Round Robin Calculator
Every parlay combination of your selections, costed in real time. Pick group sizes, set per-parlay stake, see the full payout matrix.
"By 2" means every 2-leg parlay combination, "By 3" every 3-leg, and so on.
Approximate (assumes equal-odds legs). Hits below this lose money on the slip overall.
Round robins are insurance. Price the insurance.
A round robin is just a set of parlays. Knowing the cost-per-hit-count is the difference between paying for variance reduction and paying for math you don't understand.
Per-leg EV grading
In the dashboard, every selection in your round robin gets a +EV grade against the no-vig fair price. The slip-level math is only as good as the legs feeding it.
Correlation-aware filtering
Same-game legs in a round robin compound correlation across every parlay. The dashboard flags correlated combinations and lets you exclude them from the round robin set.
Variance-vs-payout slider
Compare a straight parlay against a by-2 round robin against a by-3 with the same legs. The dashboard plots the payout distribution for each so you can pick the variance profile you actually want.
Auto-stake by Kelly
Round robins multiply your effective bet count quickly. The dashboard sizes each parlay by fractional Kelly so a 10-parlay round robin does not accidentally consume 30% of your bankroll.
Frequently asked questions
A round robin is a set of parlays built from every possible combination of your selections at a chosen group size. Pick 4 selections and bet 'by 2' = 6 separate two-leg parlays, one for every pair of legs. You win on each parlay where every leg in that combination wins.
The group size of each parlay in the round robin. By 2 means every pair of selections becomes a 2-leg parlay; by 3 means every trio becomes a 3-leg parlay. With 4 selections: by 2 yields 6 parlays, by 3 yields 4 parlays, by 4 yields 1 parlay (the full straight parlay).
It depends on the selection count and group size. The formula is the binomial coefficient C(n, k). With 5 selections and by 3, you get C(5, 3) = 10 parlays. The calculator displays the count next to each group-size option.
A round robin trades max payout for hit-rate insurance. A 4-leg straight parlay needs all 4 to win or you lose everything. A by-2 round robin still cashes some parlays even if only 2 of 4 win, smoothing variance at the cost of total payout if all 4 hit.
The minimum number of selections that must win for the round robin's total payout to cover the total stake. Below that count, you lose money on the slip overall even if some parlays cash. The estimate assumes equal-odds legs; mixed odds shift the threshold.
Round robins, sized like a pro
The dashboard sizes every parlay in the round robin by Kelly, flags correlated legs, and grades each combination against fair value before you place.