Stephon Castle’s Trainer Calls Spurs Star Best Perimeter Player in the NBA, Discusses Vigorous Offseason Workouts

Whether the footage consists of highlight reels or blunders, Stephon Castle’s trainer sends him detailed video analysis filled with praise and constructive criticism.

Olin Simplis also has challenged the San Antonio Spurs’ third-year guard with sand-dune workouts and with minimizing consecutive misses through 625 shot attempts.

Through that laudatory and critical lens, Simplis outlined Castle’s encouraging trajectory entering his third NBA season.

“I honestly think he’s the best perimeter player,” Simplis said.

Simplis spoke to R.org on why Castle should become an NBA All-Star and All-Defensive team candidate. Simplis also detailed how Castle has improved his shooting and conditioning after a strong second season ended with shooting struggles in the Spurs’ NBA Finals loss to the New York Knicks.

Editor’s note: The following one-on-one interview has been edited and condensed

Interview With Olin Simplis

Can you catch me up on what Stephon’s off-season work has entailed with you so far?

Simplis: “It’s been a lot of shooting. It’s been a lot of adjustments for us with them going so deep into the playoffs. I wouldn’t say we lost two months. But the year before, we were two months in by the time I saw him this offseason. So a lot of it was moving slow and not going full throttle. He had a long season. Then after the season, he took two to three weeks off. So we didn’t want to jump back in there and take a chance of having any injury. So it’s been a slow buildup in a short period. Now we’re starting to ramp it up a little bit as we get guys ready to go back to their destination. It’s been a lot of shooting focus, pace focus, shot-line pocket focus, off-the-dribble. Then it’s focusing from the gathers to the energy into the dribble and into the gather and the shot-line focus. With that, we’re starting to move a little bit. We’re starting to do it at game speed in the last week.”

Why have those areas been Stephon’s off-season focus?

Simplis: “Obviously, shooting overall in the NBA is at a premium. But with Steph, it’s also about making sure that we create the proper energy and synergy on every rep. He’s such a high-volume guy defensively that sometimes his sequence in his shooting patterns is off. So I think fatigue sets in. If you don’t have the proper energy from the ground through your shot line, sometimes the ball reaches the pocket later than it’s supposed to during your sequence. We wanted the ball in the shot line while his hips are still in a bent position.

A lot of times when guys fatigue, coaches will yell to players when they’re shooting short to use more legs. But in all my years, very rarely have I seen someone use less legs or less depth in their hips when they’re shooting the ball. What tends to happen is the transition from dribble to pick up to shot-line or even catch tend to slow up just a tad. So by the time that ball shows up to your shooting pocket, your legs are already fully extended. So we still want that ball in the pocket while he’s still coming from the crouch position, into his full extension and then into his jump. So the focus has been on the cadence of the dribble into the gather, and then gather through the shot-line. So we have the same sequence as much as we possibly can, whether he’s fresh or fatigued. If you noticed in some of his videos, naturally the arc changes. His arc is a little bit more pronounced. The shot then becomes a little bit more fluid. It’s not just upper-body based.”

I saw the video of Steph doing the ‘500 drill’ last year. Did he do that again this year? [The drill entails taking 500 shots and minimizing consecutive misses].

Simplis: “Yep.”

How did this year compare to last year with that drill?

Simplis: “I thought last year, we made some strides. But when it’s not locked in, you go back to your place. I get out there once a month. But depending on the travel schedule, there can be every three to four weeks or the beginning of another month where there’s an eight-week gap. So some of the habits weren’t locked in. But during the summer, while he is here, I thought he did a really good job with improving. So this summer, I felt he shot it better. But last year, he did a really good job as well. But when you’re with someone on a daily basis, and those habits are being enforced, you’re going to shoot it at a high clip. Once they become locked in and they’re part of your DNA, now we can grow. I think this summer, we’re going to evolve. We’re going to start the season at a better pace than we did last year. If you noticed midway through the season, he started shooting it at a pretty good clip. But in the middle of the season, we were able to see him get out there before the All-Star break. They had a week off, plus they were home. So we were out there. Then All-Star break was in LA, so he was out here. Then right after All-Star break, he had a little homestand. So he was able to really focus on shooting in the middle of the season. He made a pretty substantial leap in the second half of the year.

