How do I use the Forecast Bet Calculator?
Choose your bet type (Straight Forecast or Reverse Forecast), select your preferred odds format (fractional or decimal), enter the odds for your selections, and specify your stake as either a per‑line (unit) stake or a total stake. The calculator determines the number of lines automatically (1 for a Straight Forecast; 2 for a Reverse Forecast; for combinations it follows n×(n−1) lines, where n is the number of selections) and computes estimated returns. For UK horse racing, most Straight Forecasts with fixed‑odds bookmakers are settled to the official Computer Straight Forecast (CSF) dividend; returns shown here are estimates based on the odds and stake you enter, and actual settlement may vary by bookmaker rules.
- Select bet type: Straight Forecast (finish 1st–2nd in exact order) or Reverse Forecast (covers both possible orders with two lines).
- Pick odds format: fractional (e.g., 5/2) or decimal (e.g., 3.50). You can mix formats across runners if needed.
- Enter odds for your runners. For combinations, add all runners you want covered; the calculator builds every ordered pair automatically.
- Set stake: either enter a unit (per‑line) stake or a total stake. The calculator derives the other value based on the number of lines.
- Review estimated returns. For Reverse Forecasts, remember only one of the two lines can win.
Which odds formats are supported (fractional, decimal)?
The calculator supports fractional and decimal odds—the two standard formats in UK horse racing. Fractional odds (e.g., 5/2) quote profit relative to the stake, while decimal odds (e.g., 3.50) include the return of the stake. Conversions use: decimal = 1 + (numerator ÷ denominator); implied probability = denominator ÷ (numerator + denominator) for fractional, and 1 ÷ decimal for decimal. Decimal values and probabilities below are rounded to two decimals.
| Format | Example input | Meaning (profit on £1) | Decimal (incl. stake) | Implied probability |
|---|---|---|---|---|
| Fractional | 1/5 | £0.20 | 1.20 | 83.33% |
| Fractional | 1/2 | £0.50 | 1.50 | 66.67% |
| Fractional | 5/4 | £1.25 | 2.25 | 44.44% |
| Fractional | 2/1 | £2.00 | 3.00 | 33.33% |
| Fractional | 7/2 | £3.50 | 4.50 | 22.22% |
| Fractional | 9/4 | £2.25 | 3.25 | 30.77% |
| Fractional | 10/3 | £3.33 | 4.33 | 23.08% |
| Decimal | 1.20 | £0.20 | 1.20 | 83.33% |
| Decimal | 3.50 | £2.50 | 3.50 | 28.57% |
- Fractional returns shown by bookmakers typically exclude the returned stake in the “profit” figure; decimal includes it.
- Implied probability does not include bookmaker margin/overround.
Stake options: unit, per line, and total stake
Unit stake and per‑line stake are equivalent terms: the amount staked on each individual line (bet). Total stake is the overall outlay across all lines. The calculator lets you enter either a unit stake or a total stake and automatically derives the other value using the number of lines generated by your selection and bet type.
| Bet type | Selections (n) | Lines | Example input | Derived value | Total stake | Notes |
|---|---|---|---|---|---|---|
| Straight Forecast (SF) | 2 | 1 | £5 per line | — | £5 | Exact 1–2 order only; one line. |
| Reverse Forecast (RF) | 2 | 2 | £2 per line | — | £4 | Two SF lines: A>B and B>A. Only one can win. |
| Combination SF | 3 | 6 (n×(n−1)) | £1 per line | — | £6 | All ordered pairs for A, B, C. |
| Combination RF | 4 | 12 (n×(n−1)) | £0.50 per line | — | £6 | Each unordered pair creates two SF lines. |
| Reverse Forecast (RF) | 2 | 2 | £10 total stake | £5 per line | £10 | Total split equally across two lines. |
| Combination SF | 3 | 6 | £12 total stake | £2 per line | £12 | Total divided by number of lines. |
- Lines for Combination Forecasts scale quickly: n×(n−1). For 5 selections, that is 20 lines.
- Profit/loss for RF is the winning SF return minus the losing line’s stake.
