Stillwell Senior Parker Seithel Has Big Plans In Kansas For Blue Valley Tigers

Between training with Top Speed Sports Performance, hooping for St. Louis Gateway P32, and navigating college offers this summer, this high school basketball phenom wants to go higher

Playing in AAU tournaments against teams from Kansas, Missouri, Arkansas, Oklahoma, Nebraska, and Iowa, Parker's setting his sights on finishing his high school career on top. / Parker Seithel

Standing at 6’10, Parker Seithel is used to being looked up to. 

Size. Ability. Versatility. He can play inside and out and is a natural blocking presence on defense. A center who doubles as a guard. And he’s only going to get better and bigger thanks to a strategic overall game plan on how to attack his upcoming senior year in Stillwell, Kansas where he proudly reps the Blue Valley Tigers. Coming off a Junior year that saw head coach Dwight Williams’ team finish the 2025 season undefeated in district play in a historic run, Parker earned a Class 6 A Honorable Mention from the Kansas Basketball Coaches Association.

“It is an honor to be recognized for your work, however I was more proud of the results we had as a team. It does leave me a bit of wanting more as long as it translates to wins,” Parker told High School on SI.

“While we fell short of the State playoffs we accomplished more wins at Blue Valley High School than in 38 years.  We also had a 15-game winning streak before we lost to Olathe North in the last game of the season. During those 15 games, we learned how to adapt to every situation. Being up. Being down and finishing games out. We helped each other by gaining experience in what it took to win no matter the setting or the score.”

Taking Ownership Of Your Own Training Program

First things first. Put together a solid offseason blueprint through a detailed and mindful training schedule with one of the best in the Kansas City area and Midwest: Coach Joseph Potts at Top Speed Sports Performance. 

A former collegiate and professional football player, Coach Potts has trained professional athletes such as Super Bowl champions Harrison Butker, Tyreek Hill and De'Vante Bausby, NBA veteran Nick Collison, European Professional Basketball MVP Kristina Stantiago, MLB 1st round draft picks Riley Pint and Alex Lange. 

“Parker has been in our program for a bit over a year now. At our gym we individualize for each person and we let the athlete have a large portion of ownership in the direction their program goes,” said Coach Potts, who also operates as the Director of Performance for the Kansas City Current and the Strength & Conditioning Coordinator for the Fort Scott Community College Baseball program.

“We rely on them being self-aware enough to accurately rate which athletic qualities need the most focus at various times of the year and cycle the stimulus at 5-6 week intervals. With Park he's been wanting to gain size and increase his explosiveness and COD-ability. So part of the weekly routine is spent with the goal of hypertrophy while the majority is spent striving to increase power and speed.”

By training with Top Speed, Parker's vertical jump output is up 15% since joining the program to help maximize his power output on the court with St. Louis Gateway’s P32 17U. / Parker Seithel

More Bounce To The Ounce

Recently, Top Speed Sports Performance shouted out Parker for setting a personal record on his vertical reach and drawing comparisons to NBA overall draft pick by the Dallas Mavericks, Cooper Flagg. 

“He actually PR'd again yesterday. His vertical jump output is up 15% since joining the program but what's really impressive is his overall power output. He joined the program with a peak power output of 8900 watts and he's now putting out over 10,400 thanks in large part to the 20+ pounds of muscle added to his frame since joining up. Our vertical jump routine is primarily based around chronic exposure to postactivation potentiation. Essentially, we overload the body during an explosive action and then we take away the load and ask it to perform the same movement so that it can achieve output closer to its' athletic-ceiling. If you do that consistently enough with a smart load you're able to raise that ceiling - which brings the floor as well. For example, Parker is now able to jump the same height as his baseline vertical jump mark while holding 40 pounds in-hand.”

New heights. Same daily focus from Parker to rise to the occasion. 

“I feel much stronger, explosive, and more capable all the time, thanks to Top Speed’s program.  They have a proven record and they have adapted a program to help me develop my body type and needs. It’s been a pleasure working with them. It’s the place for creating elite athletes, so who wouldn’t wanna be part of that.”

Consistency and Effort. It’s the two biggest attributes Coach Potts appreciates the most about Parker and how he’s going about his work this summer. 

