Spurs head coach Mitch Johnson said. “He had some really good moments defensively. This year, we’ve obviously upped the ask, which has upped his opportunity to guard the big-time scorers and guys who dominate the ball in this league. And I think he’s proven his capabilities. I think he has to continue to grow off the ball in other ways. But I think on-ball he has been as good as anybody in the league.”
Stephon Castle defense on Cade Cunningham during the Spurs win over the Pistons
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With Castle and Wembanyama already wreaking havoc on opposing offenses, the Spurs have another potential elite on-ball stopper in rookie Dylan Harper. At 6-foot-5, 215 pounds with a 6-foot-10.5 wingspan and above-average athleticism, the No. 2 draft pick has caused problems for opposing ball-handlers at just 19 years old.
Harper is learning on the job while backing up Castle.
“The biggest thing about Stephon is he's a competitor. I saw that early when I got to San Antonio,” he said. “He's gonna compete no matter what the situation or who he's going up against. On the biggest stages, all the work he's put in is showing. Him being physical [at the point of attack], having elite wings and other guards, and then you have Victor and Luke [Kornet] down at the rim, it's like pick your poison. You either gotta shoot this pull-up or kick it out.”
The Spurs are currently tied with the Cleveland Cavaliers for the third-best odds (+950) to win the title, trailing only the Denver Nuggets (+600) and Oklahoma City Thunder (+135). Wembanyama, Castle and Harper will each still be on their rookie contract next season.