Race Forecast calculator: UK horse racing coverage
This calculator is designed for UK and Irish horse racing across Flat, Jumps (National Hunt), and All‑Weather meetings. It supports Straight Forecasts (SF) and Reverse Forecasts (RF) in races where forecasts are offered—typically events with at least three declared runners. For fixed‑odds bookmakers in Great Britain and Ireland, SF bets are commonly settled using the official Computer Straight Forecast (CSF) dividend published after the race; an RF is simply two SFs in opposite orders, so only the line matching the actual finishing order can win. Because settlement can vary by bookmaker (e.g., deductions for non‑runners or Rule 4, and dead‑heat handling), the calculator provides estimates based on your inputs.
- Coverage: Great Britain and Ireland; Flat, Handicap, Maiden, Novice, Conditions, Stakes, and Jump races.
- Eligibility: Forecasts generally require 3+ runners; in events with fewer runners, forecasts are usually not offered.
- Non‑runners and adjustments: Affected lines are voided or adjusted per bookmaker rules. Use the calculator’s options to reflect non‑runners and typical deductions where applicable.
- Result dependency: Final SF returns usually track the official CSF; RF outcomes reflect the CSF for the actual 1–2 order at your stake per line.
Straight vs Reverse Forecast: which should I choose?
Straight Forecast (SF) and Reverse Forecast (RF) are two‑runner bets for predicting the first two finishers in a horse race. An SF requires the exact 1–2 order; an RF covers both possible orders by placing two SF lines. In Great Britain and Ireland with fixed‑odds bookmakers, Straight Forecast bets are typically settled to the official Computer Straight Forecast (CSF) dividend published after the race; an RF simply places two SFs, so only the line matching the actual finishing order can return. Your choice hinges on conviction about the exact order versus the desire for cover, balanced against total stake and expected value.
- Choose a Straight Forecast if you have a strong view on the exact 1–2 order and want to stake a single line.
- Choose a Reverse Forecast if you expect two runners to dominate but are unsure of the order; note the total stake doubles because there are two lines.
- Remember: only one line can win in an RF; the other line loses its stake.
- Availability: forecasts are generally offered in races with at least three declared runners in the UK and Ireland.
What is a Straight Forecast bet?
A Straight Forecast is a bet picking two named horses to finish first and second in the exact order (e.g., “A to beat B”). It consists of one line, and the stake you set applies to that single line. With fixed‑odds bookmakers in Great Britain and Ireland, settlement is commonly to the official CSF dividend that is declared for the winning 1–2 combination; the return equals the CSF dividend to £1 multiplied by your unit stake. If the order is incorrect, the bet loses.
- Lines: 1 line covering a single order (Horse A 1st, Horse B 2nd).
- Settlement: usually to the official CSF dividend published after the race in GB/IE fixed‑odds markets.
- Stake application: your entered stake is per line (one line only).
- Non‑runner: generally voids the bet because the specified two‑horse combination can no longer occur (check your bookmaker’s rules).
- Dead‑heats: forecasts are settled per the official procedure; returns reflect the published CSF for results affected by dead‑heats.
- Not the Tote: on the Tote, the equivalent bet is an Exacta; dividends and settlement mechanics differ from fixed‑odds CSF.
What is a Reverse Forecast bet?
A Reverse Forecast is two Straight Forecasts on the same pair of horses, covering both possible finishing orders (A>B and B>A). It creates two lines; your per‑line stake is applied to each line, so the total stake is doubled. Only the line matching the actual finishing order can win. Settlement for each line is as per a Straight Forecast, typically using the official CSF dividend for the actual 1–2 order.
- Lines: 2 lines (A>B and B>A).
- Stake application: total stake = 2 × unit stake (one unit per line).
- Outcome: only one line can win; the other line’s stake is lost.
- Non‑runner: if one selection is a non‑runner, both lines are generally void (check bookmaker rules).
- Dead‑heats: returns follow the published CSF for the finishing result that occurred.