“A lot of guys will sign up and their bodies will write checks their hearts can't cash. Our programs are effective because they're difficult, some guys don't last a week, but Parker is probably one of our most consistent guys in terms of attendance and work ethic. As a coach that's something I majorly appreciate because those are the guys who will continue to make progress for a long time,” Coach Potts explained. 

“My area of concern is the same as it is with almost all high school athletes these days and that's the impact on their bodies from our current state of youth sports culture. Baseball, volleyball, soccer and basketball seem to be perpetually in-season these days, so you're seeing high school aged kids with significant overuse injuries that used to be more commonplace amongst the 30+ age group. So, like with them, I'd like to see him place more importance on in-season strength training and recovery to avoid those issues.”

Growth With St. Louis Gateway Knights Basketball

When Parker’s not training with Coach Potts at Top Speed, he’s standing on business with St. Louis Gateway Knights P32 17U this summer with a heavy tournament schedule in the competitive New Balance circuit. Since 1996, Gateway has been integral in AAU players reach their goals and potential.

“My game at Blue Valley is a lot different for me than at Gateway. At Blue Valley I'm one of the catalysts of the offense. I get a lot of touches on the block and opportunities to be a point forward. I have to adapt my game at Gateway because I am surrounded by more instinctual players that can create on their own. I just work hard on the boards, spread the court by pulling the opposing big out to the three point line and out run everyone. This typically puts pressure on the defense and opens up opportunities for my teammates to score. It also creates opportunities for me to score on the fast break when my defender isn’t keeping up.”

Over the past three summers, Parker has gone from being invited to the CP3 Rising Stars National Camp (twice) to playing in the Crossroads Elite Invitational, PrepHoops Top 250 Missouri and PrepHoops Top 250 Kansas events, and suiting up for Marcus Denmon Elite Basketball. Last year, he played for St. Louis Gateway’s 16U team, an experience that made him eager to get back on the court this summer with P32. 

That’s where he serves and protects on both ends of the floor. 

“I've always prided myself on my defense.  While it doesn't get a lot of stats, I alter shots, drive and force smaller players to avoid the middle.  I’m working daily to get stronger and become a more consistent scorer. I know I can shoot.  I’ve just got to be more consistent. The work will show.” 

That strong D comes in handy, especially these days when multiple offers from college programs are coming in from all directions. Luckily, Parker has some help defense behind him in Coach Potts. 

With the 2025-26 school year right around the corner, the Blue Valley Tigers have some unfinished business to attend to: winning a state title with the big man in the middle. / Parker Seithel

College Offers Come With Words Of Wisdom

His advice for student-athletes who maintain hectic schedules between training, tournaments, receiving potential offers, and juggling academics with their ever-busy social lives? 

“One, you only lose when you give up. I've seen kids cut from their high school team who went on to play in college simply because they didn't give up and continued to make strides that they were able to showcase at the club level. Two, you probably don't realize it but athletic development is just as important, if not more-so, than skill development. I've seen more scholarships awarded to kids who could run and jump better than others than I have kids who were simply really good players. You'd be surprised what two to three smart workout sessions per week can accomplish,” said Coach Potts. 

“And three, handle business in the classroom. I've lost count of how many great athletes I've seen lose their opportunity to be stars at the college level because they didn't put as much effort in the classroom as they should have. You can't be on the team if your grades can't get you into the school.”

The guidance is invaluable, priceless points Parker would be wise to take with him wherever he goes beyond Stillwell. 

“It’s a special feeling getting an offer.  A coach is inviting you into their culture,” Parker explained. 

“It’s affirmation for the hard work.  I’m more interested in developing a relationship with everyone. Relationships matter first.  I am ecstatic that so many programs appreciate my work and value my potential.” 

June’s schedule included the Midwest Showcase where Parker took to the floor against fellow high school standouts and teams from Kansas, Missouri, Arkansas, Oklahoma, Nebraska, and Iowa. Offers from Missouri S&T and Lindenwood University also arrived during the month adding to a growing list that started with his first Division I offer from Southeast Missouri State and includes the University of Central Missouri, and Pitt State University.

The college offers list isn’t the only thing getting bigger. So are the expectations Parker’s putting out into the universe knowing 2026 will be his final run as a Tiger.

“Like most teams, you want to win your conference and then adapt your goals higher,” Parker added. 

“I think we’ll be a formidable team to compete for a state championship.”