ISP (Industry Starting Price) – Complete Guide to UK Horse Racing Odds

What Is ISP (Industry Starting Price) in Horse Racing?

The Industry Starting Price (ISP) is the odds at which a horse is priced at the exact moment a race begins, calculated from the collective odds of 10 major UK online bookmakers. Introduced in June 2020 as a replacement for traditional on-course bookmaker prices, ISP has become the standard mechanism for settling unsettled bets across the UK horse racing industry.

When you place a bet without taking a fixed price, or when a bookmaker accepts a bet "at starting price," that bet is automatically settled at the ISP. This means ISP directly determines your payout on millions of bets placed daily across UK racing.

How Is ISP Calculated? A Step-by-Step Breakdown

Understanding how ISP is calculated helps you grasp why it matters for your betting decisions. The process is entirely automated and regulated to ensure fairness.

The ISP Calculation Process

Step 1: Data Collection — As a race begins, the system simultaneously captures the final odds from each of the 10 designated online bookmakers. These are the odds they're offering at the exact moment the race goes off.

Step 2: Aggregation — The computer system collects all 10 sets of odds for every horse in the race. This creates a comprehensive snapshot of the market consensus at that precise moment.

Step 3: Calculation — The algorithm calculates a representative price, typically using a weighted average or consensus method that reflects the collective market view. The SPRC oversees this calculation to ensure integrity.

Step 4: Publication — The ISP is published instantly and becomes the official settling price for all bets placed "at starting price" or without a fixed odds selection.

Practical Example: ISP Calculation

Imagine a four-horse race. Here's how the ISP for each horse would be determined:

The ISP for each horse represents the consensus price across the market. This methodology ensures that no single bookmaker's view dominates, and the price reflects genuine market consensus.

When Did ISP Replace Traditional Starting Price?

The June 2020 Transition

The shift from traditional on-course Starting Price to Industry Starting Price occurred in June 2020, during the COVID-19 pandemic. When UK racecourses closed their gates to the public, the traditional system — which relied on manual reporters standing in betting rings at racecourses — became impossible.

Rather than abandon the system temporarily, the UK racing industry and the Starting Price Regulatory Commission (SPRC) implemented a permanent, modernised solution: ISP.

Why the Change Was Necessary

Before 2020, the Starting Price system worked like this: Official reporters would stand at UK racecourses, watching on-course bookmakers shout their odds. These reporters would note the consensus odds just as the race began, compile them, and report back to a central authority. This price became the official SP.

However, this system had inherent limitations:

• Manual process — Dependent on human observers and potential for error
• On-course only — Required physical presence at racecourses
• Slower reporting — Took time to compile and publish
• Limited transparency — Difficult for bettors to verify the process

The pandemic forced a reckoning: Could the system be modernised permanently? The answer was yes. By using the odds from 10 major online bookmakers, the system became:

• Fully automated — Instant, computer-driven calculation
• Always available — Not dependent on racecourse opening hours
• Transparent — Regulated and publicly auditable
• Faster — Published instantly

Permanent Adoption

Even after racecourses reopened and on-course betting resumed, the industry kept ISP. The SPRC recognised that the automated, online-based system was superior to the manual on-course process. Today, ISP is the standard across all UK horse racing.

How Does ISP Compare to Betfair Starting Price (BSP)?

One of the most important distinctions in modern horse racing betting is the difference between ISP and Betfair Starting Price (BSP). While both are called "starting prices," they're calculated in fundamentally different ways — and this difference can significantly impact your profitability.

What Is Betfair Starting Price (BSP)?

The Betfair Starting Price is the odds determined by the balance of back and lay orders on the Betfair Exchange at the moment a race begins. When you bet "at BSP" on Betfair, your bet is matched at the price where the maximum amount of money can be matched between backers and layers.

