Specialty bets: Forecasts
Forecasts are bets on a single event where you need to accurately predict the finishing order of a certain number of participants. Normally, it is the first and second finisher or first, second and third finisher that you need to predict. Forecast bets are normally available for horse racing and greyhound racing only.
The terms below are chiefly used by bookmakers in the United Kingdom. Regardless of country, always check with your specific bookmaker to avoid misunderstandings.
Straight forecast
A straight forecast, commonly abbreviated SF, is a wager where you name two selections (a and b) to finish 1^{st} and 2^{nd} in the correct order. This bet requires a single unit stake.
In the United States, this type of bet is known as exacta or perfecta, in Canada it's called exactor.
Reversed forecast
Just like a straight forecast, a reversed forecast requires the naming of two selections (a and b) to finish 1^{st} and 2^{nd}, but the order isn't important since this bet is actually the same as two straight forecasts on a and b as a 1^{st}, b 2^{nd} and b 1^{st}, a 2^{nd}. Since this is actually two straight forecasts, two unit stakes are required.
In the United States, this type of bet is known as boxed exacta or boxed perfecta. There is also a similar wager available known as the quinella which only requires a one unit stake.
Combination forecast
This bet is a wager on a minimum of three named selections in order to choose two of the selections to finish 1^{st }and 2^{nd }in the correct order. It can be seen as several straight forecasts. The number of selections will determine how many units you are required to stake. Three selections are 6 bets, 4 selections are 12 bets and 5 selections are 20 bets.
In the United States, this type of bet is known as exacta/perfecta with more than two runners.
Tricast
This bet requires you to pick three selections (a, b and c) to finish first, second and third in the correct order. Only a single unit stake is needed.
In the United States, this bet is known as trifecta. In Canada, the name is triactor.
Combination tricast
This is a wager on three or more named selections in order to choose three selections to finish first, second and third in the correct order. The number of unit stakes required will depend on the number of selections. Three selections are six bets, four selections are 24 bets and 5 selections are 60 bets.
In Canada and the United States, this bet is known as a boxed trifecta.
Union Jack
Union Jack is a wager on nine selections. The nine selections are usually placed on a 3 x 3 grid on the betting slip. This bet is usually avoided by professional betters, but it can be a great deal of fun for the hobby punter.
Union Jack can be described as 8 treble bets.
 Let's say the selections AI are placed like this on your betting slip:

A
B
C
D
E
F
G
H
I
 Three trebles are horizontal: ABC, DEF, GHI
 Three trebles are vertical: ADG, BEH, CFI
 Two trebles are diagonal: AEI, CEG

 You must win all three selections in a particular treble to get paid. You can therefore have plenty of wins without receiving any pay, since wins spread out over multiple trebles can be worthless – you need to win all three selections in a particular treble.