What Is a Combination Forecast Bet?
A combination forecast is a multiple-selection bet where you pick three to six runners in a race and win if any two of your selections finish first and second in any order. Unlike a straight forecast, which requires you to predict a specific 1-2 finish with just two selections, a combination forecast offers greater flexibility by covering all possible 1-2 combinations from your chosen runners. This makes it an attractive option for bettors who are confident about multiple runners but uncertain about their exact finishing order.
The fundamental appeal of combination forecasts lies in their flexibility. You're not locked into one specific outcome. Instead, you're hedging your bets across multiple permutations, which increases your chances of winning compared to a straight forecast. However, this increased flexibility comes at a cost — the more selections you add, the more individual bets you're placing, and therefore the higher your total stake.
The Core Definition
A combination forecast requires you to select between three and six runners and predict that any two of them will finish in the top two positions, regardless of order. This is distinct from a straight forecast, where you pick exactly two runners and specify which must finish first and which second. With a combination forecast, you're essentially placing multiple straight forecast bets simultaneously to cover every possible 1-2 pairing.
The term "combination forecast" reflects the mathematical nature of the bet — you're creating combinations from your pool of selections. Each combination represents a separate straight forecast bet that is included in your wager.
Why Bettors Choose Combination Forecasts
Bettors opt for combination forecasts for several key reasons. First, they provide a better chance of winning than straight forecasts because you only need two of your selections to finish in the top two, rather than a specific pair in a specific order. Second, they offer a middle ground between the simplicity of a reverse forecast (limited to two selections) and the complexity of a tricast (requiring three positions). Third, they serve as an effective hedging strategy — if you're confident about multiple runners but unsure about their finishing order, a combination forecast allows you to profit from that confidence without the precision requirement of straight forecasts.
| Forecast Type | Selections | Positions | Order Matters | Number of Bets |
|---|---|---|---|---|
| Straight Forecast | 2 | 1st & 2nd | Yes | 1 |
| Reverse Forecast | 2 | 1st & 2nd | No | 2 |
| Combination Forecast | 3–6 | 1st & 2nd | No | 6–30 |
| Tricast | 3–6 | 1st, 2nd & 3rd | Yes | 6–120 |
How Does a Combination Forecast Bet Work?
Understanding how a combination forecast works requires grasping the concept of permutations. A permutation is a specific arrangement of items in a particular order. When you select multiple runners for a combination forecast, you're creating permutations of those runners finishing in the top two positions.
Understanding Permutations and Combinations
When you pick three runners for a combination forecast, you're creating six different straight forecast bets — one for each possible 1-2 pairing. This is calculated using the permutation formula: P(n, r) = n! / (n - r)!, where n is the number of selections and r is the number of positions to fill (2, in this case).
For three selections: P(3, 2) = 3! / (3 - 2)! = 6 / 1 = 6 bets
For four selections: P(4, 2) = 4! / (4 - 2)! = 24 / 2 = 12 bets
For five selections: P(5, 2) = 5! / (5 - 2)! = 120 / 6 = 20 bets
For six selections: P(6, 2) = 6! / (6 - 2)! = 720 / 24 = 30 bets
This mathematical relationship explains why the cost of combination forecasts escalates quickly. Each additional selection doubles or more than doubles the number of individual bets you're placing.
| Number of Selections | Number of Bets | Explanation |
|---|---|---|
| 3 | 6 | 3 × 2 = 6 permutations |
| 4 | 12 | 4 × 3 = 12 permutations |
| 5 | 20 | 5 × 4 = 20 permutations |
| 6 | 30 | 6 × 5 = 30 permutations |
Worked Example with Three Selections
Let's say you're betting on a horse race and you fancy three horses: Horse A, Horse B, and Horse C. You decide to place a combination forecast bet with a unit stake of £1 per bet.
Your combination forecast covers the following six straight forecasts:
- Horse A 1st, Horse B 2nd
- Horse B 1st, Horse A 2nd
- Horse A 1st, Horse C 2nd
- Horse C 1st, Horse A 2nd
- Horse B 1st, Horse C 2nd
- Horse C 1st, Horse B 2nd
Your total stake is 6 bets × £1 = £6.