Reverse vs Straight payout examples for horse racing
The examples below illustrate how CSF‑based settlement works. Bookmakers commonly settle Straight Forecasts to the official CSF dividend (quoted as a return “to £1”). Your payout for a winning line equals (CSF dividend × stake per line). Net profit equals payout minus your total stake. Actual dividends vary by race, field size, prices, and finishing order; the figures here are example dividends for clarity.
| Scenario | Bet type | Stake per line | Lines | Total stake | Actual 1–2 order | CSF dividend (£ to £1) | Payout (£) | Net profit (£) |
|---|---|---|---|---|---|---|---|---|
| Straight Forecast wins (A>B) | Straight Forecast (A>B) | £2 | 1 | £2 | A>B | £18.40 | £36.80 | £34.80 |
| Straight Forecast loses (wrong order) | Straight Forecast (A>B) | £2 | 1 | £2 | B>A | — | £0.00 | −£2.00 |
| Reverse Forecast wins at higher dividend (A>B) | Reverse Forecast (A/B) | £2 | 2 | £4 | A>B | £18.40 | £36.80 | £32.80 |
| Reverse Forecast wins at lower dividend (B>A) | Reverse Forecast (A/B) | £2 | 2 | £4 | B>A | £10.50 | £21.00 | £17.00 |
Interpretation: a Straight Forecast concentrates stake on a single outcome, maximising profit if your exact order is right but returning nothing if the order is wrong. A Reverse Forecast buys order insurance by splitting stake across both orders; total outlay is higher, so net profit is typically lower than an equivalent winning Straight Forecast when the higher CSF happens to land, but the RF still returns if the alternate order wins at a different CSF.
Advanced forecast perms and combos explained
Permutations let you cover multiple forecast outcomes across one or more races. In the UK and Ireland, forecast bets with fixed‑odds bookmakers are typically settled to the official Computer Straight Forecast (CSF) dividend per race. When you combine forecasts across races (doubles, trebles, accumulators), returns are compounded line‑by‑line: the winning line in leg 1 rolls into leg 2 at the declared CSF, and so on. The calculator automates line building, stake allocation per line, and sequential CSF multiplication, so you can see total stakes, potential returns, and risk concentration before placing a bet.
Forecast Doubles and Accumulator calculator guide
A Forecast Double is a multiple across two races, each leg being a Straight Forecast (SF) or a Reverse Forecast (RF). An Accumulator extends this to three or more legs. Settlement is line‑by‑line: for a winning multiple, payout = stake per line × CSF(leg 1) × CSF(leg 2) × ... × CSF(leg n). The number of overall lines equals the product of lines in each leg (SF = 1 line; RF = 2 lines; combination legs have more). Only the exact finishing orders that match a given line in every leg will return.
- Choose legs: each leg must be a race where forecasts are offered (typically 3+ runners).
- Select SF (1 line) or RF (2 lines) per leg; the calculator multiplies lines across legs.
- Enter stake per line or a total stake; the other is derived from the number of lines.
- Returns are estimated using the CSF “to £1” dividend per winning line in each leg.
| Bet | Legs | Lines per leg | Total lines | Stake per line | CSF per winning line (example) | Payout (calculation) | Total stake | Net result |
|---|---|---|---|---|---|---|---|---|
| Forecast Double (SF × SF) | 2 | 1 × 1 | 1 | £1.00 | £12.50; £9.00 | £112.50 (1 × 12.50 × 9.00) | £1.00 | £111.50 |
| Reverse Forecast Double (RF × RF) | 2 | 2 × 2 | 4 | £1.00 | £12.50; £9.00 | £112.50 (only 1 of 4 lines matches both legs) | £4.00 | £108.50 |
| Mixed Double (SF × RF) | 2 | 1 × 2 | 2 | £1.00 | £12.50; £9.00 | £112.50 (1 winning line if orders align) | £2.00 | £110.50 |
| Forecast Treble (SF × SF × SF) | 3 | 1 × 1 × 1 | 1 | £1.00 | £12.50; £9.00; £7.20 | £810.00 (1 × 12.50 × 9.00 × 7.20) | £1.00 | £809.00 |
- Only lines that match the exact winning orders in every leg return; all other lines lose.