This year, we want to send him with the tools to create. When you’re a young kid, you want to have a routine. The sooner that you get to your routine, the better off you’ll be. Kevin Durant does all of his single-leg work, his balance, and his spin. Before he does anything else, that’s what he does. So with Steph, we have a few daily vitamins. We worked on that last summer. But in the first year or two, kids don’t lock in on it as we’d like. But I think this year, when he walks to the gym now, I don’t have to say anything. He does the daily vitamins. He makes sure he’s holding the arc. He’s making sure that he’s driving with the ball up to reach his shot line. There are a few things that we do before he steps on the court. He does that on his own. If he’s able to do that when he goes back to San Antonio, that’s huge. Before you step on the court, guys are doing different activation stuff. They do roll outs. They get prehab work. They get stretched. They get massaged. That’s the same thing with shooting, or any other skill. You want to have your daily routine that you do before you hit the court. We’ve given him a couple of things. He’s matured as a player. These things, if he holds onto them, we’ll see him have a really good start and continue to ascend in the shooting department.”

I presume some of you what you outlined have something to do with this. But to be clear, what do you think contributed to his shooting struggles in the Finals? Steph shot 37.7% from the field and 30% from 3. 

Simplis: “People have to remember that he went from his rookie year where he played a lot to his second year where his minutes increased and his role increased offensively and defensively. There’s an adjustment period. There’s an adjustment period to the usage rate. He finished the season with 16.7 points, 7.4 assists and 5.3 rebounds, while defending the best perimeter defender night in and night out. Then when that player is out of the game, he guards power forwards and centers as well. That’s not just on one possession. He’s guarding these guys for extended periods. So there is a level of conditioning that needs to take place. If you’re a two-way guy, you face the guys that are the primary scorer on each team and are not required to defend at the same rate that Steph Castle would. So they still have that energy output available for them to do what they do offensively.

So back to Steph, it’s about adjusting and building up his level of conditioning as the season goes on to handle increases with his usage offensively and defensively. How he shot last year, he’s a far superior shooter than what he showed in the Finals. But we’ll keep working. He can get better. He’s not a 38% [from the field] and 30% [from 3] guy. In the second half and in the playoffs, he wasn’t that. He had a couple of games in the playoffs that he didn’t shoot it that well. But for the most part, his percentage was better. In the second half of the season and most of the playoffs, he shot it from 38% from 3. So I’m expecting him to keep those numbers, and growing as we start that year.”

Going back to the ‘500’ drill, can you recall how many makes he had without missing consecutive shots?

Simplis: “This summer, we increased the volume. He didn’t miss two in a row that frequently. If he misses three in a row, he loses a point. If he misses two in a row, we take one point off one of the makes. So you have to make up for that make. One of his emphases was shooting off the dribble. If guys go under the screen, Steph will dribble and then go right up. If guys are trailing on the screen and it’s in a low drop, he’ll come off the screen and ready to pound and elevate. So after shooting 500, we went back and did ‘five spots’ for 25 makes. So it was a total of 625 shots. That was 125 shots off-the-dribble after we did our first 500.

Without missing two in a row, I think he made all of his first three racks. I remember he made 50 on the corner, 50 on the wing, and 50 in the slot. When he got to the fourth spot, he had a few times where he had to go backward. But those first three spots, he went through 150 shots without missing two in a row. In a lot of those, we were in the ballpark of 15 or 20 straight makes. You don’t get through that drill by just making every other one. That total creeps up on you, and then fatigue sets in. So we probably got through 150 shots with 25 misses total.”

How do you see him improving his conditioning given his two-way responsibilities?

Simplis: “We’re starting to push the conditioning a little bit right now. We didn’t do a lot early because he played into June. Then he went on vacation. The team told him to take three weeks off. When he came back, he started shooting. Then he took a family vacation. So there’s one thing that he’s doing this year that he didn’t do consistently last year. He’s not doing slides in the sand yet. But he’s been running in the sand dunes with us this summer more than he did last summer. That’s going to help with his conditioning, his mobility, and lateral movement. That’ll help everything.

