Returns, per ranking system, the newest record effective ON OR BEFORE as_of — never one dated after it. Every other ranking field in this API is the player's CURRENT value joined at read time, so replaying an old match elsewhere shows today's ranks; this endpoint is the point-in-time answer. Systems are never collapsed into a single "rank": ATP/WTA and the ITF circuits carry rank+points, UTR carries a rating with null rank and points because it has neither. meta.coverage.oldest_available gives the earliest date each system can answer for — ITF and UTR observations reach back to 2026-06-01 (append-only per-player history accumulates from 2026-07-29) and nothing earlier can be reconstructed.

TWO MODES — with player ids (ULTRA) — the per-player point-in-time records described above. WITHOUT player (PRO) — the FULL published table in rank order for exactly one system, the newest week at or before as_of; rows carry player_name as published and a null player_id for players outside our roster, so the table has no silent holes. utr has no listing (a rating, not a ranking).

SYSTEM=UTR — observed ratings, honestly bounded. UTR records are observed from UTR's public search: a rating UTR withholds appears as ABSENT, never as 0, and rating is the only populated value — rank and points are always null. Per-player as-of ONLY — there is deliberately no UTR listing, because a table of only the players we happen to track would be a fake leaderboard. Per-player history accumulates from 2026-07-29; scattered earlier single-snapshot observations reach back to 2026-06-01. Coverage is a deliberate bias, not a roster mirror: the 24-hour sweep targets players with no official rank and no Elo rating (so it skews ITF), and among players active in the last 60 days it holds 931 of 5,606 ITF players (16.6%), 197 of 1,903 Challenger (10.4%), 43 of 573 WTA (7.5%) and 15 of 525 ATP (2.9%) — measured 2026-08-17.

SYSTEM=ELO — THE AS-OF ELO TAPE (ULTRA in BOTH modes). Our own computed Elo for 65,622 players on four independent ladders (overall, hard, clay, grass), back to 1877 (ATP) and 1968 (WTA), covering the main tours plus challengers plus the futures tier. It answers what a player was rated BEFORE a given match, which is the only shape a backtest can consume. It is a HISTORICAL TAPE rather than a live leaderboard — the corpus behind it is fixed and no longer receives new results, so meta.coverage.newest_available states the tape's head date on every response (2026-06-15 at publication), and you should read it before treating the table as current. A week's results become effective 14 days after that week begins — strictly after the longest event in tennis — so the failure direction is staleness, never look-ahead. rating is the Elo. rank is LISTING MODE ONLY and is null in per-player mode, because an Elo has no global rank at a past instant until you say which field and which activity window you mean. points is always null. matches is the count on THAT ladder, published so that a rating still near its 1500 cold start is visible rather than inferred. A ladder a player has never played is omitted, never substituted. Ratings are on our own scale, are not comparable with Elo published elsewhere, and do not decay — a surface played only a few weeks a year (grass in particular) moves slowly, so a rising player can sit below an established one for several seasons while beating them. A CURRENT per-player Elo remains free on GET /players/{id}; this is the point-in-time series, the leaderboard and the bulk export. That free rating is sourced differently and sits on a DIFFERENT scale — the two differ by roughly 150 Elo of per-player standard deviation — so never present a rating from one scale against a rating from the other. The Elo listing REQUIRES tour — the ATP and WTA walks are disjoint, so a combined leaderboard would not be comparable — and takes exactly one surface (default overall). elo is never implicit — omitting system returns the official systems only.