- CSF is a return to £1 stake; multiply by your stake per line to get payout for that line.
- Accumulators grow risk and potential return rapidly; check line counts and total stakes before placing.
Combination Forecast bet calculator: perms and lines
A Combination Forecast covers all possible straight‑order forecasts among a set of selections in a single race. For n selections, there are n × (n − 1) lines because each ordered pair of two distinct runners is a separate Straight Forecast line. A two‑selection combination is equivalent to a Reverse Forecast (2 lines). The calculator builds these lines automatically and computes per‑line or total stakes.
| Selections (n) | Unordered pairs C(n,2) | Ordered pairs per pair | Total forecast lines n×(n−1) | Example unit stake | Total stake |
|---|---|---|---|---|---|
| 2 | 1 | 2 | 2 | £0.50 | £1.00 |
| 3 | 3 | 2 | 6 | £0.50 | £3.00 |
| 4 | 6 | 2 | 12 | £0.50 | £6.00 |
| 5 | 10 | 2 | 20 | £0.50 | £10.00 |
| 6 | 15 | 2 | 30 | £0.50 | £15.00 |
| 7 | 21 | 2 | 42 | £0.50 | £21.00 |
Banker variants in one race are efficient when you have a standout runner:
- Banker to finish 1st with k others for 2nd: k lines.
- Banker to finish 2nd with k others for 1st: k lines.
- Banker to finish 1st or 2nd with k others: 2k lines.
How are dead-heats, non-runners, and Rule 4 handled?
In Great Britain and Ireland, fixed‑odds bookmakers usually settle Straight Forecasts to the official CSF dividend. That dividend already reflects the declared runners, starting prices, and any dead‑heat outcomes. As a result, most adjustments are handled at the CSF level rather than by applying manual deductions to forecast returns. The calculator mirrors this by treating CSF as authoritative for settlement estimates and by voiding or filtering lines when a selection cannot run.
- Dead‑heats: If there is a dead‑heat for first or second, forecasts are settled according to the official CSF publication for that result. Where two outcomes are possible (e.g., dead‑heat for second behind a clear winner), the CSF typically publishes separate dividends for each valid 1–2 combination; only lines matching those combinations can return.
- Non‑runners: Any line containing a non‑runner is normally void. If a race reduces to fewer than three runners, forecast betting for that race is generally void in full. The calculator removes affected lines from the stake and return calculations.
- Rule 4 (deductions): Rule 4 deductions apply to early‑price fixed‑odds singles and multiples when a horse is withdrawn, but CSF‑settled forecasts are not subject to a separate Rule 4 deduction. Instead, the official CSF for the finished race reflects the final field and starting prices. If your bookmaker explicitly offers non‑CSF forecast prices (unusual), their published rules on deductions would apply.
- Abandoned/void race: If a leg is void or abandoned, all forecast lines for that leg are void. In multiples, standard practice is that the multiple is settled on the remaining legs with the void leg treated per bookmaker rules (often as 1.00 for that leg); always check house rules.
Important: settlement policies can vary by bookmaker, but in GB/IE fixed‑odds markets the default is CSF settlement for forecasts. Always check the specific rule summary for the operator you use before placing complex perms or cross‑race multiples.
Can I use this with Ladbrokes, Paddy Power, and others?
Yes. The calculator is bookmaker‑agnostic: you can enter prices taken from any UK or Irish fixed‑odds operator, including Ladbrokes, Paddy Power, BetVictor, Unibet, Parimatch, and others. It estimates returns for Straight Forecasts (SF) and Reverse Forecasts (RF) using the odds and stakes you input. Final settlement is always subject to your bookmaker’s rules; in Great Britain and Ireland, SF bets with fixed‑odds firms are typically settled to the official Computer Straight Forecast (CSF) dividend for the winning 1–2 order, while an RF is two SFs in opposite orders.
- Compatibility: works with fractional or decimal odds copied from any bookmaker slip or racecard.
- No account link: the calculator does not place bets or read your betting account; it is a planning and settlement‑estimation tool.
- Settlement basis: uses your inputs to estimate returns; actual payouts follow the operator’s published rules and the official result.
