Single
One selection, one bet. The return is the stake times the odds (RJO, Art. 4(a)): €10 at 1.85 returns €18.50 if the bet wins. If it loses, you lose the €10.
Multiple (accumulator)
You combine several selections in one bet. The odds are multiplied and every selection must be right.
Example with three selections: 1.85 × 1.90 × 2.10 = 7.38. With €5, the possible return is 5 × 7.3815 = €36.91. If one of the three fails, you lose the €5.
Work out other combinations in the bet return calculator.
How the margin compounds
Each selection carries the margin of its market. In a multiple, those margins are multiplied. Imagine three selections, each in a market like 1.85 / 3.60 / 4.20, with a theoretical return of 94.7%:
- Theoretical return of the multiple: 0.947 × 0.947 × 0.947 = 0.848.
- The operator keeps about 15.2% of the stake, against 5.3% on a single.
- As an overround: 1.0564³ = 1.179, or 17.9%.
Every extra selection raises the possible return and also the cost. The guide Bookmaker margin explains the two measures.
Every selection you add multiplies the odds, and the operator’s margin too.
System bet
A system bet is a set of multiples built from the same selections. In a “2/3 system”, the three selections form three doubles, each one a separate bet.
Example with odds of 1.85, 1.90 and 2.10 and €2 per double (€6 in total):
| Correct selections | Doubles paid | Return |
|---|---|---|
| All three | 1.85 × 1.90; 1.85 × 2.10; 1.90 × 2.10 | €22.78 |
| The 2.10 fails | 1.85 × 1.90 | €7.03 |
| The 1.90 fails | 1.85 × 2.10 | €7.77 |
| The 1.85 fails | 1.90 × 2.10 | €7.98 |
| Two or three fail | none | €0 |
With one wrong selection you still receive something, but you placed three bets, and each double carries the margin of two markets.
Which bets exist in Portugal
On licensed sites, sports bets may only cover the sports and competitions on a list approved by SRIJ, which also sets the bet types, when bets can be placed and the result types (RJO, Art. 5(5) and (9)). Bets on youth competitions are prohibited (RJO, Art. 5(6)).
A multiple has a higher possible return because every selection has to be right. Each extra selection adds uncertainty and margin. Only stake what you can afford to lose.
Official sources
- RJO (Annex I to Decree-Law 66/2015), consolidated text published by SRIJ: Arts. 4, 5 and 30 (Portuguese)Checked 15/10/2026
Frequently asked questions
Is the margin of a multiple the sum of the margins?
No, it compounds. With three selections at a 5.3% margin each, the operator keeps about 15.2% of the stake (an overround of 17.9%), not simply the three margins added together.
Does a system bet reduce the risk?
No. It covers more combinations, but each combination is a separate bet you pay for, with its own compounded margin. You can lose the whole amount.
What happens if a match in a multiple is postponed or void?
It depends on the operator’s rules, which must be published on its site together with the rules for calculating prizes (RJO, Art. 30(a)). Read them before you bet.