Skip to content
oanor
Sign up free
Marketplace Pricing Features Sign in
GET /v1/expected-value

Expected value of a stake

Try it live

10 free calls per day — no sign-up, no API key. Goes through the oanor gateway.

Custom headers (optional)
api.oanor.com/roulette-api

It works. Grab an API key and use it in your project.

Get an API key

Code snippets

curl "https://api.oanor.com/roulette-api/v1/expected-value" \
  -H "x-oanor-key: oanor_test_..."
await fetch("https://api.oanor.com/roulette-api/v1/expected-value", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
$ch = curl_init("https://api.oanor.com/roulette-api/v1/expected-value");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);
import requests
requests.get(
    "https://api.oanor.com/roulette-api/v1/expected-value",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "note": "Expected value = stake × (win probability × (payout + 1) − 1) — always negative, equal to minus the stake times the house edge (about 2.7 % European, 5.26 % American) no matter the bet. Over many spins you lose that fraction of everything you wager; no betting pattern changes it.",
        "inputs": {
            "stake": 10,
            "wheel": "european",
            "bet_type": "straight"
        },
        "expected_loss": 0.2703,
        "payout_on_win": 350,
        "expected_value": -0.2703,
        "win_probability_pct": 2.7
    },
    "meta": {
        "timestamp": "2026-06-06T15:30:39.373Z",
        "request_id": "43894bd8-004b-4a95-9b83-215b2e348653"
    },
    "status": "ok",
    "message": "Expected value",
    "success": true
}