- Currencies: calculations are unit‑agnostic (e.g., £ or €); results scale with the stake per line you enter.
Forecast bet calculator app: install and offline use
You can install the calculator as a Progressive Web App (PWA) for quick launch and limited offline use. When installed, the core interface loads from your device even without signal, so you can enter odds and stakes on course or in transit. Live prices, results, or CSF dividends still require an internet connection; offline use is for manual data entry and computation only.
| Platform | Supported browser | Install steps | Offline behaviour | Notes |
|---|---|---|---|---|
| iOS/iPadOS 16+ | Safari | Open site → Share → Add to Home Screen → Add | App shell and calculator logic available; manual entries work. No live CSF/results without connection. | Clearing Safari data removes offline cache. |
| Android 9+ | Chrome (or Edge) | Open site → Menu (⋮) → Add to Home screen / Install app → Add | Works as a standalone window; manual calculations offline. Network needed for updates/results. | First load online is required to cache assets. |
| Desktop | Chrome or Edge | Open site → Install (toolbar icon) or Menu → App → Install | Launches in its own window; offline manual use where cached. Internet needed for fresh data. | Behaves like a lightweight app; uninstall via browser app menu. |
- Updates: the PWA refreshes automatically when you’re next online.
- Privacy: no bookmaker credentials are requested or stored.
How to enter prices from UK racecards and settle returns
Racecards in the UK and Ireland typically show fractional odds (e.g., 5/2, 11/4) for early prices or forecast tissue; results pages show the official CSF dividend for the winning 1–2 order after the race. For pre‑race estimates, input your available odds and stake per line. To mirror post‑race settlement, use the official CSF dividend “to £1” for the correct order and multiply by your stake per winning line.
- Identify your pair: choose the two runners you expect to finish 1st and 2nd.
Enter odds:
- Fractional: type as “numerator/denominator” (e.g., 9/4). The calculator converts to decimal internally.
- Decimal: type as a number including stake (e.g., 3.25).
Select bet type:
- Straight Forecast (SF): one line for the exact order (A>B).
- Reverse Forecast (RF): two lines (A>B and B>A); total stake = 2 × unit stake.
- Set stake: enter per‑line stake or total stake; the other value is derived from the number of lines.
After the race (optional for precise settlement):
- Look up the official CSF dividend for the actual 1–2 order.
- Payout for a winning SF line = CSF × stake per line; an RF returns only on the matching line.
- Non‑runners: a line containing a non‑runner is normally void; if the race has fewer than three runners, forecast betting is typically void.
- Dead‑heats: returns track the official published CSF for the recorded result.
Does this work for horse racing only?
The calculator is designed for UK and Irish horse racing, where forecast betting and CSF settlement are standard with fixed‑odds operators. The same line‑building logic (SF = 1 line, RF = 2 lines, combinations = n×(n−1) lines) also applies to other codes that offer forecasts—such as UK greyhound racing—though naming and settlement conventions can differ by sport and operator. It is not intended for Tote Exacta/Trifecta pools (which have their own dividends and mechanics) or for non‑racing sports.
- Horse racing (GB/IE): supported for Flat, Jumps, and All‑Weather where forecasts are offered.
- Greyhound racing: mathematical structure is identical; check the event offers forecasts and confirm settlement rules with your operator.
- Other sports: not applicable (no forecast market).
Why calculators matter: accuracy, pitfalls, and history
Forecast calculators help you plan stakes and estimate returns for Straight Forecasts (SF) and Reverse Forecasts (RF) before you bet. They remove mental arithmetic errors, show how many lines a perm creates, and highlight the trade‑off between coverage and cost. In Great Britain and Ireland, most fixed‑odds bookmakers settle SF bets to the Computer Straight Forecast (CSF) dividend declared after the race; a calculator helps you understand how stake per line interacts with that dividend and how RF or combination perms change exposure.
- Clarity: instantly see lines, total outlay, and estimated payouts for SF, RF, and combinations.
- Consistency: standardised stake handling across different bookmakers and odds formats.