So we’ve been running the sand dunes in Manhattan Beach once a week. Every Wednesday, we go there. He’s incorporated that this summer. Next summer, I’m hoping to increase that to two times a week. Those sand dunes are a gem. People fly out here to do it. I remember when I was younger, Barry Sanders would come out here in the offseason and run in the sand dunes. He would run patterns. Russell Westbrook would do the same thing. He grew up on those sand dunes. Every LA player has spent time on the sand dunes. It’s definitely a secret weapon.”

How did you see Stephon handle that challenge?

Simplis: “It’s one steep hill. It takes a really locked-in and dedicated person. Obviously, it’s not one of those things that you can cheat. Whether you run it, walk it or sprint, you will get a workout. So getting him out here was our biggest challenge. But once he got out here, he’s gotten it done. For the last three weeks, he’s been coming in consistently. That’s something that we’re going to have in his summer regimen moving forward. Last summer, we introduced it to him, and he did it one time. This summer, we made this part of what we do. He’s in a groove. This is something that I hope we continue to use every offseason. We up it as we go. It doesn’t put a lot of impact on your joints. It’s not hard. Just walking it alone consistently can change your athletic output.”

Wemby [Victor Wembanyama] and Castle work a lot together and watch film. Do you have any window of their work together?

Simplis: “No. I’m not around when they’re working. When they’re working, they’re in San Antonio. When I come out here, it’s pretty much Stephon, me and Carter Bryant.”

Understood. But you have a window into Stephon, since you’ve worked with him since his junior year in high school. Big picture, what has jumped out to you with his progression and his trajectory?

Simplis: “What has jumped out to me is that honestly I knew that he was a good defender. But I didn’t know he was this great of a defender. I knew he was very solid. I didn’t know he would be in the conversation, though. This isn’t a knock on anyone else. I don’t think this is me being biased by any stretch.

I think he’s the best perimeter defender in the NBA for multiple reasons. He’s able to guard one through five. I have to study him. So I send notes every game. He’s guarding guys like Julius Randle. In that Minnesota series, he went from guarding Anthony Edwards to Julius Randle. He guards Karl-Anthony Towns. In a couple games, he guarded [Nikola] Jokić for a full quarter. I don’t see any other point guard or perimeter player guarding centers and power forwards.

I think Jaylen Brown is phenomenal. I think the Thompson brothers are phenomenal. But I don’t think they carry Steph’s flexibility. He’s guarding one through five. He’s not just guarding on one possession on a switch. It’s actually part of his game. The Spurs put him on post players for extended periods. He does a remarkable job. He’s doing that sometimes in the same game. He’ll go from Shai [Gilgeous-Alexander] to Chet [Holmgren]. He’ll go from Jamal Murray to Jokić. He’ll go from [Jalen] Brunson to KAT.

If you show me another guard doing that, I’ll change my tune. But I honestly think he’s the best perimeter player. He’s 6’7. There are other guys that are a little bit smaller that do what he does with fighting over screens. There aren’t other 6’7, 215-pound kids that are doing it at the level that Steph is doing it. He should’ve been an All-NBA defensive player last season, one-thousand percent. But when you’re in year two, sometimes voters give it to guys that have been in the league a little bit longer. That has been the biggest surprise for me. I didn’t realize he was that good defensively.”

What’s your sense on what Steph’s chip is like given he’s made a lot of strides early in his career, but he had the All-Defensive team exclusion and came up short in the Finals?

Simplis: “It’s crazy. He has a big personality. He’s a great kid. But he’s also reserved. He has that internal fire. He doesn’t walk around and say, ‘I got to get on a Defensive team, and we got to win the chip this year!’ His work and commitment show me how great he wants to be. He has that quiet confidence. But as far as his future, I honestly feel that he can be one of the top point guards in the league now. I’ve had some bold predictions before. Obviously being in the gym with these guys gives me that background to say such a thing. When I was with Shai, I immediately thought that Shai was the best player in his draft class. Some people thought that I was crazy. Two MVPs later? He was in a draft class that was supposed to have a lot of generational-type talent, and I was blessed enough to be with him for his first five years in the league.

