> ## Documentation Index > Fetch the complete documentation index at: https://docs.polymarket.us/llms.txt > Use this file to discover all available pages before exploring further. # Sports Schema > Common instrument fields for safely identifying sports markets This page documents the strongly-typed fields on the instrument that should be used to identify a sports market. **Do not parse the instrument symbol or slug** — symbol formats are not part of the public contract and may change. Always identify markets using the fields below. ## Section 1: Common Identifying Fields The following fields appear on every sports instrument. Together they uniquely describe the sport, league, event, period, market type, and handicap of a contract. ### Field Reference | Field | Location | Type | Description | | --------------------- | ---------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `event_start_time` | `metadata` | Timestamp (UTC) | Scheduled start time of the underlying event. Updated in place when a game is rescheduled. | | `event_subcategory` | `metadata` | Enum | The sport. Values: `BASKETBALL`, `FOOTBALL`, `BASEBALL`, `SOCCER`, etc. | | `outcome_type` | `metadata` | Enum | The market structure. See the enum list below. | | `market_sport_type` | `metadata` | Enum | The fully-qualified market type, including sport, participant scope, and game period. See the enum list below. | | `outcome_strike` | `metadata` | String (numeric) | The handicap or threshold for the market. Unsigned magnitude — the side the contract pays out on is encoded by `long_participant_id`. For a Cleveland +3.5 spread, this is `"3.5"`. For an over/under total of 4.5, this is `"4.5"`. Empty/`"0.0"` for moneylines. | | `long_participant_id` | `metadata` | String | Globally unique ID of the side the contract pays out on (e.g. `mlb-cle`). Only populated on individual game markets (moneylines, spreads, totals, props) — do not rely on it for futures. | ### `outcome_type` Enum The market structure of a sports instrument. | Value | Meaning | | ------------------ | ---------------------------------------------------------------------- | | `moneyline` | Win/lose market (no handicap). | | `spreads` | Point/goal/run handicap market. | | `totals` | Over/under combined-score market. | | `props` | Player or team prop. | | `futures` | Season-long or event-long futures market. | | `drawable_outcome` | Exclusive group market that admits a draw (e.g. 3-way soccer outcome). | ### `market_sport_type` Enum The period or prop variant of a sports market. Only set for sub-period markets and props. | Value | Sport | Scope | Period | Type | | ----------------------------------- | ---------- | ------ | --------------- | --------------- | | `baseball_player_home_runs` | Baseball | Player | Full game | Home runs prop | | `baseball_player_strikeouts` | Baseball | Player | Full game | Strikeouts prop | | `baseball_team_first_inning_run` | Baseball | Team | 1st inning | Run scored | | `baseball_team_first_five_winner` | Baseball | Team | First 5 innings | Moneyline | | `baseball_team_first_five_spread` | Baseball | Team | First 5 innings | Spread | | `baseball_team_first_five_total` | Baseball | Team | First 5 innings | Total | | `basketball_player_points` | Basketball | Player | Full game | Points prop | | `basketball_player_assists` | Basketball | Player | Full game | Assists prop | | `basketball_team_first_half_winner` | Basketball | Team | First half | Moneyline | | `basketball_team_first_half_spread` | Basketball | Team | First half | Spread | | `basketball_team_first_half_total` | Basketball | Team | First half | Total | The `market_sport_type` enum is the source of truth for game period and prop variants. When in doubt about which value applies to a market you're seeing, use this field rather than parsing the symbol. *** ## Section 2: Identifying Markets Use this table as a recipe book for identifying a specific market type from instrument metadata. Full-game markets are identified by `outcome_type` alone — `market_sport_type` is not set. Period markets and props always set `market_sport_type`. | To identify... | Check | | ---------------------------------------------- | ------------------------------------------------------------------------------------------ | | **Full-game moneyline** | `outcome_type = "moneyline"` | | **Full-game spread** | `outcome_type = "spreads"` | | **Full-game total** | `outcome_type = "totals"` | | **Season/event-long futures** | `outcome_type = "futures"` | | **3-way outcome** (e.g. soccer home/draw/away) | `outcome_type = "drawable_outcome"` | | **MLB first-5-innings moneyline** | `outcome_type = "moneyline"` AND `market_sport_type = "baseball_team_first_five_winner"` | | **MLB first-5-innings spread** | `outcome_type = "spreads"` AND `market_sport_type = "baseball_team_first_five_spread"` | | **MLB first-5-innings total** | `outcome_type = "totals"` AND `market_sport_type = "baseball_team_first_five_total"` | | **MLB first-inning run** | `market_sport_type = "baseball_team_first_inning_run"` | | **MLB player home runs prop** | `outcome_type = "props"` AND `market_sport_type = "baseball_player_home_runs"` | | **MLB player strikeouts prop** | `outcome_type = "props"` AND `market_sport_type = "baseball_player_strikeouts"` | | **NBA first-half moneyline** | `outcome_type = "moneyline"` AND `market_sport_type = "basketball_team_first_half_winner"` | | **NBA first-half spread** | `outcome_type = "spreads"` AND `market_sport_type = "basketball_team_first_half_spread"` | | **NBA first-half total** | `outcome_type = "totals"` AND `market_sport_type = "basketball_team_first_half_total"` | | **NBA player points prop** | `outcome_type = "props"` AND `market_sport_type = "basketball_player_points"` | | **NBA player assists prop** | `outcome_type = "props"` AND `market_sport_type = "basketball_player_assists"` | ### Worked Example: Cleveland/Detroit Over 4.5 Total A full-game total on the May 21 Cleveland Guardians vs Detroit Tigers MLB game: ```json theme={null} { "symbol": "tsc-mlb-cle-det-2026-05-21-4pt5", "metadata": { "event_id": "mlb-cle-det-2026-05-21", "event_start_time": "2026-05-21 17:10:00+00", "event_subcategory": "BASEBALL", "outcome_type": "totals", "outcome_strike": "4.5", "long_participant_id": "mlb-cle", "long_participant_name": "Cleveland Guardians", "short_participant_id": "mlb-det" } } ``` To safely interpret this contract: 1. `outcome_type = "totals"` and `market_sport_type` is unset → full-game total. 2. `event_subcategory = "BASEBALL"` → MLB game. 3. `outcome_strike = "4.5"` → over/under line is 4.5 combined runs. 4. The contract resolves "Over" if the combined score is 4.5 or more, otherwise "Under". ### Worked Example: Cleveland +3.5 Spread A full-game run-line spread on the May 20 Cleveland Guardians vs Detroit Tigers MLB game: ```json theme={null} { "symbol": "asc-mlb-cle-det-2026-05-20-pos-3pt5", "metadata": { "event_id": "mlb-cle-det-2026-05-20", "event_start_time": "2026-05-20 22:40:00+00", "event_subcategory": "BASEBALL", "outcome_type": "spreads", "outcome_strike": "3.5", "long_participant_id": "mlb-cle", "long_participant_name": "Cleveland Guardians", "short_participant_id": "mlb-det" } } ``` To safely interpret this contract: 1. `outcome_type = "spreads"` and `market_sport_type` is unset → full-game spread. 2. `long_participant_id = "mlb-cle"` → the contract pays out on Cleveland. 3. `outcome_strike = "3.5"` → handicap magnitude is 3.5 runs. 4. The contract resolves to Cleveland if Cleveland wins, or loses by fewer than 3.5 runs. *** ## Best Practices * **Never parse the symbol or slug** to determine market type, period, or handicap. Symbol formats are not part of the public contract. * **Full-game markets are identified by `outcome_type` alone.** `market_sport_type` is only set for sub-period markets and props. * **Treat `outcome_strike` as a string** in client code and convert to your numeric type. The value is unsigned — the spread direction is determined by `long_participant_id`. * **Cache and version your enum mappings.** New `market_sport_type` values are announced in the [changelog](/changelog) and rolled out in preprod before production. Subscribe to the RSS feed to be notified before new enums appear in production. * **Subscribe to instrument updates** via the streaming APIs to catch new instruments as they are listed.