Key Differences: ISP vs. BSP

Profitability Comparison: ISP vs. BSP

Research from Geegeez (analysing 2023–2024 UK racing data) reveals a stark profitability difference:

For horses priced between 5/1 and 6/1:

• ISP: -£1,826 loss (to £1 level stakes)
• BSP: +£226 profit (to £1 level stakes)

This represents a £2,052 swing in profitability — a difference of over 900% between the two pricing models over two years. Scaled to £20 stakes (a typical betting unit), this would represent a £41,040 difference in actual returns.

Why does BSP outperform ISP so dramatically? The answer lies in overround — the bookmaker's built-in margin. Because ISP is calculated from bookmaker odds (which include their profit margin), the overround is typically higher. BSP, being derived from exchange prices, reflects the true market consensus with minimal margin.

What Is the Difference Between ISP and Best Odds Guaranteed (BOG)?

Best Odds Guaranteed (BOG) is a promotional feature offered by most major UK bookmakers that works in conjunction with ISP (or any starting price).

How BOG Works

When you place a bet with a bookmaker offering BOG, you can take a price early (before the race starts). If the ISP turns out to be higher than the price you took, the bookmaker pays you out at the higher ISP. This effectively removes the risk of taking an early price.

Example:

• You back a horse at 5/1 (taking an early price)
• The race starts and ISP comes in at 2/1
• With BOG: You're paid out at 5/1 (the better price)
• Without BOG: You'd be paid at 2/1 (your taken price)

BOG vs. ISP: When to Use Each

Which bookmakers offer BOG? Approximately 12 major UK bookmakers offer BOG on most UK racing, including the largest operators. It's become a standard feature in competitive online betting.

Who Determines ISP? The Role of the Starting Price Regulatory Commission

The Starting Price Regulatory Commission (SPRC) is the independent body responsible for overseeing the integrity, accuracy, and transparency of the ISP system.

SPRC Responsibilities

Regulatory Oversight — The SPRC ensures that the 10 designated online bookmakers follow standardised procedures for ISP calculation. They audit the system regularly to prevent manipulation or errors.

Integrity Assurance — The SPRC guarantees that ISP reflects genuine market consensus, not the interests of any single bookmaker. This protects bettors from potential price fixing or manipulation.

Transparency Requirements — ISP data is published publicly and made available to bettors, traders, and researchers. This transparency allows anyone to verify that the system is working fairly.

Dispute Resolution — If a bettor disputes an ISP result (e.g., believes it was calculated incorrectly), the SPRC can investigate and adjudicate. While disputes are rare, the mechanism exists to protect consumers.

System Maintenance — The SPRC reviews the ISP system periodically to ensure it remains fit for purpose as the betting market evolves. They also manage the list of 10 bookmakers involved in ISP calculation, ensuring they remain appropriate representatives of the market.

Why Independent Regulation Matters

Before 2020, the Starting Price system was less transparent. The SPRC's involvement with ISP has modernised the regulatory framework, ensuring that bettors can trust the prices used to settle their bets. This is critical because ISP affects millions of pounds in daily settlements.

How Does ISP Affect Your Betting Profitability?

ISP directly determines your returns on a significant portion of your bets. Understanding how ISP impacts profitability is essential for any serious horse racing bettor.

Why ISP Matters to Your Bottom Line

Every bet you place "at starting price" (without taking a fixed price) is settled at ISP. This includes:

• Win bets placed at bookmakers without fixed odds
• Each-way bets where you didn't take a price
• Multiple bets (accumulators, trebles, etc.) settled at SP
• Ante-post bets that didn't have fixed odds locked in

ISP directly determines your payout on all these bets. If ISP is lower than you expected, your returns suffer. If ISP is higher, you benefit.

The Overround Problem

The primary reason ISP affects profitability is overround — the bookmaker's built-in margin. Because ISP is calculated from bookmaker odds (which include their profit margin), the overall overround in ISP-based betting tends to be higher than in exchange betting.

A higher overround means worse odds for bettors. Over time, this compounds into significant losses, even on winning selections.

Historical Profitability Data

Research from the Horseracing Bettors Forum shows that the average overround in ISP has remained relatively stable since 2020, but it's consistently higher than alternative pricing models (BSP, BOG, early prices).

