UK horse racing betting has its own vocabulary, and forecast and tricast betting adds another layer of specialist terms on top. If you’ve ever stared at a bet slip wondering what a CSF is, how a reverse forecast differs from a combination forecast, or why the Tote’s Exacta isn’t the same as a bookmaker’s forecast — this glossary is your reference. It covers the language of the forecast from A to Z, with definitions calibrated for punters who place or are considering box bets on British racing.
Terms are ordered alphabetically. Where a term has a direct US equivalent or is commonly confused with another, the distinction is noted.
A to L
Accumulator. A single bet linking selections from multiple races, where each must win for the bet to pay. Not a forecast bet, but sometimes confused with one because both involve multiple selections. An accumulator requires winners; a box forecast requires a finishing order within a single race.
Banker. In box betting, a banker is a horse fixed in a specific finishing position — typically first — while other selections are boxed for the remaining positions. A banker first tricast with one banker and four floaters produces 12 permutations instead of the 60 in a full five-horse box. The banker structure reduces cost at the expense of flexibility.
Box bet. A bet that covers every possible finishing order of a selected group of horses for specified positions. In UK terminology, this is called a combination forecast or combination tricast. The word “box” is informal but widely understood.
Combination forecast. The formal UK name for a box exacta. Covers every first-and-second permutation from a group of three or more horses. Cost formula: n times (n minus 1) times unit stake.
Combination tricast. The formal UK name for a box trifecta. Covers every first-second-third permutation. Cost formula: n times (n minus 1) times (n minus 2) times unit stake.
Computer Straight Forecast (CSF). The algorithm used by UK bookmakers to settle forecast bets. The CSF calculates a dividend based on the starting prices of the first and second finishers. It is not a pool — no money from other bettors influences the payout. CSF dividends on UK races typically range from £15 to over £250 depending on field size and the SPs of the placed horses.
Computer Tricast (CT). The algorithmic extension of the CSF to three finishing positions. The CT takes the starting prices of the first, second, and third finishers and calculates a dividend. CT dividends in competitive handicaps commonly range from £500 to £5,000 or higher.
Dead heat. When two or more horses finish level for a given position. In forecast and tricast bets, a dead heat typically results in the dividend being halved (or divided by the number of dead-heating horses) for the affected position.
Dividend. The payout per unit of stake on a forecast or tricast bet. A CSF dividend of £85 means you receive £85 for every £1 staked on the winning line. If your unit stake was 50p, you receive £42.50.
Each-way. A bet comprising two parts: a win bet and a place bet. Not a forecast bet, but the dominant bet type in UK racing and the most common alternative to combination forecasts for punters evaluating value.
Exacta. The Tote’s pool-based forecast product. The Exacta requires the first two finishers in the correct order (for a straight) or any order (for a box/combination). Settled from the Tote pool, not by the CSF algorithm.
Field size. The number of runners in a race. Field size directly affects forecast and tricast economics: larger fields produce more permutations, higher dividends, and greater box bet value.
Floater. In a banker bet, the selections that are not fixed to a specific position. They are boxed among the remaining places. Also called floating selections.
Forecast. A bet requiring the first two finishers of a race. In UK usage, “forecast” without a qualifier usually means a straight forecast (exact order). A combination forecast or reverse forecast specifies the structure.
Going. The condition of the racing surface — firm, good, soft, heavy for turf; standard, slow for all-weather. Going affects non-completion rates in National Hunt and influences which horses perform best, both of which impact box bet outcomes.
Guaranteed pool. A Tote pool where the operator guarantees a minimum pool size, topping up with house funds if natural stakes fall short. Guaranteed pools reduce the effective takeout and can produce more generous dividends.
Line. A single permutation within a box bet. A four-horse box forecast contains 12 lines. Each line carries the chosen unit stake independently.
M to Z
Market mover. A horse whose odds shorten significantly before the race, suggesting strong support from punters or connections. Market movers in a box bet selection can affect the CSF dividend: if a horse drifts (odds lengthen), its inclusion increases the potential payout; if it shortens, the dividend compresses.
Non-runner. A horse declared to run but withdrawn before the race. Non-runners reduce the field size and may affect the number of places paid in each-way bets. In box bets, a non-runner among your selections reduces your coverage — the permutations involving that horse are voided and stakes returned on those lines.
Official Rating (OR). The BHA handicap rating assigned to each horse, determining the weight it carries in handicap races. The OR is the foundation of handicapping and, by extension, of the competitive fields that produce the best box bet economics.
Overround. The bookmaker’s built-in margin across all outcomes in a race. In win markets, the overround is explicit. In forecast and tricast markets settled by CSF/CT, the overround is embedded in the algorithm.
Pari-mutuel. A pool betting system where all stakes go into a pool, the operator takes a percentage, and the remainder is divided among winners. The US standard for exotic bets. The UK Tote operates on a pari-mutuel basis; traditional UK bookmakers do not.
Part-box. A box bet structure where selections are divided into groups with different positional assignments. Unlike a full box, which treats every horse as equally likely for every position, a part-box reflects a hierarchical opinion — some horses are eligible for first, others only for second or third.
Permutation. One specific finishing order within a box bet. A box forecast on three horses generates six permutations. Each permutation is settled as an independent bet.
Placepot. A Tote pool bet requiring punters to select a placed horse in each of six consecutive races. Not a forecast bet, but part of the Tote’s exotic product range alongside the Exacta and Trifecta.
Pool. The total amount staked by all punters on a specific Tote product for a given race. Pool size determines the dividend: larger pools produce more stable dividends; smaller pools produce more volatile ones. The UK Tote processed over £600 million in pool bets across UK racecourses in 2023.
Quinella. A bet requiring the first two finishers in any order. In US racing, a quinella is a fixed pool product. In UK racing, the closest equivalent is a reverse forecast (for two horses) or a combination forecast (for three or more). The term is not commonly used in UK betting.
Reverse forecast. A bet on two named horses to finish first and second in either order. Produces two permutations at two units of stake. Functionally identical to a two-horse combination forecast.
Starting Price (SP). The official odds of a horse at the moment the race begins, determined by on-course bookmakers. The SP is the primary input for the CSF and CT algorithms.
Straight forecast. A bet on two named horses to finish first and second in a specific order. One permutation, one unit of stake. The cheapest and most precise forecast structure.
Takeout. The percentage deducted by the Tote from the gross pool before dividends are calculated. Typical takeout for Exacta pools is 20 to 25 percent.
Tote. The UK’s pool betting operator, relaunched in 2019. Offers Exacta, Trifecta, Placepot, Jackpot, Quadpot, and Scoop6 pool products on UK horse racing.
Tricast. A bet requiring the first three finishers of a race in the correct order (straight tricast) or any order (combination tricast). Available on races with eight or more runners.
Trifecta. The Tote’s pool-based tricast product. Requires the first three finishers. Settled from the Tote pool, not by the CT algorithm.
Unit stake. The amount wagered on each individual line within a box bet. A box bet’s total cost equals the number of permutations multiplied by the unit stake. Minimum unit stakes at most UK online bookmakers are £0.10 per line.