- Pick an Odds Format, set Stake Per Parlay, and choose Parlay Size (2 to 8).
- Add a leg for each selection (up to 12) with its odds.
- Read the output. Number of Parlays, Total Stake, Max Payout, and the scenario grid showing payout per win count.
Round Robin Calculator
A round robin calculator that breaks down every parlay combination in a round robin bet. Enter your legs and stake per parlay to see the total stake and payout.
How to Use This Calculator
What is a round robin calculator?
A round robin calculator breaks a group of bets into every possible smaller parlay combination and shows the total stake required and the payout if each combination wins. Round robins are bettors' way of spreading risk across a group of legs rather than relying on a single all-or-nothing parlay.
If a bettor selects 4 legs and chooses 2-team combinations, the sportsbook creates 6 separate two-leg parlays (every possible pair of the 4 legs). Each parlay is staked individually. If 3 of the 4 legs win, the parlays that did not include the losing leg still cash.
How many combinations are created?
The number of parlays in a round robin equals the binomial coefficient (n choose k), where n is the total legs and k is the combination size:
\[
\begin{aligned}
\binom{n}{k} &= \dfrac{\strut n!}{\strut k!\,(n-k)!}
\end{aligned}
\]
- 3 legs, 2-team combinations: 3 parlays
- 4 legs, 2-team combinations: 6 parlays
- 4 legs, 3-team combinations: 4 parlays
- 5 legs, 2-team combinations: 10 parlays
- 5 legs, 3-team combinations: 10 parlays
Worked example
A bettor selects 4 NFL games and runs 2-team round robins at $10 per parlay.
\[
\begin{aligned}
\text{Parlays} &= \binom{4}{2} = 6 \\[6pt]
\text{Total Stake} &= 6 \times \$10 = \$60
\end{aligned}
\]
If all 4 games win, all 6 parlays pay out. If 3 games win and 1 loses, the 3 parlays that did not include the losing leg still pay out. If only 2 games win, only the 1 parlay containing both winning legs pays out.
Why round robins appeal to bettors
Round robins give bettors exposure to parlay-sized payouts without the all-or-nothing structure of a straight parlay. They also feel safer than they are. The total amount staked grows quickly as the number of combinations increases, and the average expected value per round robin is typically worse than the equivalent set of straight bets, because parlay vig compounds across legs.
Round robins are most common in two scenarios: bettors who want to combine a parlay promotion with multiple legs of conviction, and bettors who want to spread risk across a group of related bets.
To understand the underlying parlay math first, read our What is a Parlay guide. Pair this calculator with the Parlay Calculator for straight parlay math.
Common mistakes
- Underestimating total stake. A 5-leg round robin with 3-team combinations is 10 parlays. At $25 per parlay, that is $250 risked. Always confirm the total stake before placing.
- Assuming each parlay is independent. The parlays share legs. If one leg loses, every parlay containing it loses. The legs are not independent of each other across the parlays.
- Treating round robins as +EV by default. A round robin built from -EV legs is still -EV. The structure does not add edge, it only redistributes variance.
- Mixing legs with very different odds. A round robin with one -300 favorite and three +250 underdogs has heavily skewed parlays that may not behave the way the bettor expects.
Frequently Asked Questions
What is a round robin calculator?
A round robin calculator shows every parlay combination created by a round robin bet, the total stake required, and the payout in each outcome. The DarkHorse Odds Round Robin Calculator supports up to 12 legs and parlay sizes from 2 to 8, with a scenario grid showing the payout for any number of correct picks.
What is a round robin parlay?
A round robin parlay is a wager that automatically splits a group of legs into every possible smaller parlay combination. Instead of one all-or-nothing parlay, a round robin creates many smaller parlays so partial wins still produce a partial payout.
What is the difference between a round robin and a parlay?
A parlay is a single bet requiring every leg to win. A round robin is a collection of smaller parlays built from the same set of legs. Round robins spread risk but cost more in total stake.
How many legs are required for a round robin?
A round robin requires at least 3 legs. The DarkHorse Odds Round Robin Calculator supports up to 12 legs and parlay sizes from 2 to 8.
Are round robins +EV?
Round robins inherit the vig of every underlying parlay, which is generally higher than a straight bet's vig. Without a promotion attached, round robins are typically negative expected value. Sportsbook promotions like parlay boosts can shift the math in the bettor's favor.
Can I round robin same-game legs?
Some sportsbooks allow it, others do not. Even where allowed, correlated legs distort the math because the underlying parlays violate the assumption that legs are independent.
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