- Risk awareness: reveals how adding selections balloons line count (and cost) in perms.
From paper slips to apps: a short evolution of forecast settling
Before always‑on mobile access, shop staff and results services settled forecast bets manually using declared dividends displayed in betting shops. With online sportsbooks, settlement became automated at scale and CSF dividends are applied programmatically after results are confirmed. Today, calculators and lightweight apps let you simulate complex perms on your phone and understand how CSF‑based settlement and stake allocation will affect your return long before you place a bet.
| Era | How forecasts were entered | How SF bets were settled | User challenges | Typical tools |
|---|---|---|---|---|
| Betting shop (paper slips) | Runner names/numbers written on slips; cashier processed bet | Shop applied the published Straight Forecast dividend after the result | Manual arithmetic for perms and stakes; risk of slip errors | In‑shop dividend boards, calculators behind the counter |
| Early online sportsbooks | Web forms for SF/RF; limited perm builders | Automatic application of the official CSF after results | Hard to preview line counts and compounded returns across legs | Desktop calculators, results feeds |
| Modern mobile/PWA calculators | Tap‑to‑add runners, select SF/RF, set stake per line or total | Post‑race settlement to CSF remains standard for SF; RF is two SFs | Pre‑race dividends unknown; need clear stake‑per‑line logic | On‑device calculators, racecard integration, results look‑ups |
What's the strongest argument against using calculators?
The strongest argument is that calculators can create an illusion of precision before the race. CSF dividends are only known after the result, and different bookmakers may have specific rules on voids and multiples. If you treat a pre‑race estimate as guaranteed, you could over‑stake or misinterpret risk. Calculators are decision aids, not settlement authorities.
- Unknown dividends: CSF is declared after the race; pre‑race figures are illustrative only.
- Operator rules: handling of void legs in multiples, abandoned races, and non‑runners can differ; always check your bookmaker’s rules.
- Data entry risk: mixing total stake and per‑line stake or mis‑ordering selections can distort outcomes.
- Over‑coverage: combination forecasts scale as n×(n−1); costs can exceed bankroll quickly.
- Not pool betting: Tote Exacta/Trifecta use pool dividends, not CSF; a CSF‑based calculator is not suitable for pools.
Mitigations: confirm stake per line vs total stake, sanity‑check line counts, and verify settlement rules with your operator. Where available, cross‑check results and responsible gambling tools provided by your bookmaker and the regulator.
Responsible betting in the UK: limits, age, and support
In the UK you must be 18 or over to gamble. Set deposit and loss limits, consider time‑outs or self‑exclusion if needed, and never chase losses. If gambling stops being fun or you feel out of control, seek help early. Independent support and blocking tools are available and widely recommended by regulators and charities.
- Minimum age: 18+ for betting in Great Britain.
- Account controls: deposit limits, reality checks, time‑outs, and self‑exclusion (availability varies by operator).
- Self‑exclusion services: register with [GAMSTOP](https://www.gamstop.co.uk) to block online gambling accounts with participating operators in Great Britain.
- Helpline: contact the National Gambling Helpline via [0808 8020 133](tel:+448088020133) (24/7) operated by [GamCare](https://www.gamcare.org.uk).
- Information and support: see [BeGambleAware](https://www.begambleaware.org) for advice, and the NHS overview at [NHS gambling addiction support](https://www.nhs.uk/live-well/addiction-support/gambling-addiction/).
- Regulation: learn about rules and consumer protections at the [UK Gambling Commission](https://www.gamblingcommission.gov.uk).
Frequently Asked Questions
Can you place an each-way reverse forecast?
No. Forecasts (straight or reverse) are win-only bets on the exact 1–2 order and do not have an each-way variant. Each-way terms apply to single-runner bets with separate win/place parts, which does not exist for a two-runner forecast market.
What happens to a forecast bet if the field cuts to two runners after withdrawals?
It is usually void because forecasts require at least three runners to be a valid market; the stake is returned. In multiples the void leg is typically settled as 1.00, so a £1 SF×SF double where leg 1 returns a CSF of £12.50 and leg 2 becomes void would pay £12.50 (1 × 12.50 × 1.00).