Now, imagine the race finishes with Horse A in first place and Horse C in second place. This matches combination number 3 in your list, so your bet wins. The payout depends on the odds of that specific 1-2 combination.
If instead Horse B finishes first and Horse A second, that matches combination number 2, and you again win the bet. The key point is that any two of your three selections finishing in the top two positions results in a winning bet.
Scaling Up: Four, Five, and Six Selections
When you increase your selections to four horses, the number of permutations jumps to 12 bets. With a £1 unit stake, your total outlay is £12. This continues to scale: five selections cost £20, and six selections cost £30.
The advantage of adding more selections is that you increase your chances of landing a winning 1-2 combination. The disadvantage is obvious — the cost multiplies rapidly. At six selections with a £1 unit stake, you're committing £30 to the bet. If you're betting at higher stakes, this can become substantial very quickly.
Many bettors find the sweet spot at three or four selections, balancing their confidence in multiple runners against the escalating cost of additional permutations.
What Are the Origins and Evolution of Combination Forecasts?
History of Forecast Betting
Forecast betting emerged in the UK during the mid-20th century as bookmakers sought to offer more varied betting options beyond simple win and place bets. The earliest forecast bets were straight forecasts — simple two-selection bets predicting the exact 1-2 finish. These bets appealed to punters who wanted higher odds and more challenging wagers than standard win betting.
As betting markets matured and punters became more sophisticated, demand grew for more flexible betting options. Bookmakers responded by introducing reverse forecasts, which allowed the same two selections to finish in any order, effectively doubling the number of winning combinations (and doubling the bet count to two).
The logical next step was the combination forecast, which extended the flexibility principle to multiple selections. By allowing three to six selections to compete for the top two positions, combination forecasts democratized forecast betting — they made it accessible to punters who were confident about multiple runners but lacked the precision to predict exact finishing orders.
Why Combination Forecasts Were Created
Combination forecasts filled a genuine gap in the betting market. A reverse forecast with two selections was relatively simple but restrictive. A tricast with three selections was complex and expensive. The combination forecast offered a middle path: more flexibility than a reverse forecast, but simpler and cheaper than a tricast. It allowed bettors to express confidence in a group of runners without committing to a specific finishing order, which is a more realistic assessment of betting knowledge in most cases.
The rise of computerized betting systems and online bookmakers in the late 20th century further popularized combination forecasts. Digital platforms made it easy to calculate permutations and display all possible combinations, removing the manual calculation burden that might have deterred casual bettors.
How Do Combination Forecasts Compare to Other Forecast Types?
Combination Forecast vs. Straight Forecast
A straight forecast is the simplest form of forecast betting. You select two runners and predict which will finish first and which second — the order is crucial. If you pick Horse A to win and Horse B to finish second, but they reverse that order, your bet loses.
A combination forecast, by contrast, removes the order requirement. With three selections (Horse A, B, and C), you win if any two of them finish in the top two positions, regardless of order. This fundamental difference makes combination forecasts significantly easier to win.
Cost comparison: A straight forecast on two selections costs just one unit stake. A combination forecast on three selections costs six times that amount. However, the combination forecast covers six different 1-2 outcomes, whereas the straight forecast covers only one.
Difficulty comparison: Straight forecasts are harder to win because you must predict the exact order. Combination forecasts are easier because you have multiple winning combinations. However, the increased cost means your return per unit stake may be lower.
Combination Forecast vs. Reverse Forecast
A reverse forecast is a two-selection bet that covers both possible finishing orders. It's mathematically equivalent to placing two straight forecast bets — one for each order.
A combination forecast is similar in principle but extends the concept to multiple selections. The key differences are:
- Selection limit: Reverse forecasts are limited to exactly two selections, while combination forecasts allow three to six.
- Permutations: A reverse forecast creates two permutations (two possible orders), while a combination forecast with three selections creates six.
- Flexibility: Both remove the order requirement, but combination forecasts offer greater flexibility by allowing you to include more runners.
Many bettors see a combination forecast as simply an extension of the reverse forecast concept — if you're comfortable with two selections in any order, why not three or four?
Combination Forecast vs. Tricast
A tricast bet requires you to predict the first three finishers in a race. A combination tricast allows three to six selections and covers all possible 1-2-3 combinations from those selections.
