Odds API by market / MLB

MLB Walks API

Live batter_walks odds across every book that posts it, in one REST call — and, unlike any other odds API, every one of those outcomes settled against the official result once play ends.

No credit card. 1,000 requests / day on the free tier.

What MLB walks is

Bases on balls drawn by one hitter.

How we settle it. Graded against the batting stat group's walks column.

6
books quoting it on the next event
8/12
of the next MLB events carry it right now
10,809
outcomes settled in the last 4 days

Every number on this page is measured against the live API, never copied from a spec sheet. Last measured 16 August 2026.

Books posting MLB walks

Measured live, not listed from a spec. Coverage moves — a book that has not put its board up yet will not appear until it does, which is exactly what this list is for.

Betr PicksDabbleDraftKingsPrizePicksSleeperUnderdog Fantasy

Line shopping across all of them is one request — every book arrives in the same bookmakers array, not one call per book. Add ?bookmakers= to narrow it, or use /best-line for the best price per line already ranked.

Recently settled MLB walks outcomes

These are real rows out of the API, not an illustration. Each one was a price on a board before the event and carries the actual figure it was graded against afterwards. No other odds API returns that last column — they stop at the price.

10,809 walks outcomes settled in the last 4 days across 7 books. The 12 most recent:

PlayerBetActualResult
Denzer GuzmanOver 0.50.0lost
Jose SiriOver 0.50.0lost
Mike TroutOver 0.50.0lost
Mike TroutOver 0.50.0lost
Denzer GuzmanOver 0.50.0lost
Jose SiriOver 0.50.0lost
Nolan SchanuelOver 0.5void
Nolan SchanuelUnder 0.5void
Moises Ballesteros1+ Walksvoid
Oswald Peraza1+ Walks1.0won
Tyler Heineman1+ Walksvoid
Oswald PerazaOver 0.51.0won

Over/Under split, last 4 days

The Over won 30.6% of 4304 decided walks lines (1315 over, 2989 under). Computed from the settled rows themselves, scoped to MLB only.

Read off 4,611 Over legs out of 10,809 settled outcomes on this market. The rest are Unders and milestone legs (“1+”, “2+”) that some books price here too, and a threshold rung is not an Over.

A few days of one market describes a few days — it is not an edge. Pull the full history through /exports/resolved-props for a sample worth modelling on.

Live response

Captured from the real endpoint on Boston Red Sox @ Pittsburgh Pirates, trimmed to one book and three outcomes so the shape stays readable. The full response carries every book and every line, alternates included, in the same call.

{
  "id": "138811",
  "sport_key": "baseball_mlb",
  "home_team": "Pittsburgh Pirates",
  "away_team": "Boston Red Sox",
  "commence_time": "2026-08-16T17:35:00Z",
  "live": true,
  "last_update": "2026-08-16T22:44:42.595376Z",
  "bookmakers": [
    {
      "key": "betr",
      "title": "Betr Picks",
      "last_update": "2026-08-16T17:36:20.351547Z",
      "link": null,
      "book_event_id": null,
      "markets": [
        {
          "key": "batter_walks",
          "last_update": "2026-08-16T17:36:20.351547Z",
          "period": null,
          "suspended_at": null,
          "outcomes": [
            {
              "name": "Over",
              "description": "Esmerlyn Valdez",
              "price": 100,
              "point": 0.5,
              "book_updated_at": null,
              "book_version": null,
              "payout_multiplier": null,
              "dfs_odds_type": "regular",
              "last_change_at": "2026-08-16T02:44:55.552372Z",
              "line_gap": null,
              "book_outcome_id": null
            },
            {
              "name": "Over",
              "description": "Nick Sogard",
              "price": 100,
              "point": 0.5,
              "book_updated_at": null,
              "book_version": null,
              "payout_multiplier": null,
              "dfs_odds_type": "regular",
              "last_change_at": "2026-08-16T02:44:55.552372Z",
              "line_gap": null,
              "book_outcome_id": null
            },
            {
              "name": "Under",
              "description": "Esmerlyn Valdez",
              "price": 100,
              "point": 0.5,
              "book_updated_at": null,
              "book_version": null,
              "payout_multiplier": null,
              "dfs_odds_type": "regular",
              "last_change_at": "2026-08-16T02:44:55.552372Z",
              "line_gap": null,
              "book_outcome_id": null
            }
          ]
        }
      ]
    }
  ]
}

The response shape is the-odds-api compatible — events, bookmakers, markets, outcomes — so migrating is usually a base URL change.

Try it

1. List MLB events to get an event id:

curl "https://api.prop-line.com/v1/sports/baseball_mlb/events?apiKey=YOUR_API_KEY"

2. Pull walks for one game across every book — this exact URL works right now:

curl "https://api.prop-line.com/v1/sports/baseball_mlb/events/138811/odds?apiKey=YOUR_API_KEY&markets=batter_walks"

3. After the game, get the graded outcomes with the actual stat:

curl "https://api.prop-line.com/v1/sports/baseball_mlb/events/138811/results?apiKey=YOUR_API_KEY"

Steps 1 and 2 run on the free tier. Step 3 — prop resolution — starts on Hobby at $9/mo. See pricing.

Get your free MLB odds API key

1,000 requests / day. No credit card. The same key covers every sport and every market — not just this one.

Free tier includes 1,000 requests/day. Upgrade anytime.