What I see in Steph is the same thing. I don’t know what other guard in the NBA can do what he is capable of doing. Then you add his size and athleticism to it. We’re trying to keep expanding his shooting. But we’re adding some of the post-bumps that Jalen Brunson does with getting downhill, utilizing his hips and turning his drives into pullups. Once Steph incorporates that consistently, cancel Christmas. The game can become so easy for him as he matures and grows.”

He’s doing all of this while playing with other talented guards with [De’Aaron] Fox and Dylan [Harper]. What has Steph been doing with the skill work you detailed that also prepares him to play with other good guards?

Simplis: “For sure. That’s why we do a lot of stuff both off the ball and on-the-ball. He’s doing swing-swing actions where he’s not on the ball and Wemby’s in the post. He may swing the ball or make a skip pass to an opposite wing. Steph is shooting off of that. He’s also attacking out of that to create opportunities. He’s attacking closeouts. We work on all of that. We also work on Steph playing on the opposite wing, and the ball is being passed to him from the nail. That represents the guard tandem attacking the paint and kicking it out to him. So catch-and-shoot is Steph’s first option. But he’s also playing off that. He plays off kickouts, spray outs, and the post-swing. It’s not just about him having the ball and shooting it as a first option. We work on second and third-option shots as well.

He’s prepared. That’s what makes him so great. He played with a loaded UConn team. He knows how to play a role. He also knows how to be the man. When it’s time to be the man, he knows how to share the spotlight. There are also times to put the foot on the gas. He works on all of that. Playing next to other great players is something that he’s never had an issue with doing. He maximizes the opportunities when they present themselves. He’s more than a willing passer. So I’m not concerned with the stuff that we’re doing. He’s always going to be that guy to get his teammates involved. There was a stretch when he had eight-plus assists a game. For a second-year guard, that is really impressive.”

What do you think makes Steph tick?

Simplis: “I know people made a stink about his turnovers in the playoffs and earlier in the year. But that comes from a place of being too unselfish. When he’s getting into the paint, he’s looking to kick it out. When there are times that he needs to take the shots, he’ll take the shots. Now the defenses will sag in. Those corner kicks and passes are open. A lot of his turnovers, the majority come from not being passive, but from being unselfish. Sometimes, you have to take those shots. That’s the adjustment. We talked about it all season. But those turnovers are not happening because he’s rattled or the defensive ball pressure is too much. He’s getting into the paint and being unselfish. That’s the biggest thing.

That’s an adjustment. He carried a super load. It’s not something that he can’t handle. But he’s handled a big load offensively and defensively.

Now he’s better for it. We’re definitely going to be more than ready this year. I think he was close to being an All-Star. He had a chance to be an All-Star last season. His Dad and I in his circle are the harshest critics. So we’re not going to let him get away with anything. But we also understand there are some things that come with the territory and there is always going to be a learning curve. But our job is to make sure that we shorten that curve.”

What are notable examples of how you call him out on things?

Simplis: “I will if I see something. I send film. I’ve learned as I’ve gotten older, I won’t send film after every game. I used to send film after every game. But every week, they’re still getting film from every game, good, bad, or indifferent. So he’s getting the ugly. If he makes mistakes, that’s popping up on his phone. I’m showing him what he could’ve done differently. We’ll slow the film down with arrows circled. He’s constantly getting feedback. One thing about him is he doesn’t make excuses. But we don’t just sit back and live off of what is going well. We analyze pretty much all of the mistakes. At some point, he will hear it from us – me, Dad, or his circle. He’ll definitely get video.

During every week of the season, he’s getting video from us both on things that he could’ve done better and on things that he’s doing well. We try to hold him to a high standard and hold that bar high. We don’t get content. The goal is chasing greatness. His Dad uses a term that I’ve latched onto when I talk to Steph: ‘We want this to be undeniable.’ If Steph becomes an All-Star, it’s undeniable. If he’s the best defender in the league, it’s undeniable. We want everything that he does to be undeniable. There aren’t any doubts. We make this undeniable. That is a term that we live by. His Dad rolled with that, and I love that, too.”