Bringing AI to Tennis with Apeak ft. Brian Park

Summary

Brian Park, South Korean-born tennis player turned sports psychology consultant and co-founder of the AI-powered mental training app Apeak, describes the architecture and philosophy of a platform he built to democratize personalized mental skills training for tennis players at any level. The app’s core innovation: rather than a static content library (the model used by all existing mental training apps at the time), Apeak is a dynamic, input-output system that learns from each user’s daily reflection data and uses AI to recommend progressively relevant training content. The workflow — pre-session visualization, then post-session reflection entered by the player in text, then AI-generated recommendations for the next session’s focus — creates a feedback loop that Park compares to having a sports psychologist who knows what happened in your most recent practice. Beta testers in California showed UTR improvements of 0.5-0.6 over the testing period. Ambassadors include Peter Smith (USPTA), Dave Porter, Marcos Andraska, and Jonathan Stark (former ATP #1 in doubles, top 30 in singles).

Guest Background

Brian Park grew up in South Korea, was identified as a talented junior player, and was sent to Australia at age 16 for two years of high-level junior training (including ITF futures competition). He was introduced to mental skills training in Australia through a book called “Mental Toughness” by Jim Loehr (“the founder and the guard of sports psych”) — Park credits Loehr’s work as transforming his game and eventually his career direction. After his family experienced financial hardship, Park gave up the professional pursuit, obtained a tennis scholarship to play college tennis in the US, earned both a bachelor’s and a master’s degree in sports psychology, and spent 20 years in the US working as a sports psychology performance consultant with players ranging from top 300 ATP to 11-year-old juniors (at rates of $200 per session, typically two sessions per month). He founded Apeak after becoming frustrated with the static, content-only nature of all existing mental training apps and recognizing that the technology infrastructure existed to build something genuinely personalized and adaptive.

Key Findings

1. The Static App Problem: Why Existing Mental Training Tools Don’t Work

Park’s founding insight: “there’s so much technology available these days but yet there’s nothing — no advanced technology available for mental training apps — and everything’s so static meaning that every app out there is just a host of content and you just go in and listen to whatever you want. There’s no monitoring, there’s no personalization, there’s no AI, there’s no algorithm, everything’s just static.” The failure mode of static mental training apps: they provide the same content regardless of what happened in the player’s last practice or match, offer no mechanism for players to reflect on their mental performance, and cannot adapt to the specific challenges a player is currently facing. Park’s equivalent: a sports psychologist who never asks you questions and just reads you the same scripts every session regardless of how you’re doing.

2. The Core Input-Output Loop

The Apeak workflow has four stages: (1) Assessment at signup creates an initial personalized training plan organized around specific mental skills in a prescribed order; (2) Pre-session visualization delivers a 4-6 minute guided audio experience that primes the player for the specific skill they’re working on (reading the opponent, serving on big points, etc.) before they step on the court; (3) Play/practice — the player competes; (4) Post-session reflection — the player returns to the app and enters text describing what happened, specifically what they can improve. The AI then reads the text and recommends the next visualization from the content library most relevant to what the player described. This creates personalization from the player’s own language rather than from external assessment — the system learns what the player needs from what the player says about themselves.

3. Visualization as Professional Practice, Not Junior Development Gimmick

Park demonstrates the scientific and professional credibility of visualization by referencing Bianca Andreescu’s and Novak Djokovic’s publicly described visualization practices. Andreescu attributes her US Open victory in part to daily visualization training she began as a young player. Djokovic describes visualizing every match before he plays. Park’s point: “there’s a lot of professional athletes they do — some of them publicly say it and some of them don’t say it publicly but a lot of them do it.” The app’s content library is organized to normalize visualization as a pre-competitive ritual — accessed in the 30-60 minutes before competition or first thing in the morning depending on the player’s preference.

4. Reflection as the Speed-of-Learning Multiplier

Park cites research establishing that reflection increases the speed of learning — “when you reflect on yourself you learn things much faster and there are so many researches that shows that.” The post-session reflection component of Apeak is structured around two questions: “What went well, and why?” (to build awareness of what to repeat) and “What can you improve?” (to generate the specific input for AI recommendation). The structure enforces a growth mindset framing: even after losses, the player is prompted to identify what worked before addressing what didn’t. Park describes the post-session reflection as the “sweet spot” and “special sauce” of the app — the feature that differentiates it from all competitors.

5. AI Text Analysis as the Personalization Engine

When a player types in their post-session reflection, Apeak’s AI reads the text and recommends the most relevant next visualization or resource from the content library. Park demonstrates this live: Lisa Stone types “I didn’t hit my spots on my serve on the big points” and the AI recommends a serve-placement visualization. The recommendation logic is explicit but evolving — at the time of recording, the AI was still building its training dataset and offering 6 candidate recommendations rather than a single definitive one, with user feedback on which recommendations were most helpful feeding back into the model. The longer-term vision: as the dataset grows, recommendation precision improves, and the system becomes capable of generating on-demand content to address gaps it identifies.

