This glossary of bets offered by UK bookmakers is a non-exhaustive list of traditional and popular bets offered by bookmakers in the United Kingdom. The ‘multiple-selection’ bets in particular are most often associated with horse racing selections but since the advent of fixed-odds betting on football matches some punters use these traditional combination bets for football selections as well.

Types of bet

Win
A bet that produces a return only if the selection comes first in an event (i.e. wins). A win bet may be placed on a single event.

Place
A bet that produces a return only if the selection finishes first or within a predetermined number of positions (places) of the winner of an event. The return is often based on a fixed proportion of the win odds of the selection.

Each-Way
A combination of win and place bets of equal size. Each-Way bets may be placed on a single event or on two or more selections in a multiple bet. Each-Way multiple bets are settled on a win-to-win and place-to-place basis.

Multiple bet
A double, treble or accumulator. A linked series of win singles where all the return from the first selection is automatically staked on the second selection as a win single and so on until all selections have won, thus giving a return, or until one selection loses in which case the whole bet is lost.

Double
A bet on two selections; both of which must win to gain a return.

Treble
A bet on three selections; all three of which must win to gain a return.

Accumulator
A bet on four or more selections; all of which must win to gain a return. Accumulators are often named after the number of selections they contain – thus we can get a fourfold, fivefold or sixfold accumulator (or even higher).

Forecasts
Forecasts are bets on a single event that require the correct forecasting of the finishing order of (usually) the first two or three finishers in the event. Returns on correctly predicted finishing orders are calculated by industry sources via computer software that uses the starting price of all participants in the event, and are usually declared to a £1 stake unit on (mainly) horse and greyhound races.

Straight Forecast
A straight forecast (SF) or computer straight forecast (CSF) is a wager requiring the naming of two selections a and b to finish 1st and 2nd in the correct order in a specified event. Requires a single unit stake. Usually declared on horse and greyhound races of three or more runners. Equivalent to the USA exacta or perfecta, or the Canadian exactor.

Reversed Forecast
A reversed forecast (RF) is a wager requiring the naming of two selections to finish 1st and 2nd in either order in a specified event. It is the same as two straight forecasts on selections a and b: a 1st, b 2nd and b 1st, a 2nd. Requires two unit stakes. Equivalent to a “boxed” exacta/perfecta in North America, where the quinella is a similar wager that requires only one unit stake.

Combination Forecast
A combination forecast is a wager on three or more named selections in order to choose two of the selections to finish 1st and 2nd in the correct order in a specified event. It is the same as the number of straight forecasts on selections a, b … n given by the formula n(n − 1) and therefore requires this number of unit stakes. E.g. 3 selections – 6 bets; 4 selections – 12 bets; 5 selections – 20 bets; etc. Equivalent to boxing an exacta/perfecta with more than two runners in North America.

Tricast
A tricast is a wager requiring the choosing of three named selections a, b and c to finish 1st, 2nd and 3rd in the correct order in a specified event. Requires a single unit stake. Accepted on horse races where 8 or more horses are declared and at least 6 run, and on greyhound races of 5 or more runners that form part of the bookmakers’ main service. In North America, this wager is known as the trifecta (USA) or triactor (Canada).

Combination Tricast
A combination tricast is a wager on three or more named selections in order to choose three selections to finish 1st, 2nd and 3rd in the correct order in a specified event. Requires multiple unit stakes given by n(n − 1) (n − 2) where n is the number of selections. E.g. 3 selections, 6 bets; 4 selections, 24 bets; 5 selections, 60 bets; etc. In North America, this is a “boxed” trifecta.

– https://en.wikipedia.org/wiki/Glossary_of_bets_offered_by_UK_bookmakers#Treble