A round robin takes a group of selections — say five, six, or eight picks across different events — and automatically combines them into every possible smaller multiple of a chosen size, rather than forcing you into one all-or-nothing accumulator. If you round-robin five selections “by doubles,” the system builds all ten possible two-leg parlays from that group. You can also round-robin by trebles, or run doubles and trebles together, and some sportsbooks let you mix sizes in one slip.

The appeal is straightforward: a straight five-fold accumulator needs all five picks correct or it’s dead. A round robin from the same five picks still returns money if only three or four come in, because the doubles or trebles that don’t include the losing leg carry on paying out. You give up the huge single payout of the full accumulator in exchange for a bet that survives the odd bad leg — useful when you like a group of picks as a whole but aren’t confident every single one will land.

The mechanics matter for your stake, not just your winnings. You set a stake per line, and the total amount risked is that stake multiplied by the number of combinations generated — not the stake you typed once. Five selections by doubles is 10 lines; six selections by doubles is 15 lines; add trebles and the count climbs fast. This is the single most common point of confusion with round robins: bettors think of the stake as one number when the book is really placing a dozen or more separate small bets.

Example

You fancy five picks across different sports on the same Saturday:

  1. Real Madrid to beat Bayern Munich in the Champions League @ 1.85
  2. Novak Djokovic to win his US Open quarter-final @ 1.65
  3. Australia to win the Ashes Test @ 2.10
  4. Max Verstappen to win the Belgian Grand Prix @ 1.55
  5. A well-fancied runner in the 3:45 at Ascot @ 4.50

You don’t want a five-fold accumulator, because one outsider losing would sink the whole thing. Instead you round-robin the five by doubles, staking $2 per line. That’s 10 doubles, so your total stake is $20.

Come Saturday evening, four of five win — Real Madrid, Djokovic, Australia, and Verstappen all come through. Only the Ascot runner loses.

Because the horse is involved in four of the ten doubles, those four lines lose. The other six doubles — every possible pairing among the four winners — pay out:

  • 1.85 × 1.65 = 3.0525 → $6.11 on a $2 stake
  • 1.85 × 2.10 = 3.8850 → $7.77
  • 1.85 × 1.55 = 2.8675 → $5.74
  • 1.65 × 2.10 = 3.4650 → $6.93
  • 1.65 × 1.55 = 2.5575 → $5.12
  • 2.10 × 1.55 = 3.2550 → $6.51

Add those six returns together and you get $38.17 back from a $20 stake — a profit of $18.17, even though one of your five picks lost outright. Had you instead placed that $20 as a single five-fold accumulator, the Ascot loser would have wiped out the entire bet for a $20 loss. That gap is the whole point of a round robin.

Key Points

  • You’re trading size for durability: a round robin will never pay what the full accumulator would have paid if everything won, because you’re spreading the same picks across many smaller bets instead of one giant one. Use it when you want protection against one leg failing, not when you’re chasing the biggest possible number.
  • Know your real stake before you confirm: the total risked is stake-per-line times the number of combinations, and that number grows quickly — six selections by doubles is 15 lines, eight selections by doubles and trebles together can run past 80 lines. Always check the total-stake box on the slip, not just the per-line figure.
  • Match the combination size to your spread of confidence: doubles suit a round robin where you think two or three picks might slip; trebles suit a bigger group where you’re comfortable losing one but want protection against two. Mixing both sizes covers more scenarios but multiplies the stake further.
  • The short-priced favorites in your group barely move the needle: your profit comes overwhelmingly from the longer-priced legs surviving into a winning double or treble, so don’t build a round robin around picks that are all short odds — there’s little multiplier effect if every leg is near evens.
  • Terminology varies by sportsbook: some traditional bookmakers use “round robin” for a fixed structure that also includes single bets and “up-and-down” wagers between pairs of selections, alongside the doubles and trebles. On most modern online books, though, “round robin” simply means the multiples-only combination described here — check the bet slip’s breakdown before you confirm, since the bet type name alone doesn’t guarantee which version you’re getting.