How Rugby Sentinel knows anything.

Every metric is a dated observation with unit, geography, source, method, coverage and confidence.

• Never display fabricated live participation, injury, financial or audience data.

Seasonal sporting usages/visits, event participations, unique registered players and spectator attendance are different units.

• Never convert Turf City usages into unique rugby players.

Closing active player stock = opening stock + new entrants + returning players + inbound transfers − dropouts − outbound transfers.

P_close = P_open + E + R + Tin − D − Tout

• Do not compute a national balance until a source with unique-player coverage exists.

Produced, retained, exported, representing another nation, inbound, returning, retired, pathway conversion.

• Do not moralise movement. Observe the system.

Standalone Team Ratio, Composite Dependency, Age-Grade Continuity — calculated only where team lists exist.

Standalone Team Ratio = standalone teams / total teams

• Do not infer club health from a single merged team.

Dimensions: governance integration, shared identity, shared facilities, junior-to-senior conversion, senior involvement in junior rugby, pathway visibility, volunteer return, alumni connection.

• Do not fabricate an index value.

Registration, levy, club fee, uniform, insurance, equipment, travel, representative fees, subsidies.

• Do not prejudge whether a system invests in or extracts from juniors.

Infrastructure loading, utilisation intensity, junior carrying capacity, facility stress, capital gap, capital productivity, regeneration leverage.

• Tenure is part of infrastructure. Capital without tenure is not treated as equivalent capacity.

Did the pulse merely occur, or did it replenish the reserve?

• A World Cup is not automatically regeneration.

Constraint and decline dimensions. Shown as components, never as one opaque number.

• Do not collapse need, potential and bankability.

How strongly might an intervention change the trajectory?

• Potential is not a funding recommendation.

Land, tenure, planning, governance, revenue, maintenance, co-funding, procurement.

• This is not an investment offer or financial advice.

Default unit is suspected or confirmed concussion per 1,000 player-hours, not raw counts.

• Information is not medical advice.
• Population rates do not determine individual risk.
• Association is not causation.

Age, height, weight, maturation, position and exposure — aggregated and de-identified only.

• No public record of a named child’s height, weight or concussion history.