Forecast betting is one of horse racing's most traditional bet types in Ireland — the bet slip staple of racecourse punters for generations. The challenge is simple: predict which horse will finish first and second. The complexity is in the variants: straight forecast, reverse forecast and combination forecast each offer different coverage, different costs and different risk profiles. This guide breaks each one down.
Straight Forecast: The Basic Version
A straight forecast requires you to nominate Horse A to finish first and Horse B to finish second, in that exact order. If A wins and B is second — you win. If B wins and A is second — you lose. If either horse finishes anywhere else, you lose.
The straight forecast return is calculated using the CSF (Computer Straight Forecast) formula — a mathematical calculation based on the SP of both horses that produces a dividend. This is not simply the horse's win price: it reflects the probability of both horses filling those specific positions.
Reverse Forecast: Covering Both Orders
A reverse forecast covers both possible orderings of your two selections: A first/B second AND B first/A second. It is effectively two straight forecasts in one bet. The cost is exactly double: a "€1 reverse forecast" costs €2 total.
If A wins and B is second, one leg wins (A/B) and one loses (B/A). Your payout is based on the winning combination applied to €1 (half your stake). If B wins and A is second, the reverse is true. If your two selections fill the first two positions in any order, you win one of the two legs.
The reverse forecast is the most popular forecast type in Irish and British betting shops. It offers insurance against guessing the wrong order while keeping the bet relatively compact.
How the CSF Payout Is Calculated
The Computer Straight Forecast (CSF) is an industry-standard formula. Without going into the full mathematical derivation, it uses both horses' SP to produce a dividend that represents the theoretical return for predicting that exact first-and-second combination. A short-priced horse winning from a long-priced second typically produces a lower CSF than a long-priced winner from a short-priced second — because predicting a short-priced horse to win first is relatively probable.
Bookmakers publish the CSF return after each race, and you can also use Tote forecasts (which are pool-based) rather than CSF — the Tote forecast is sometimes better value and sometimes worse, depending on the specific race.
Combination Forecast: More Selections, More Coverage
A combination forecast takes three or more selections and covers every possible first-and-second combination. With three horses (A, B, C) there are 6 combinations: A/B, A/C, B/A, B/C, C/A, C/B. With four horses there are 12. With five horses there are 20. Each additional selection multiplies the number of bets and the total cost.
Combination forecasts on greyhound racing are particularly popular because six-dog fields produce predictable numbers of combinations. At Irish and British greyhound tracks, combination forecasts are a staple product at the counter.
Forecast vs Exacta: What Is the Difference?
An Exacta is essentially the Tote pool version of a straight forecast: predict first and second in the correct order, settled on the Tote pool dividend rather than the CSF formula. Some bookmakers use "exacta" and "forecast" interchangeably; others treat them as distinct products. If you are unsure which you are placing, clarify with the cashier or the site's terms. 18+ — Gambling Awareness Trust: 1800 753 753, gamblingcare.ie.
Frequently Asked Questions
A straight forecast requires you to predict the first and second place finishers in the correct order. Only one combination is covered — your nominated first must win and your nominated second must finish second.
A reverse forecast covers both possible orderings of your two selections. It is two bets in one and costs double the stated stake. If either combination lands, you win that portion of the bet.
Each leg uses the CSF formula. The payout for the winning combination is applied to half your total stake (the leg that won). The other half covering the non-winning combination is lost.
A combination forecast covers all possible first-and-second combinations from three or more selections. With three selections there are 6 combinations; costs 6× the unit stake.
No. Forecast bets are specific to racing where finishing positions determine outcomes. The equivalent in football would be a correct score bet, which is a different product.