Strategy: When to Use ISP vs. Alternatives

1. Use ISP when: You're betting with a bookmaker and don't have BOG available, or you're placing an ante-post bet
2. Use BOG when: Available — it removes the downside of taking an early price
3. Use BSP when: You're on Betfair and seeking better value; accept the 2–5% commission in exchange for higher odds
4. Use early prices when: You've identified genuine value before the market catches up

Practical Profitability Tip

If you're serious about horse racing profitability, compare your expected value across all available pricing options:

• ISP odds (from a bookmaker)
• BOG odds (if available)
• BSP odds (if on Betfair)
• Early prices (if you've found value early)

Choose the option that maximises your expected value, accounting for commission and overround.

What Is Overround and How Does It Relate to ISP?

Overround is a fundamental concept in betting that directly affects ISP pricing. Understanding overround is key to understanding why ISP odds are often less favourable than alternatives.

Overround Explained

Overround is the amount by which the implied probabilities of all outcomes in a market exceed 100%. Bookmakers build in overround to ensure they make a profit regardless of the result.

Simple Example:

Consider a race with four horses. A bookmaker offers these odds:

• Horse A: 6/4 (implied probability: 40%)
• Horse B: 5/2 (implied probability: 28.6%)
• Horse C: 7/2 (implied probability: 22.2%)
• Horse D: 4/1 (implied probability: 20%)

Total implied probability: 40% + 28.6% + 22.2% + 20% = 110.8%

The extra 10.8% is the overround. It represents the bookmaker's built-in profit margin. No matter which horse wins, the bookmaker makes a profit because the odds are structured so that all possible outcomes total more than 100%.

Overround Per Horse (OPH)

To compare overround fairly across races with different numbers of runners, analysts use Overround Per Horse (OPH), which is the total overround divided by the number of runners.

In the example above:

• Total overround: 10.8%
• Number of runners: 4
• OPH: 10.8% ÷ 4 = 2.7% per horse

An OPH of 2.7% is relatively low. Higher OPH means worse odds for bettors.

How Overround Relates to ISP

ISP is calculated from bookmaker odds, which inherently include overround. Because ISP reflects the consensus of bookmaker prices, the overround in ISP is typically higher than in exchange-based pricing (BSP).

Historical data shows:

• Pre-2020 on-course SP: Average OPH ~2.5–2.8%
• Post-2020 ISP: Average OPH ~2.8–3.2%
• BSP (Betfair): Average OPH ~1.5–2.0% (lower because it's exchange-based, not bookmaker-based)

This difference compounds over time. On a £1,000 bet, a 1% difference in overround represents £10 in additional cost. Over a year of betting, this becomes substantial.

ISP Overround Trends

Research from the Horseracing Bettors Forum tracked OPH from 2016 onwards. Key findings:

• The transition from on-course SP to ISP in June 2020 resulted in a slight increase in average OPH
• However, the increase was modest (from ~2.6% to ~2.9%), suggesting ISP is not significantly worse than the system it replaced
• OPH varies by race type: National Hunt races typically have higher OPH than flat racing

The takeaway: ISP includes overround, which affects profitability. If you're serious about returns, compare ISP against BOG and BSP before placing bets.

Common Misconceptions About ISP

Several myths persist about ISP. Here are the most common ones, debunked:

Myth 1: "ISP Is Always the Best Price Available"

Reality: ISP is often not the best price. Betfair BSP frequently offers higher odds due to lower overround. BOG (Best Odds Guaranteed) can also beat ISP if you take an early price that's higher than the ISP.

Lesson: Always compare ISP against BOG and BSP before deciding where to bet.

Myth 2: "ISP Is Calculated Manually, Like the Old SP"

Reality: ISP is fully automated. A computer system collects odds from 10 bookmakers simultaneously and calculates the consensus price in milliseconds. No humans are involved in the calculation itself.

Lesson: ISP is faster, more transparent, and less prone to human error than the old system.