6. Affordability as a Core Mission

Park frames affordability explicitly: “a lot of the sports psychologists including myself — I was charging $200 for one 45-minute consultation session and a lot of the players were spending two sessions per month — I mean that’s $400-500 a month. I wanted to create something that is affordable and provide really high quality.” The professional-level sports psychology access that Apeak provides is currently available only to players whose families can afford $400-500/month — a significant barrier for the mid-tier junior and developing professional players who most need mental skills support and are least able to pay private practitioner rates. The app creates a scalable, lower-cost alternative while maintaining the personalization that static content platforms cannot provide.

7. Beta Testing Results: 0.5-0.6 UTR Improvement

Park reports beta testing results that show California players using the app improved their UTR by approximately 0.5-0.6 during the testing period. Park acknowledges that some beta testers in regions with limited match play (like Seattle during COVID restrictions) showed no improvement, not because the app didn’t work but because they hadn’t been able to play matches to convert mental skill gains into ranking improvement. The UTR improvement metric is a practical, observable outcome measure for a mental skills intervention — rare in sports psychology, where interventions are often evaluated through subjective self-report.

8. Expert Ambassador Network as Content Validation

Apeak’s ambassador and contributor network at the time of recording included: Peter Smith (USPTA), Dave Porter (former coach, described as a “great patent”), Marcos Andraska (described as Dave Porter’s good captain, ranked ATP 27 in the world), and Jonathan Stark (ATP #1 in doubles, top 30 in singles). Park describes this network as both validators of the app’s credibility and future content contributors — each ambassador is expected to provide perspective from their specific expertise (player development, professional coaching, high-performance mental skills). The multiple-perspective content strategy prevents the app from becoming “just Brian Park’s philosophy” and creates a more comprehensive mental skills ecosystem.

Actionable Advice for Families

• Junior players should establish a pre-match visualization routine before the competition season begins — even without an app, spending 10-15 minutes before a match mentally rehearsing key tactical decisions (where to serve, when to approach the net, how to handle break point pressure) develops the same mental circuitry that Andreescu and Djokovic describe as central to their competitive preparation
• Players who work with sports psychologists should ask for written post-session reflection prompts to complete after each practice — the act of writing (not just thinking) about what went well and what can improve accelerates the learning cycle, as the research Park cites establishes
• Families evaluating mental skills investments should recognize that $200/session sports psychology rates are not the only access point — technology-based tools at a fraction of the cost can provide meaningful mental training, particularly for players who need consistent daily practice rather than occasional professional consultation

INTENNSE Relevance

• Mental skills as a league infrastructure investment: INTENNSE’s one-serve format and rally-scoring structure create specific psychological pressure points (every service game is higher stakes, every point counts immediately) that standard ATP/WTA mental skills programs don’t specifically address. A league partnership with Apeak — co-developing INTENNSE-specific visualization content for rally scoring, one serve, and team tennis pressure — would be a differentiating player development asset
• AI-personalized player development at scale: Park’s architecture — AI that learns from individual player reflection text and recommends personalized training — is the template for how INTENNSE could deliver personalized coaching at scale across a 10-team league without requiring individual sports psychologist sessions for every player. A mental skills platform that learns from league-specific match data and player reflection would compound in value as the league accumulates seasons of data
• Broadcast mental skills narrative: Apeak’s visualization and reflection framework creates broadcast narrative opportunities — players who describe their pre-match mental preparation in interviews, coaches who discuss the mental skill they worked on in mic’d coaching moments, data on which mental focus points correlate with better match performance. Mental skills are currently invisible in tennis broadcast; Apeak’s framework makes them tangible and discussable
• UTR improvement as a measurable outcome: The 0.5-0.6 UTR improvement Park reports from beta testers is the kind of evidence-based outcome measurement INTENNSE needs for player development programs. A league that can demonstrate measurable performance improvement from its player development infrastructure creates a competitive advantage in player recruitment and retention
• Affordability as a pathway narrative: Park’s mission to democratize professional-grade mental skills training — “I wanted to create something that is affordable and provide really high quality” — maps onto INTENNSE’s core league narrative: professional-quality resources should not be available only to the wealthiest players. A league that provides every player with access to mental skills tools that were previously available only to top-50 ATP players makes a tangible argument for the INTENNSE value proposition

Notable Quotes

“There’s so much technology available these days but yet there’s nothing — no advanced technology available for mental training apps — and everything’s so static meaning that every app out there is just a host of content and you just go in and listen to whatever you want.”

“A lot of the sports psychologists including myself — I was charging $200 for one 45-minute consultation session and I wanted to create something that is affordable and provide really high quality.”

“Very often a close match is determined by the small decisions you make on critical points — it could be where you decided to serve, how aggressive or passive you decided to play on a key point.”

“When you reflect on yourself you learn things much faster — and there are so many researches that shows that.”

“I quit my job because I believe in it so much — I went all in on this project.”

“A lot of the beta testers from California that have been using it — they have everyone of them have benefited tremendously, with UTR improvements of 0.5 to 0.6.”