The Grappling Index rates every professional grappler from verified match results — no panels, no politics, no favors. The exact coefficients are proprietary; the principles are not:
Opponent strength drives everything. Beating a top-rated athlete moves your rating far more than beating an unrated one. Padding a record does nothing here.
How you win matters. A submission moves the needle more than a points win; a points win more than a referee decision.
Ratings admit what they don't know. Every rating carries an uncertainty band (±). Few matches or a long layoff widen it; the band tightens as evidence accumulates.
Inactivity doesn't erase greatness — it raises doubt. Athletes keep their rating while inactive, but leave the active ladder after 18 months without a match. Peak ratings are preserved on the all-time list.
Gi and no-gi are separate sports here. Each has its own ladder; nothing is averaged. The Overall rating is a third, independent rating computed across every professional match in both rulesets — the answer to "best grappler, period."
Format context matters. Winner-stays-on team formats (e.g. Quintet-style) structurally pit tired athletes against fresh ones, so those results carry reduced weight in both directions — the ratings learn from them, cautiously.
Only professional adult matches score. ADCC and its trials, IBJJF adult black belt, WNO, PGF, Polaris, UFC BJJ, EBI and peers. No youth, masters, amateur or exhibition results — and no Combat Jiu Jitsu, which the Index treats as a different sport.
Unverified rulesets don't score. Promotions that run both gi and no-gi under one banner (e.g. Fight to Win) only count toward a ladder when the specific match's ruleset is verified.
Corrections: every match in the database carries its source. If a result is wrong, it gets fixed and every affected rating recomputes.