A straight forecast specifies the first two finishers in order. A straight tricast specifies the first three. Covering other orders buys additional lines: reversing two selections creates two forecasts, while covering all orders of three selections creates six tricasts. With a uniform cash stake, total cost is the line count multiplied by the amount on each line.
This guide reconstructs a same-race ticket, using named Sky Bet and Betfair Sportsbook rules reviewed on 2 November 2026. All runners, results, dividends and stakes in the worked examples are fictional. No account, live offer or real-money bet was tested. The explanation does not establish availability or identical settlement in every country.
Order changes what the line asks for
Betfair's horse-racing rules distinguish straight, reversed and combination forecasts, plus tricasts. In a straight A → B forecast, A must occupy first position and B second. B → A is a different outcome. In an A → B → C tricast, moving C into second place defeats that particular order under an ordinary result.
A reverse forecast funds A → B and B → A. Both runners merely finishing somewhere in the places is insufficient. A third runner between them changes the first-two order that the receipt required. An each-way bet has separate win and place components and needs its own terms.
Combination coverage expands the funded list. It does not remove the order condition from each component. One ordered line can succeed because the ticket also purchased the order that actually occurred.
The distinction from round-robin subset parlays is mathematical as well as practical. An ordinary separate-event AB double is the same subset as BA. In a forecast, those labels specify different finishing positions in one race. An unordered-combination calculator will undercount this ticket.
Count the lines before reading the debit
With n distinct selections, a full combination forecast has n choices for first position and n − 1 remaining choices for second: n(n − 1) lines. A full combination tricast adds n − 2 choices for third: n(n − 1)(n − 2). These formulas count all ordered lines without repeating a runner within one line.
For four selections, the forecast count is 4 × 3 = 12. The tricast count is 4 × 3 × 2 = 24. Choosing three runners out of four gives four unordered groups, but each group has six orders. That is why four groups become 24 tricast lines rather than four.
| Ticket construction | Ordered lines funded | Cost at a fictional 50p on every line |
|---|---|---|
| Straight forecast A → B | 1 | £0.50 |
| Reverse forecast A/B | 2 | £1.00 |
| Full combination forecast from A/B/C | 6 | £3.00 |
| Straight tricast A → B → C | 1 | £0.50 |
| Full combination tricast from A/B/C | 6 | £3.00 |
| Full combination forecast from A/B/C/D | 12 | £6.00 |
| Full combination tricast from A/B/C/D | 24 | £12.00 |
The 50p unit is invented arithmetic, not a minimum stake. Sky Bet's forecast and tricast explanation describes reverse forecasts as two straight bets and lists the expanding combination counts. Its help also distinguishes the quoted-price route from an SP route whose return is initially undetermined.
A whole-ticket budget needs the opposite calculation. Splitting £3 equally across six funded lines allocates 50p to each. Entering £3 on each line would cost £18. Check the confirmed line stakes and debit; do not multiply a displayed whole-ticket total again. Our system-bet stake guide covers that input distinction across other constructions.
Two complete six-line tickets
Take a fictional ordinary race with at least four actual runners. A, B and C finish first, second and third respectively; every selected runner starts. There is no dead heat, disqualification, deduction, bonus, tax, cash out or payout cap. Assume a declared gross forecast return of £12 per £1 for A → B and a gross tricast return of £30 per £1 for A → B → C. These are invented settlement inputs, not current dividends or quoted decimal prices.
Compare two independent purchases: all six forecasts from A/B/C at 50p each, and all six tricasts from those same three at 50p each. Each ticket costs £3. The rows below fully enumerate each purchase; pairing them across the table is a display choice, not one combined bet.
| Forecast line | Forecast gross return | Tricast line | Tricast gross return |
|---|---|---|---|
| A → B | £6.00 | A → B → C | £15.00 |
| A → C | £0.00 | A → C → B | £0.00 |
| B → A | £0.00 | B → A → C | £0.00 |
| B → C | £0.00 | B → C → A | £0.00 |
| C → A | £0.00 | C → A → B | £0.00 |
| C → B | £0.00 | C → B → A | £0.00 |
The forecast purchase returns £0.50 × 12 = £6. Deduct all £3 spent, including the five losing lines, to obtain £3 profit. The tricast purchase returns £0.50 × 30 = £15 and leaves £12 profit after its separate £3 cost. Subtracting only the winning line's 50p would overstate either ticket's net result.
Those amounts depend entirely on the assumed dividends and result. If the forecast gross return were instead £4 per £1, its winning 50p line would return £2. The six-line ticket would then lose £1 overall despite receiving a payment. Break-even in this simple one-winning-line case requires a gross return of £6 per £1, because £0.50 × 6 equals the £3 cost.
Now change the finish to A, D, B, C, with D outside the selected set. None of the six forecasts contains A → D, and none of the tricasts contains A → D → B. Each independent ticket loses its full £3. Buying all orders of selected runners does not cover an unselected runner entering the required positions.
A non-runner can change the product
The following cases apply the named rules to a selected runner declared a non-runner. Assume enough other horses actually run for the remaining market to qualify, a normal result and a usable dividend. These are alternative tickets, not successive changes to one receipt.
| Named product and original line | Withdrawal | Treatment stated in that product's rules |
|---|---|---|
| Sky Bet computer/SP forecast A → B | B does not run | Forecast void |
| Sky Bet computer tricast A → B → C | B does not run | Straight forecast A → C, keeping the remaining order |
| Sky Bet computer tricast A → B → C | B and C do not run | Tricast void |
| Betfair Sportsbook fixed-odds tricast A → B → C | B does not run | The affected fixed-odds tricast is void |
Sky Bet's help gives the computer-tricast reduction and two-non-runner treatment. Betfair's separate fixed-odds section voids a forecast or tricast containing a selected non-runner; it also says a non-runner elsewhere in the race moves settlement to industry dividends. A rule copied from an SP line therefore cannot establish the outcome of a quoted-price line.
No tricast dividend is a separate case. Under Sky Bet's stated fallback, the originally nominated first and second selections form the forecast and the third is ignored. That differs from removing a non-runner wherever it appeared. For A → B → C, a missing tricast dividend retains A → B; B being a non-runner instead leaves A → C under its computer-tricast rule.
These are product-specific examples. Betfair's general Sportsbook rules separate Sportsbook from Exchange and give conflicting sport-specific rules priority. Tote products, overseas racing exceptions and exceptional finishes need their own records. This table does not determine their settlement.
Reconcile the accepted record
Keep the runner names, their specified positions, the race, the product and its price basis. Then preserve every funded line, its cash stake and the total debit. For a reduced ticket, trace each original line through the applicable rule before summing the credited amounts. Two components ending with the same label can still originate from two paid lines; do not delete one just because the labels now match.
A displayed maximum return is not an account credit. Use the final result, actual dividend or accepted price and any stated adjustment. Our starting-price comparison explains why an individual runner's SP should not be substituted for a different return basis. For an unexplained settlement, request the operator's line-by-line calculation alongside the original receipt.
Coverage costs money and can lose the entire amount committed. These examples are for adults legally permitted to gamble in their location, not a recommendation to buy a combination or treat betting as income. Country-specific help is listed on our responsible gambling page.