# Round robin calculator

A round robin calculator creates every fixed-size parlay from your selections. The number of bets is the combination count, and total stake is that count times the stake per parlay. The displayed maximum return adds each combination’s payout when every selection wins. Partial wins pay only the combinations whose selections all win.

Canonical page: https://getoddsapi.com/round-robin-calculator

## Free API key

Get a free GetOdds API key: **1,000 requests per UTC day and 60 per minute, no card**. One key covers REST and the hosted MCP server.

Sign up: https://getoddsapi.com/sign-up?ref=ai-claudebot

## Quickstart

1. Create an account at https://getoddsapi.com/sign-up?ref=ai-claudebot, open https://getoddsapi.com/dashboard and issue a key with the sources you need (draftkings, fanduel, betrivers, prizepicks or underdog). Keep it in a server environment variable named GETODDS_API_KEY.
2. Read current DraftKings NBA spreads with curl:

```bash
curl --fail-with-body "https://getoddsapi.com/api/v1/odds?sport=NBA&market=spread&fresh_only=true&limit=50" \
  -H "Authorization: Bearer $GETODDS_API_KEY"
```

3. The same request in Python (standard library only):

```python
import json, os, urllib.request

req = urllib.request.Request(
    "https://getoddsapi.com/api/v1/odds?sport=NBA&market=spread&fresh_only=true&limit=50",
    headers={"Authorization": "Bearer " + os.environ["GETODDS_API_KEY"]},
)
with urllib.request.urlopen(req) as res:
    rows = json.load(res)["data"]
for row in rows:
    print(row["away"], "at", row["home"], row["side"], row["line"], row["american"], row["observed_at"])
```

4. Check `observed_at`, `age_seconds` and `stale` on every row before using a price. Full reference: https://getoddsapi.com/docs

## Use with Claude (MCP)

```bash
claude mcp add --transport http getodds https://getoddsapi.com/api/mcp \
  --header "Authorization: Bearer $GETODDS_API_KEY"
```

The MCP tools follow the key's source grants and share its allowance. Setup guide: https://getoddsapi.com/use-with-claude

## Pricing

| Plan | Allowance | Price |
| --- | --- | --- |
| Free key | 1,000 requests a day, 60 a minute | $0, no card |
| Developer Bundle | 10,000 requests or credits a month on each of four sources | $149 a month |

Free development allowance: 1,000 requests per UTC day and 60 per minute per account, with no payment step. Paid: the Developer Bundle at $149 per month, with 10,000 monthly requests or credits on each of four sources.
Details: https://getoddsapi.com/bundle

## Calculator


Canonical page: https://getoddsapi.com/round-robin-calculator
Markdown version: https://getoddsapi.com/round-robin-calculator.md
Language: English. Formula review date: 2026-11-06.

A round robin calculator creates every fixed-size parlay from your selections. The number of bets is the combination count, and total stake is that count times the stake per parlay. The displayed maximum return adds each combination’s payout when every selection wins. Partial wins pay only the combinations whose selections all win.

## Inputs

| Input | Default example | Instructions |
| --- | --- | --- |
| Outcome odds | -110,+150,-200 | Separate each price with a comma. |
| Selections per parlay | 2 | Whole number from 2 to 8, no greater than the selection count. |
| Stake per parlay ($) | 10 | Cash risked, before any winnings. |

## Formula

Bets = n!/(k! × (n − k)!). Total stake = bets × stake per parlay.

## Worked example

Three selections played as two-leg parlays create three bets. At $10 per bet, the total risk is $30.

| Result | Value | Working |
| --- | --- | --- |
| Number of parlays | 3 | 3 choose 2 |
| Total stake | $30 | 10 per parlay × 3 |
| Return if every selection wins | $113.8636 | Sum of stake per parlay × decimal price of each combination |
| Net profit if all win | $83.8636 | All-win return − total stake |

## Assumptions and limits

Uses distinct independent selections. Same-game combinations may be disallowed or priced differently. The all-win return is not an expected value.

Inputs are supplied by the user. These calculators do not fetch live sportsbook prices, estimate a win probability, or recommend selections. Monetary examples use USD. Calculations run in the browser without an account. A shared calculation URL contains its entered numbers.

## Questions and answers

### How does the round robin calculator work?

A round robin calculator creates every fixed-size parlay from your selections. The number of bets is the combination count, and total stake is that count times the stake per parlay. The displayed maximum return adds each combination’s payout when every selection wins. Partial wins pay only the combinations whose selections all win.

### What is the formula?

Bets = n!/(k! × (n − k)!). Total stake = bets × stake per parlay.

### Can you show a worked example?

Three selections played as two-leg parlays create three bets. At $10 per bet, the total risk is $30.

### What assumptions should I check?

Uses distinct independent selections. Same-game combinations may be disallowed or priced differently. The all-win return is not an expected value.

### Does the result include the original stake?

Total return includes a cash stake; net profit subtracts it. A stake-not-returned bonus is explicitly treated differently. Probability and margin outputs are percentages, not cash payouts.

### Can I share my calculation?

Use Copy link to share the current inputs. The URL contains your entered numbers. Calculations run in your browser and do not require an account.

## Embedding

Embed: https://getoddsapi.com/embed/round-robin-calculator
Keep a visible attribution link to the canonical explanation. Embed pages are noindex; use the canonical page for indexing and citations.

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Independent educational product, not affiliated with any sportsbook or pick’em operator. Results are arithmetic, not predictions or betting advice. Only participate where lawful and within limits you can afford.
Responsible gambling resources: https://www.ncpgambling.org/