The problem it solves

Every operator eventually holds the same meeting: two teams present the same metric with different values, both correct by their own definition, neither definition written down. The meeting resolves the number and not the cause, so it repeats monthly. The dictionary is the artefact that makes the cause fixable: a single place where each metric's computation is stated precisely enough that two independent analysts produce the same value.

This page describes how to build one. The reader-facing companion — what each term means and why it matters — lives in the iGaming glossary; the two layers should share names and definitions, with the dictionary as the source of truth.

Anatomy of a definition

A dictionary entry that ends arguments carries more than a formula:

FieldWhat it pins downThe dispute it prevents
FormulaNumerator and denominator, stated on named datasets"My GGR includes voided bets, yours doesn't"
GrainPer player, per brand, per market, per day — and the aggregation rule upwardAverages of averages presented as the metric
Time baseTimezone, cut-off, and whether the metric is event-time or settlement-timeThe daily number that changes depending on who runs it
Population filtersTest accounts, bots, fraud, self-excluded players — in or out, explicitlyFunnel rates that move when the exclusion list does
Restatement ruleHow late-arriving data changes a closed period, and whether history is frozen or re-stated"Last month's number changed and nobody knows why"
Owner and effective dateWho answers for the definition, since whenArchaeology instead of accountability
Known variantsThe regulatory base, the finance base, the product base — with the bridge between themThe filed number versus the board number

The metrics that earn their place first

Build outward from money and disputes, not inward from ambition. The core set for most operations:

  • The revenue bridge — turnover, GGR, NGR and every deduction between them. This is the family where two coexisting definitions cost the most; the decomposition discipline is covered in NGR drivers.
  • The acquisition funnelclick-to-registration, reg-to-deposit, FTD — where attribution windows and event definitions decide the value more than behaviour does.
  • Retention and valuecohort retention, churn, LTV — the metrics with the most silent assumptions (windows, censoring, revenue base), unpacked further in cohort analysis.
  • Payment healthapproval rate, payout timing — where the definition must name the attempt-deduplication rule or the metric is fiction.
  • Bonus economics — granted versus consumed versus cost, the distinction that bonus economics treats as the first fix.

Governance: the part that keeps it alive

Dictionaries die two deaths: they drift from the systems that compute the metrics, or they freeze while the business moves. Both are governance failures with structural fixes:

  • Definitions live next to the code that implements them — generated into the readable document, never hand-maintained in parallel. The same principle as the configuration matrix: the document is a view, not a source.
  • Changes are versioned with effective dates. A definition change is an event in the data platform's history; every chart crossing that date should be able to say so.
  • Disputes route to the dictionary, not around it. The operational habit that matters most: when two numbers disagree, the first question is "which definition", and the answer gets written back into the entry — the dispute becomes an improvement instead of a recurring meeting.
  • New metrics need a sponsor, a formula and a reason. The bar is low but real; it keeps the dictionary a contract rather than a wish list.

The test

Hand the dictionary entry and access to the warehouse to an analyst who has never computed the metric, and compare their result to production. If they match, the entry is real. If they need a conversation to match, the missing content of that conversation is exactly what belongs in the entry. Run this test on the revenue bridge first — it is the family most likely to fail it and the most expensive one to leave ambiguous.

Continue reading: The event schema — the layer every definition ultimately resolves to. The iGaming glossary — the reader-facing companion of this dictionary.