Abstract editorial composition of Rule 12, Association is not causality, with a twenty-point path and the current stage illuminated in gold.
20 Rules of High Performance · 12/20

Rule 12

Association is not causation

Availability and victory go hand in hand in studies, but better teams can also create environments that protect athletes.

Editorial series · Rule 12 of 20Availability, return and sustainable performance

The data shows that availability and success go hand in hand. He doesn't say, alone, who pulled who.

An analyst and coach compare trends on monitors beside the training field.
Visual 01 · Ultra-photorealistic editorial sceneRule 12: Association is not causation

Association begins the investigation; mechanism and confounders support the inference.

Composite scene · illustrative example

The table seemed to explain everything

At the end of the championship, two columns stood out. Teams with greater availability appeared near the top; those most affected by injuries sat lower. The story seemed complete: keeping players healthy made teams win.

Then the analysis moved closer. The clubs at the top also had deeper squads, larger structures, greater technical quality, and financial advantages. Some controlled more possession and may have been exposed differently. Others won more and could therefore manage minutes earlier.

The association remained relevant. It had only lost its false simplicity. Perhaps availability supported results; perhaps results also helped preserve availability; both probably responded to shared processes.

Instead of discarding the data, the team turned it into questions: what mechanism would be plausible? What could be measured across the season? Which change would produce an observable response without promising causality too soon?

From the moment to the criterionA strong association deserves attention. What it does not deserve is to be promoted to a cause simply because it fits inside a convincing sentence.

Teams with a lower injury burden can win more because they keep key players available. They can also have more resources, deeper rosters, better communication and planning — factors that simultaneously favor health and results.

There is also the opposite direction: teams that control matches may face different exposures; clubs that advance in competitions play more; Bad results can increase pressure, change and risky decisions. Reality produces cycles, not simple arrows.

Decision blueprint for Rule 12: Association is not causation.
Visual 02 · Decision blueprintRule 12: Association is not causation

When two variables go together, the decision begins — not ends — with discovering the mechanism and confounders.

What an observational study allows us to conclude

When researchers follow teams without experimentally controlling all decisions, they observe real-world relationships. This design is valuable and is often the only one ethically possible. It identifies patterns, estimates magnitude and generates hypotheses.

But unmeasured variables may explain part of the result. Even statistical adjustments do not eliminate all confounding. Saying that a lower injury burden was associated with more points is accurate. Saying that each injury avoided will cause a certain number of victories goes beyond the drawing.

Proportional language protects the decision from two errors: ignoring a consistent signal because there is no perfect test or selling certainty that the data do not provide.

Decision flow for Rule 12: Association is not causation.
Visual 03 · Decision flowRule 12: Association is not causation

The data shows that availability and success go hand in hand. He doesn't say, alone, who pulled who.

Visual continuum for Rule 12: Association is not causation.
Visual 04 · Rule continuumRule 12: Association is not causation

The interpretation is stronger when there is temporality, consistency between contexts, dose–response relationship, plausible mechanism and reduction in outcome after an adequate intervention. No single criterion resolves causality, but the set increases confidence.

Causality requires a plausible and testable chain

The interpretation is stronger when there is temporality, consistency between contexts, dose–response relationship, plausible mechanism and reduction in outcome after an adequate intervention. No single criterion resolves causality, but the set increases confidence.

In the case of availability, the proposed chain may include more training continuity, more selection options and less compensatory overhead. Each link needs its own evidence. If the organization only measures the beginning and end, it does not know where to act.

This caution also applies to load and injury. Associations between load increases and events do not authorize a universal individual risk formula. Metrics can describe exposure without accurately predicting who will be injured.

Conceptual curve for Rule 12: Association is not causation.
Visual 05 · Conceptual curveRule 12: Association is not causation

Explanatory visual — not real data.

Visual state comparison for Rule 12: Association is not causation.
Visual 06 · State comparisonRule 12: Association is not causation

Causality requires a plausible and testable chain

Good practice uses association as a signal, not a verdict

If multiple sources point out that greater availability accompanies better results, it makes sense to invest in prevention, rehabilitation and team processes. The investment, however, must be evaluated by the mechanisms it intends to modify.

The question is no longer “did the study prove it?” and becomes “which decision is justifiable given the expected effect, cost, risk and uncertainty?”.

Capacity × demand matrix for Rule 12: Association is not causation.
Visual 07 · Capacity × demand matrixRule 12: Association is not causation

When two variables go together, the decision begins — not ends — with discovering the mechanism and confounders.

Reading rule

Association describes statistical co-occurrence. Causality requires evaluating direction, confounders, mechanism, temporality, and effect of interventions.

Before turning data into action

  • Name the study design and use compatible verbs: associated, predicted, reduced, or caused.
  • List alternative explanations and factors that may affect exposure and outcome.
  • Define which link in the mechanism your intervention intends to change and how it will be monitored.
Criteria checklist for Rule 12: Association is not causation.
Visual 08 · Applied criteriaRule 12: Association is not causation

Before turning data into action

Rigor does not weaken the message. It prevents useful evidence from being destroyed by a promise greater than it can support.

In high performance, the most valuable data is not what ends the conversation. That's what improves the next question.

A strong association deserves attention. It still doesn't deserve a made-up causal story.
Scientific basis

Verified references

4 sources
  1. Hägglund M, Waldén M, Magnusson H, et al. · 2013Injuries affect team performance negatively in professional football: an 11-year follow-up of the UEFA Champions League injury studyBritish Journal of Sports Medicine. 47(12):738–742. DOI: 10.1136/bjsports-2013-092215.
  2. Drew MK, Raysmith BP, Charlton PC · 2017Injuries impair the chance of successful performance by sportspeople: a systematic reviewBritish Journal of Sports Medicine. 51(16):1209–1214. DOI: 10.1136/bjsports-2016-096731.
  3. Impellizzeri FM, Tenan MS, Kempton T, Novak A, Coutts AJ · 2020Acute:Chronic Workload Ratio: Conceptual Issues and Fundamental PitfallsInternational Journal of Sports Physiology and Performance. 15(6):907–913. DOI: 10.1123/ijspp.2019-0864.
  4. Bahr R · 2016Why screening tests to predict injury do not work—and probably never will…: a critical reviewBritish Journal of Sports Medicine. 50(13):776–780. DOI: 10.1136/bjsports-2016-096256.
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20 Rules of High Performance · 12/20

A strong association deserves attention. It still doesn't deserve a made-up causal story.

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