How do I cap spend on a combination forecast to a fixed budget?
Divide your budget by the line count; per-line stake = total budget ÷ lines. Example: 5 selections create 20 lines; a £10 budget gives £0.50 per line (10 ÷ 20). With 7 selections (42 lines), a £21 budget keeps £0.50 per line (21 ÷ 42).
How do I compare the expected value (EV) of a Straight Forecast versus a Reverse Forecast?
Use EV = sum(probability × payout) − total stake. Example: stake per line £1, SF on A over B with CSF D1 = 18.40 and probability p = 0.25 gives EV_SF = 0.25×18.40 − 1 = £3.60. An RF has two £1 lines; if P(A over B) = 0.25 and P(B over A) = 0.20 with D1 = 18.40 and D2 = 10.50, EV_RF = (0.25×18.40 + 0.20×10.50) − 2 = (4.60 + 2.10) − 2 = £4.70.
Do Rule 4 deductions apply to CSF-settled forecasts?
No. CSF-settled forecasts are not subject to a separate Rule 4 deduction; the official CSF already reflects the final field and SPs. For instance, a 30p/£ Rule 4 that would hit early-price singles has a 0p effect on a CSF-settled forecast; settlement follows the published CSF only.
How are dead-heats for second settled on forecasts, in practice?
The official CSF typically publishes separate dividends for each valid 1–2 pairing created by the dead-heat, and only matching lines are paid. Example: result A wins, B and C dead-heat for second; CSF prints A–B = £7.80 and A–C = £6.90 to £1. A £2 reverse forecast on A/B returns £15.60 on the A–B line (2×7.80) and loses £2 on the B–A line, net £13.60.
How are non-runners handled in a one-race combination forecast?
Lines containing a non-runner are void and removed from settlement. Example: 5 selections create 20 lines; if one is a non-runner, lines drop to 12 (for 4 selections). At £0.50 per line your total outlay falls from £10.00 to £6.00; if you keep total stake fixed at £10.00, the derived per-line stake becomes £10.00 ÷ 12 = £0.83.
Can I use the calculator for greyhound racing forecasts?
Yes, the mathematics is identical: a straight forecast is 1 line, a reverse forecast is 2 lines, and combinations follow n×(n−1). Settlement depends on the greyhound operator’s published forecast dividend rather than horse-racing CSF, so always check the applicable rules for that code.
Is the Computer Straight Forecast (CSF) the same as the Tote Exacta dividend?
No. CSF is a fixed-odds dividend quoted to £1 based on the official algorithm and SPs, while a Tote Exacta is a pool dividend determined by the net pool and winning tickets. On the same race the figures can differ markedly, for example a CSF of £18.40 versus a Tote Exacta of £23.90; you cannot infer one from the other.
How should I handle rounding when splitting a total stake across many forecast lines?
Work to the nearest penny per line and expect a small residual when the split is not exact. For example, £10.00 across 12 lines yields £0.83 per line (£9.96 total) with £0.04 unallocated; either accept the £9.96 total, manually add £0.04 to one line, or adjust the per-line stake to £0.84 and reduce the number of lines you place.
Are forecast bet winnings taxable for bettors in the UK and Ireland?
No. For individuals in the UK and Ireland, gambling winnings are not subject to income tax; the tax burden is on operators, not punters. This is a 0% tax rate on personal betting returns under current regimes, but keep records if you need to evidence source of funds.
How do I target a specific payout using an expected CSF dividend?
Stake per winning line = target payout ÷ expected CSF. Example: to aim for about £50 from a line when you expect a CSF near 12.50, stake ≈ £50 ÷ 12.50 = £4.00; remember the actual CSF may differ, so the realised payout can be higher or lower.
What happens to a forecast multiple if one leg is void or abandoned?
The void leg is usually settled as 1.00 and the multiple continues on remaining legs. Example: a £1 SF×SF double with leg 1 CSF = 9.00 and leg 2 void pays £9.00 (1 × 9.00 × 1.00); in an RF×RF double with four lines, the same 1.00 factor applies to each surviving line.