Multi-leg bets · the maths
Accumulators
Accumulators are the football bet that gets promoted hardest, and by the arithmetic below they are the worst value on the board. This page is that arithmetic. Accumulators cannot be posted on this site yet — every tip here is a single.
Accumulators cannot be posted yet
A tip on this site is one selection on one fixture, because that is what settles automatically from a result. You can post each leg as a single of its own.
A multi-leg tip needs its own place in the data: every leg, each leg's price and the combined price, and each leg marked won or lost — including the one that broke it. That is not built. When it is, an acca that fell at the last leg will be recorded as the losing bet it is.
Post a singleWhat an accumulator is
An accumulator — an acca, a parlay, a multi — is several bets joined into one. Each individual bet is a leg. Every leg has to win for the accumulator to pay; one loser anywhere in the chain and the whole thing goes down, regardless of how the others finished.
The price is the product of the legs, not the sum. Three legs at 1.80 do not pay 5.40, they pay 1.80 × 1.80 × 1.80 = 5.83. That multiplication is the entire appeal: four ordinary-looking selections turn a 1-unit stake into a 10.5-unit return. It is also the entire problem, and for exactly the same reason.
If a leg is void — a postponed match, a settled-as-void market — it usually drops out and the acca reprices with the remaining legs. Rules vary by bookmaker and by market, so that is a detail worth checking wherever you place the bet rather than assuming.
The odds multiply. So does everything else.
Here is the same leg — offered at 1.80, with a true chance of winning of 52.5% — folded into progressively longer accumulators. These are worked arithmetic from that single assumption, not results from our record. You can recompute every row: the odds are 1.80 to the power of the number of legs, the chance is 0.525 to that power, and the expected return is the two multiplied together.
| Legs | Combined odds | Chance all land | Expected return per 1u staked |
|---|---|---|---|
| 1 | 1.80 | 52.5% | 0.95u |
| 2 | 3.24 | 27.6% | 0.89u |
| 3 | 5.83 | 14.5% | 0.84u |
| 4 | 10.50 | 7.6% | 0.80u |
| 5 | 18.90 | 4.0% | 0.75u |
| 6 | 34.01 | 2.1% | 0.71u |
| 8 | 110.20 | 0.6% | 0.64u |
Illustrative arithmetic · one leg at 1.80 with a true 52.5% chance · not a record of published tips
Read the last column. A single bet at that price returns 0.945 units for every unit staked over the long run, which the table rounds to 0.95u — a 5.5% margin against you, which is a normal football price. Fold the same bet eight times and the expected return drops to 0.64 units. Nothing changed about the selections. The margin was simply applied eight times instead of once, because you are betting through it on every leg.
The middle column is the part people underestimate. A four-fold at these prices lands about 7.6% of the time. The 10.50 payout looks generous next to 1.80 until you work out what it needs: break-even at decimal 10.50 is one winner in every 10.5 tickets — a 9.5% strike rate — against an actual hit rate of 7.6%, or one in thirteen. The gap between those two numbers is the bookmaker's margin, applied four times.
Why long accumulators are a poor bet even when they are fun
There is no trick in the table above and nothing hidden. The arithmetic is public and the bookmakers know it perfectly well, and it is not hard to see why accumulators are advertised so heavily and singles are not. A long acca is a high-margin product with a lottery-shaped payout, and it is sold like one.
Two practical consequences. First, adding a leg to reach a nicer headline price makes the bet worse, not better, whenever that leg carries the bookmaker's margin — and at a normal price it does. The headline went up because the chance went down by more. Second, the variance is brutal in a way that is easy to talk yourself out of. At the numbers above, take any twenty four-folds in a row: the chance that not one of them lands is about one in five. Not once in a lifetime. One time in five.
None of that makes an accumulator irrational if you know what you are buying. It makes it entertainment with a known cost, which is a perfectly reasonable thing to buy, and a completely different thing from an investment.
How to stake one, if you do
Rules worth holding yourself to:
- An acca is staked smaller than a single, and the stake goes out in units alongside the bet so the difference is visible rather than asserted.
- Legs are kept short. The table above is the argument against stretching an acca to reach a nicer-looking price.
- A losing acca is never followed by a bigger one. Chasing a loss with more legs is the most expensive habit in football betting.
- An acca is not a hedge, a system, or a way to cover a bad run. It is one bet with a low chance of landing.
No record on this site includes an accumulator: none can be posted or settled here yet. When they can, they will get a line of their own rather than be folded in with singles — an accumulator and a single are very different bets.
Why explain them at all
Because refusing to would not stop anyone building one. An acca is the bet plenty of people want on a Saturday, and the realistic choice is not between an acca and no acca — it is between an acca published with the maths next to it and one built at speed with none.
If multi-leg tips are added here, the deal will be the same as for every tip: the price recorded at posting, and every one settled into the public record whether it landed or fell at the last leg.