The Constraints Collective

In Part Two of this milestone two-part conversation, Ian Renshaw continues talking with Professor Chris Button (University of Otago) — this time about water safety and drowning prevention. New Zealand has one of the worst per-capita drowning rates in the world, and Chris argues the reason isn't swimming ability: it's that people learn to swim in a pool, an environment that shares almost nothing with the open water that actually threatens them.

Chris walks through a study that puts the problem in miniature — taking swimmers out in a boat on calm water and asking them to judge the distance back to shore by eye. Good swimmers judged it reasonably well; poor swimmers were badly wrong, and consistently overestimated the distance, right before being asked to swim it. His tested fix is disarmingly simple: stop teaching open-water skills in a pool, and take children to the beach, the lake, or the river instead — concentrated blocks of real-environment practice that held up on retention three months later and translated into genuine self-rescue skills.

Part Two of Two — Part One aired as Episode 100, tracing the PhD finding Chris still sees coaches average away.

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Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective).

In this month's catch-up, Ian Renshaw and Keith Davids work through a run of ideas connected by a single question: how do you prepare an athlete for the conditions, schedules, and pressure you can't control? Keith breaks down why the NBA's 82-games-in-170-days calendar has pushed coaches toward short, opponent-specific practice pockets instead of generic repetition, and Ian connects it to a piece of single-session design work he's been developing from psychology and psychiatry literature — what can actually change if you only get one go?

The conversation moves through the constraints continuum, the pair's own distinction between 'constraining to afford' and constraining to 'potentiate', and a run of stories — a Silver Ferns netball shooter whose in-house scoring system took the pressure off a stat the opposition had learned to exploit, and England's Under-21s, where a rehearsed "stay in the green" call pulled a player back from the edge of a red card. Keith closes by naming the amber zone properly — dynamical systems theory's region of metastability — and why the job isn't to coach uncertainty out of performance, but to make sure athletes have already met it once before it counts.

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If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective.

Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective).

In this landmark 100th episode, Ian Renshaw and Keith Davids are joined by Professor Chris Button from the University of Otago, whose research has ranged from ball-catching biomechanics to basketball free throws to, more recently, why so many people drown. Chris's route into research wasn't inevitable — he turned down a PhD scholarship for a job as a wine specialist before one line from Keith ("your PhD is your passport anywhere") talked him back onto the academic path.

The conversation traces the finding buried in that PhD that coaches still routinely average away: when Chris's group-level statistics on ball-catching showed no differences between participants, despite him watching them move differently in real time, the fix wasn't better instrumentation — it was refusing to average, and analysing individuals as individuals. Years later at Edinburgh, the same logic showed up in basketball free throws: novices varied early in the shot, experts showed a funnel, real variability at the start narrowing as the ball approached release. The skill wasn't the absence of variability, but the timing of when it was allowed to matter. They also dig into the interdisciplinary Manchester Metropolitan University cohort that shaped Chris's approach of arguing between frameworks rather than staying inside one — a method that carried him to Otago and, eventually, toward water safety research.

Part One of Two — Part Two continues in August's Week One Guest Podcast.

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If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective.

Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective).

An emergency episode: VAR was dominating the World Cup news cycle, and a paper had just landed asking the exact question everyone was arguing about. Ian Renshaw and Keith Davids review Schütz, Betsch & Plessner's "The Impact of Video Speed on Intention Attribution" (Psychology of Sport & Exercise, 2026) — four experiments showing that slowing footage down increases how intentional an action looks, peaking at around 1.5 seconds before easing off again.

For the first time on a theory paper episode, they bring in a guest: Scott Russell, a former referee now researching how officials incorporate social expectations into their decisions. Keith reframes the paper's cognitive explanation through an ecological lens — it's not just processing time, it's a change in the structure of information available to the viewer. Scott argues that video, even in real time, is never the event itself, just "the best artist's impression." Ian draws on his own occlusion research to show how arbitrary a single video frame really is. And the conversation lands on practical recommendations: closed, specific questions for VAR reviews, standard-speed footage as the default for disciplinary decisions, and rugby league referee Ashley Klein's decision to uphold a send-off despite video review as a model for trusting the on-field call.

A timely, sharp look at why the frozen frame keeps lying to us in the same direction, every time.

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If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective.

