A round robin turns a list of picks into many smaller parlays at once. It is a way to keep the big-payout appeal of parlays while not needing every pick to win. It is also easy to misunderstand how much you are actually betting.
How a round robin works
Pick 4 teams and choose "round robin by 2s". The book creates every possible 2-team parlay from your 4 picks:
At $10 each, your total stake is $60, not $10.
How many parlays?
| Picks | By 2s | By 3s | By 4s |
|---|---|---|---|
| 3 | 3 | 1 | — |
| 4 | 6 | 4 | 1 |
| 5 | 10 | 10 | 5 |
| 6 | 15 | 20 | 15 |
| 8 | 28 | 56 | 70 |
Formula: n choose k = n! ÷ (k! × (n − k)!).
Example payout
4 picks at −110, round robin by 2s, $10 per parlay ($60 total). Each 2-leg parlay pays +264 ($26.45 profit, $36.45 returned on $10).
| Picks that win | Parlays that win | Return | Net |
|---|---|---|---|
| 4 | 6 | $218.70 | +$158.70 |
| 3 | 3 | $109.35 | +$49.35 |
| 2 | 1 | $36.45 | −$23.55 |
| 1 or 0 | 0 | $0 | −$60.00 |
Use the round robin calculator for any combination.
The cost of round robins
Every parlay in the round robin carries the compounded margin of its legs. A round robin by 2s at −110 gives up about 8.9% per parlay on average, roughly double a straight bet's 4.5%. (Parlay math.)
Compare with betting the same 4 picks as straight bets at $15 each ($60 total):
- 4 wins: +$54.55
- 3 wins: +$25.91
- 2 wins: −$2.73
- Expected loss at 50% legs: −4.5%
The round robin has higher variance (bigger upside when you are hot) and a higher expected cost.
When a round robin can make sense
- Every pick is +EV. Then parlays compound the edges, and a round robin spreads the risk across combinations. (How to find +EV bets.)
- Underdog-heavy cards, where a couple of hits pay off well
- Promotions that boost parlays or refund losing legs
If your picks are not +EV, a round robin just increases the margin you pay.
Tips
- Always check the total stake before confirming
- Avoid same-game legs in a standard round robin (often not allowed or priced differently)
- Smaller "by" sizes (2s, 3s) keep variance and margin lower than big parlays
Frequently asked questions
What is a round robin bet?
A set of smaller parlays created from a list of picks. A round robin by 2s from 4 picks creates 6 two-team parlays.
How much does a round robin cost?
The number of parlays times your stake per parlay. 4 picks by 2s at $10 each costs $60.
Is a round robin better than a parlay?
It is less all-or-nothing than one big parlay, but it still carries parlay-level margin on every combination. It is only +EV if your picks are.