The main differences between combination forecasts and tricasts are:
- Positions: Forecasts focus on the top two positions; tricasts focus on the top three.
- Complexity: Tricasts are significantly more complex. With three selections, a combination tricast creates 6 bets (same as a combination forecast), but with four selections, it jumps to 24 bets — double the 12 bets of a combination forecast.
- Cost and odds: Tricasts are more expensive and offer higher potential payouts because they're harder to win.
If you're confident about the top two finishers, a combination forecast is more efficient than a tricast. If you want to predict three positions, a tricast is necessary.
How Do You Calculate Combination Forecast Odds and Payouts?
Understanding Odds in Combination Forecasts
Each of the individual straight forecasts within your combination forecast has its own odds. These odds are determined by the individual odds of the two runners involved.
For example, if Horse A is 4/1 and Horse B is 6/1, the odds for Horse A 1st and Horse B 2nd might be calculated by multiplying the odds: (4/1) × (6/1) = 24/1. However, bookmakers often adjust these calculations slightly, and some use computer straight forecast odds (CSF) rather than fixed odds.
Fixed odds vs. Computer Straight Forecast (CSF): Fixed odds are agreed upon at the time of betting and don't change. CSF odds are calculated after the race based on the actual tote returns, which can result in different payouts. Most bookmakers offer both options, and CSF often provides better value when there are upset results.
When you win a combination forecast bet, you're paid out on whichever specific 1-2 combination actually occurred. If you selected three horses and two of them finished in the top two, you win on that specific combination's odds.
Stake and Total Cost
Calculating your total stake is straightforward: multiply your unit stake by the number of individual bets.
Formula: Total Stake = Unit Stake × Number of Bets
Example: If you place a combination forecast on three selections with a £2 unit stake:
- Number of bets: 6
- Total stake: £2 × 6 = £12
This is why understanding permutations is important — it directly affects how much you'll spend on your bet. A casual bettor might intend to spend £10 but accidentally place a four-selection combination forecast (12 bets) at £1 per bet, committing £12 instead.
Practical Applications: When and Where to Use Combination Forecasts
Combination Forecasts in Horse Racing
Horse racing is the primary domain for combination forecasts. They're particularly useful in races where you've identified multiple horses with genuine winning chances but can't narrow it down to a specific 1-2 order.
Common scenarios for combination forecasts in horse racing include:
- Handicap races: These races often have multiple horses at similar odds, making it difficult to predict exact finishing order. A combination forecast allows you to cover multiple possibilities.
- Large fields: When a race has 12+ runners, identifying three or four genuine contenders is easier than predicting exact order.
- Uncertain ground conditions: When track conditions are variable or unfamiliar, multiple runners might have realistic chances.
- Form analysis: When recent form is mixed or unclear, a combination forecast hedges against uncertainty.
Combination Forecasts in Greyhound Racing
Greyhound racing operates on similar principles to horse racing, and combination forecasts are equally valid in this sport. Greyhound racing often features smaller fields (typically 6–8 runners) compared to horse racing, which can make exact order prediction even more challenging. Combination forecasts are therefore quite popular in greyhound betting.
The mechanics are identical to horse racing — you select three to six greyhounds and win if any two finish in the top two positions.
Other Sports Applications
While less common, combination forecasts can be adapted to other sports with outright markets. For example, in golf, you might place a combination forecast on a tournament winner and runner-up. In tennis, you might forecast the finalists of a tournament. The principle remains the same: select multiple participants and win if any two of them achieve the specified positions.
Common Misconceptions About Combination Forecasts
"A Combination Forecast Is the Same as a Reverse Forecast"
This is one of the most common misconceptions. While both bets remove the order requirement, they're not identical. A reverse forecast is limited to two selections and creates two bets (one for each order). A combination forecast allows three to six selections and creates multiple bets covering all possible 1-2 combinations.
You could think of a combination forecast as an extension of a reverse forecast to multiple selections, but they're distinct bet types with different selection limits and permutation counts.
"More Selections Always Means Better Odds"
This is misleading. While it's true that adding more selections increases your chances of landing a winning 1-2 combination, it also increases your total stake substantially. The odds on individual combinations don't improve — they're determined by the runners' market prices. What changes is your total exposure and the number of ways you can win.
