Dossier 02 / Models

How a Model Finds Patterns

A model can reproduce a history of selection very efficiently. That does not mean it has discovered an independent measure of potential.

Read the target before reading the ranking.

The target is a decision in disguise

A supervised model learns relationships between recorded inputs and a chosen outcome. In scouting, that outcome might be a later contract, minutes played at a specified level or improvement in a repeatable test. None is a universal definition of talent. Contracts reflect organisational priorities; playing time reflects coaching decisions; test improvement captures only part of sporting development.

If historical selection becomes the label, the model may learn whom an organisation previously preferred. That can be useful for examining institutional habits, but it is not proof of unrealised potential. Write down the outcome, observation window and population in ordinary language before discussing algorithms.

A defensible discovery target is usually modest and actionable. It might support inviting an athlete for a further role-specific assessment. It should not claim to determine a person’s eventual career from a narrow slice of performance.

Inputs carry assumptions

Assumption

More features always reveal more about ability.

Observation

Additional inputs can introduce leakage, noise, privacy risk and proxies for unequal access.

Features are the values a model receives: event counts, running measures, video-derived positions or summaries of observed decisions. Transforming them can improve comparability, but each transformation requires a reason. Rates per minute can help with unequal playing time while becoming unstable for athletes with very few minutes.

Data leakage occurs when information unavailable at the intended decision time enters training or evaluation. A later contract status hidden inside a scouting category can make a model appear remarkably accurate. Randomly splitting repeated records from the same athlete can create a subtler version: the system recognises the person instead of generalising to an unfamiliar athlete.

Commercial tools from Catapult, Hudl and Stats Perform operate in different parts of sports data and analysis. Their existence does not establish that a particular derived feature predicts potential. Evaluate the actual collection process, permitted use and intended decision rather than treating a supplier’s name as evidence.

Different methods answer different questions

A simple statistical baseline can show whether complex modelling adds useful information. Logistic regression may estimate a defined binary outcome. Tree-based methods can capture nonlinear relationships. Clustering groups similar profiles without requiring an outcome label. Computer vision can help extract movements from footage, but extraction errors remain part of the evidence chain.

Similarity search is often attractive for discovery: find performances resembling a desired role profile. Yet resemblance to a successful group does not establish the same future outcome. Athletes can succeed through different combinations of strengths, and historical examples may cover only a narrow range of backgrounds.

The scikit-learn documentation explains the separation of fitting, validation and testing. XGBoost documents one widely used family of gradient-boosted models. These are methodological resources, not scouting authorities. A transparent baseline with better coverage may serve a programme more responsibly than a powerful model trained on an unrepresentative archive.

An adult analyst comparing handwritten observations with training footage on a screen

Compare against a real alternative

Ask whether the system improves a clear observation process, not merely whether it beats an artificial benchmark.

A score is not a promise

A ranking gives an ordering; a probability estimates an outcome under specified conditions. They are not interchangeable. A score of 80 on an internal scale does not automatically mean an 80% chance of success. Even a probability needs calibration checks: among comparable cases receiving similar estimates, how often did the defined outcome occur?

Uncertainty has several sources. The dataset may be small, measurements may be noisy, and the future environment may differ from the training environment. An athlete outside the training distribution deserves an explicit warning rather than an apparently precise score. Where appropriate, the system should abstain and request further evidence.

Test ranking stability across reasonable modelling choices and repeated samples. If small changes repeatedly reorder nearby athletes, display that instability. A broad review group can be more honest than a tightly numbered list. Confidence intervals or other uncertainty summaries should be described with their assumptions, not presented as guarantees.

Explain the output without inventing a cause

Feature-attribution methods can indicate which inputs influenced a particular output. They do not prove that changing one input would cause an athlete’s future to improve. Correlated inputs complicate interpretation, and an explanation can look plausible even when the model relies on the wrong relationship.

Ask for a short model record: intended use, training population, target, exclusions, validation design, known weaknesses and review triggers. The NIST AI Risk Management Framework provides a broader structure for thinking about validity, transparency and accountability. It is a useful governance reference, not a certification that a sporting model is safe.

The final test is whether the output supports a better next question. “Observe this athlete against stronger opposition because the current evidence is limited” is a usable recommendation. “This athlete lacks potential” closes inquiry more firmly than the evidence usually permits.

Reference starting points

Challenge the shortlist