# From the Pitch to the Algorithm — with Ben Teune In this episode, Ian Renshaw and Keith Davids are joined by Ben Teune, Sports Scientist and Analytics Lead at the WTA (Women's Tennis Association), whose PhD work — embedded with the Western Bulldogs AFL club at Victoria University — tackles a problem every constraint-led coach runs into: you're told to "manipulate the task," but rarely given a principled way to decide what to manipulate. The conversation covers how to give representativeness a number using the specificity index and association rule mining, why looking at one constraint at a time is misleading when machine learning can surface which constraint *combinations* actually produce breakthroughs or breakdowns, and how clustering algorithms can classify drills by variability so coaches can build sessions with intentional exploration versus exploitation phases. Ben also walks through his "outnumber" research — the two distinct solutions players find when given an extra player, and how a coach can use that insight to shift team behaviour with a simple time constraint. Underpinning it all is Ian's standout line of the episode: start with the coaching problem, then find the data that answers it — not the other way around. --- If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective. Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective). 

The San Antonio Spurs led Game 4 of the 2026 NBA Finals by 29 points and lost it on a tip-in with 1.2 seconds left — the biggest comeback in Finals history. Ian Renshaw and Keith Davids use it to argue momentum isn't a mindset problem but a stable attractor state (drawing on Gernigon, Briki & Eykens' dynamical systems model of psychological momentum) that has to be deliberately broken, not willed away. They trace the same idea through hydration-break goal-scoring stats, Shane Warne's between-ball theatre, the "plus" between cricket deliveries, and a community AFL warm-up that was quietly working against its own players.

This month's free round-up pulls together June's guest episode (Michael Richardson), theory paper, and Daniel Lycett guest review. Members get the full monthly catch-up recording, early access to next month's guest conversation, and the hosts' position statement on "Constrain to Afford or Constrain to Potentiate?"

Keith and Ian go back through Daniel Lycett's PE curriculum redesign from episode 81 — and pull apart what was really going on underneath it: context, donor sports, and designing tasks people can actually succeed at. Along the way: Lego therapy for autistic learners, team chess, a French badminton study, and why Keith won't smash newer players off the pickleball court.

#95 Before the Ball Moves: How International Footballers Gain Their Advantage In this episode, Ian Renshaw and Professor Keith Davids explore the tension between practice tools and movement variability. Using Ian's experience with a golf putting mat as a springboard, they examine how template-based practice can encourage rigid repetition and ask whether this conflicts with Bernstein's principle of "repetition without repetition." The conversation covers degrees of freedom — how beginners freeze their movements and how skilled performers learn to exploit them — drawing on Ludovic Seifert's fascinating research with ice climbers and the 1964 work of AJ Templeton, who was quoting James Gibson on reading greens long before ecological dynamics had a name. --- If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective. Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective). 

#94 The Constraints Collective Podcast with Michael Richardson In this episode, Ian Renshaw and Keith Davids are joined by Professor Michael Richardson from Macquarie University, a specialist in ecological psychology and computational modelling. Mike's work sits at a fascinating intersection of mathematics, AI, and human movement — and this conversation explores what that means for how we understand and coach sport. The discussion covers how simple constraints generate extraordinary complexity in sport (just as adding lines and rules to an open field creates beautiful, emergent games), and how Mike's lab is using neural networks to predict player decisions up to two seconds before they happen. They unpack the concept of "addressing the performance environment" — the often-invisible skill of how athletes position their bodies, vision, and attention to access the information they need — and why this subtle layer of preparation underlies almost every spectacular action we see in sport. The conversation also touches on explainable AI, recurrence analysis, and what multi-agent coordination patterns in team sports and even video gaming reveal about collective decision-making. A wide-ranging and thought-provoking episode for anyone interested in the science behind performance. --- If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective. Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective). 

# Round Up 10 — May 2026 In this month's update, Ian Renshaw and Professor Keith Davids catch up on the latest from the Constraints Collective world before diving into a rich discussion on skill adaptation, movement variability, and the dangers of template-based practice. Using Ian's experience with a golf putting mat as a springboard, they explore Bernstein's principle of "repetition without repetition" and ask whether tools that prescribe exact movement patterns work against the kind of functional variability that underpins real skill development. The conversation moves into degrees of freedom — how beginners freeze their movements and how skilled performers learn to exploit them — drawing on Ludovic Seifert's fascinating research with ice climbers and the 1964 work of AJ Templeton, who was quoting James Gibson on reading greens long before ecological dynamics had a name. They also celebrate the release of the Palgrave Handbook of Creativity in Sport, which features multiple contributions from the TCC community, and share updates on a skill adaptability series that's rapidly gathering momentum. --- If you're getting value from our podcast check out our membership options and coaching community at [www.theconstraintscollective.com](https://www.theconstraintscollective.com) where you can access podcast summaries, narrated presentations, early release podcasts and monthly online meet ups with experts from the Constraints Collective. Support the running of the podcast at [patreon.com/TheConstraintsCollective](https://patreon.com/TheConstraintsCollective).