Adding a fourth selection to a three-selection combination forecast doubles your cost (from 6 to 12 bets) but doesn't double your chances of winning — it increases them by only about 50%. This is why many bettors stick to three or four selections rather than going to the maximum of six.
"Combination Forecasts Guarantee a Win"
This is false. A combination forecast wins only if any two of your selected runners finish in the top two positions. If your three selections finish 1st, 3rd, and 4th, you lose the bet entirely. The misconception likely arises from the word "combination," which might suggest covering all outcomes, but combination forecasts are specifically about 1-2 combinations only.
Advantages and Disadvantages of Combination Forecasts
Key Advantages
Increased winning chances: Compared to a straight forecast, a combination forecast has multiple ways to win. With three selections, you have six winning combinations instead of one.
Flexibility without sacrifice: You get the order flexibility of a reverse forecast but with the ability to include more runners. This allows you to express confidence in multiple horses without pinpointing exact finishing order.
Hedging strategy: Combination forecasts are ideal if you've identified a group of strong contenders but lack confidence in their exact order. They allow you to profit from that group-level confidence.
Accessible to casual bettors: The concept is easier to grasp than some other multiple bets, making it appealing to bettors new to forecast betting.
Key Disadvantages
Higher stake required: The cost escalates quickly with each additional selection. A three-selection combination forecast costs six times a single straight forecast, and a six-selection bet costs 30 times.
Diluted returns: While you have more ways to win, each individual combination's odds are typically lower than a straight forecast's odds, since you're covering multiple permutations.
Complexity in understanding: For new bettors, understanding permutations and calculating total stakes can be confusing. Mistakes in calculating the number of bets are common.
Still requires skill: You must still select runners with genuine winning chances. A combination forecast doesn't overcome poor selection; it just spreads the risk across multiple permutations.
Frequently Asked Questions About Combination Forecasts
Q: How many bets is a combination forecast with three selections?
A: A combination forecast with three selections creates six individual straight forecast bets. This is calculated as 3 × 2 = 6 permutations. If your unit stake is £1, your total stake is £6.
Q: What is the difference between a combination forecast and a reverse forecast?
A: A reverse forecast covers two selections in any order (2 bets). A combination forecast covers three to six selections in any order, creating 6–30 bets depending on the number of selections. Reverse forecasts are simpler but more limited; combination forecasts offer greater flexibility.
Q: Can I place a combination forecast with just two selections?
A: No. Combination forecasts require a minimum of three selections. With two selections, you'd place a reverse forecast instead, which covers both possible orders.
Q: How is the payout calculated for a combination forecast?
A: When your combination forecast wins, you're paid out on the specific 1-2 combination that occurred. The odds for that combination are determined by the market prices of those two runners. If you select three horses and two finish in the top two, you win on that specific pairing's odds.
Q: Is a combination forecast better than a straight forecast?
A: It depends on your situation. A combination forecast is easier to win (more winning combinations) but costs more and offers lower individual odds. A straight forecast is harder to win but costs less and offers higher odds. The choice depends on your confidence level and bankroll.
Q: Can you use combination forecasts in sports other than horse racing?
A: Yes, combination forecasts can be adapted to any sport with outright markets, such as golf (tournament winner and runner-up), tennis (tournament finalists), or other competitions with definable first and second positions.
Q: What's the maximum number of selections in a combination forecast?
A: The maximum is six selections, which creates 30 individual bets. Most bookmakers don't allow more than six due to the complexity and cost involved.
Q: How do I calculate the total stake for a combination forecast?
A: Multiply your unit stake by the number of bets. For three selections at £1 per bet: 3 selections = 6 bets, so total stake = £1 × 6 = £6.
Q: Is a combination forecast the same as a combination tricast?
A: No. A combination forecast covers the top two positions; a combination tricast covers the top three positions. A combination tricast with the same number of selections creates significantly more bets and costs much more.
Q: Should I always use combination forecasts instead of reverse forecasts?
A: Not necessarily. If you're only confident about two runners, a reverse forecast is more cost-effective. Combination forecasts are best when you've identified three or more runners with genuine winning chances.