Round-Robin Parlays Explained

What is a round-robin parlay?

A round-robin is a betting structure that automatically generates every possible smaller parlay combination from a list of selections. With 4 selections, a round-robin “by 2s” produces six 2-leg parlays. You pay for each parlay individually but can lose one or two legs and still cash some of the smaller parlays.

How round-robins work

A round-robin parlay takes a list of selections and automatically builds every possible smaller parlay combination from them. With four selections, a round-robin generates six 2-leg parlays. With five selections, it generates ten 2-leg parlays. The trade-off: more bets cost more money, but you can lose one or two legs and still cash some of the smaller parlays.

How round-robins work

Say you have four NFL selections you like:

• Chiefs −3
• Bills moneyline
• Eagles total Over 48.5
• 49ers −7

A standard 4-leg parlay requires all four to win. Lose any one and the parlay loses.

A round-robin “by 2s” automatically builds all 2-leg parlay combinations:

1. Chiefs + Bills
2. Chiefs + Eagles
3. Chiefs + 49ers
4. Bills + Eagles
5. Bills + 49ers
6. Eagles + 49ers

That’s six 2-leg parlays. Stake $5 on each costs $30 total. If three of your four selections win and one loses, three of the six 2-leg parlays cash. You don’t get the full 4-leg parlay payout, but you don’t lose everything either.

Round-robin sizing

Most sportsbooks let you build round-robins by 2s, 3s, or 4s; combining your selections into 2-leg, 3-leg, or 4-leg parlays.

Selections	By 2s	By 3s	By 4s	By 5s
3	3 parlays	1 parlay	;	;
4	6 parlays	4 parlays	1 parlay	;
5	10 parlays	10 parlays	5 parlays	1 parlay
6	15 parlays	20 parlays	15 parlays	6 parlays
8	28 parlays	56 parlays	70 parlays	56 parlays

Eight selections by 3s = 56 parlays. At $5 each, that’s $280 total stake; round-robins can get expensive fast.

When round-robins make sense

Good use cases:

• You have 4-6 selections you like roughly equally and want to spread risk
• You want some payout even if one leg loses
• You want diversified exposure across a slate of games
• You’re using bonus bets and want to extend their action

Bad use cases:

• You only really like 2-3 of your “selections”; round-robin amplifies weak picks
• You’re trying to chase a big payout (just bet a single parlay)
• Your stake size on each leg is so small the math doesn’t work
• You haven’t calculated total stake before placing

The math: hit rate vs. payout

Round-robins are inherently lower-variance than single parlays:

• 5-leg parlay at -110 each: ~3.5% chance to hit, ~2280% payout
• 5-selection round-robin by 2s (10 × 2-leg parlays): Much higher chance to cash something, much smaller potential maximum payout

You’re trading top-end payout for floor protection. For most casual bettors, that’s a worse expected value because round-robins compound the sportsbook’s parlay margin across multiple bets. For sharp bettors with genuine edges on each selection, round-robins can make sense as risk management.

How to build a round-robin

Most Missouri sportsbooks support round-robins natively:

1. Add 4+ selections to your bet slip
2. Select “Round Robin” or “Combo” option (varies by app)
3. Choose your sizing (by 2s, 3s, etc.)
4. Set per-parlay stake; total stake = stake × number of parlays
5. Review and place

DraftKings, FanDuel, BetMGM, and Caesars all support round-robins. Use our parlay calculator to see what each individual parlay would pay before you commit.

Three rules for round-robins

1. Calculate total stake first. A “$5 round-robin” with 8 selections by 3s is $280 total. Always do the multiplication before placing.
2. Use them when you actually like all your picks. Round-robins amplify weak selections. Picking 5 plays just to fill out a round-robin is a fast way to lose.
3. Don’t round-robin into pure long shots. A round-robin of +500 selections still has tiny hit rates. The format is better suited to spreading moderate plays, not stacking long shots.