Myth 3: "All Bookmakers Use the Same ISP"

Reality: The ISP is unified — all bookmakers use the same ISP for settling bets. However, each bookmaker may offer different early prices before the race. The ISP is the same for everyone, but the prices available before the race varies by bookmaker.

Lesson: The ISP is standardised, but shopping around for early prices is still worthwhile.

Myth 4: "ISP Only Applies to Win Bets"

Reality: ISP applies to any bet where you didn't take a fixed price, including each-way bets, multiples, and ante-post bets. If you didn't lock in a price, ISP determines your payout.

Lesson: ISP affects a much broader range of bets than many bettors realise.

Myth 5: "ISP Was Temporary Because of COVID"

Reality: ISP was introduced as an emergency measure in June 2020 but was retained as a permanent system. The racing industry and SPRC recognised that automated, online-based ISP was superior to the manual on-course system.

Lesson: ISP is here to stay, not a temporary measure.

How to Bet at ISP Online

Betting at ISP online is straightforward. Here's the step-by-step process:

Step 1: Choose a UK Bookmaker

Select any major UK bookmaker (Betfair Sportsbook, Paddy Power, Betfred, William Hill, Sky Bet, etc.). All licensed UK bookmakers use ISP for settling bets.

Step 2: Navigate to Horse Racing

Find the horse racing section of the bookmaker's website or mobile app. Select the race you want to bet on.

Step 3: Select Your Bet Type

Choose your bet type:

• Win bet: Back a horse to win
• Each-way bet: Back a horse to win or place
• Accumulator: Combine multiple selections
• Forecast/Tricast: Predict finishing order

Step 4: Don't Take a Fixed Price

Here's the key: Don't select a fixed price. Instead, leave the price field empty or select "at starting price" / "at SP" if the option is available. Some bookmakers automatically default to SP if you don't manually select a price.

Step 5: Confirm Your Stake

Enter your stake and confirm the bet. The bet will now be settled at ISP when the race begins.

Step 6: Race Begins, Bet Settles Automatically

When the race starts, the ISP is calculated, and your bet is automatically settled at that price. No further action is needed on your part.

Practical Scenarios

Scenario 1: Win Bet at ISP

• You place a £10 win bet on a horse without taking a fixed price
• ISP comes in at 4/1
• Your horse wins
• You receive £50 (£10 stake × 4/1 odds) + £10 stake returned = £60 total return

Scenario 2: Each-Way Bet at ISP

• You place a £10 each-way bet (£10 win, £10 place) without taking a fixed price
• ISP comes in at 5/1 for the win odds; place odds are typically 1/4 of win odds (1.25/1)
• Your horse finishes second (doesn't win, but places)
• Place bet pays: £10 × 1.25 = £12.50 + £10 stake = £22.50
• Win bet loses
• Total return: £22.50

Scenario 3: Accumulator at ISP

• You place a £5 four-fold accumulator without taking a fixed price
• All four selections win; their ISPs are 3/1, 5/2, 2/1, and 7/4
• Returns: £5 × (4 × 3.5 × 3.5 × 3) = £5 × 441 = £2,205
• (Note: This calculation is simplified; actual returns depend on bet structure)

ISP in Different Race Types

ISP applies to all UK horse racing, but there are slight variations across different race codes.

Flat Racing

Flat racing is the most common race type and represents the largest volume of betting. ISP works identically in flat racing as in all other race types. The 10 bookmakers submit odds for every flat race, and ISP is calculated accordingly.

Characteristics:

• Highest volume of bets
• Typically lower overround than National Hunt
• Most competitive betting markets
• ISP tends to be most reliable in flat racing due to larger market size

National Hunt Racing

National Hunt (NH) includes steeplechase and hurdle races. ISP applies to all NH races exactly as it does in flat racing.

Characteristics:

• Smaller fields than flat racing (typically 8–15 runners vs. 12–20 in flat)
• Higher overround per horse due to smaller fields
• Less liquid markets (fewer bettors)
• ISP can be slightly less stable in very small fields

All-Weather Racing

All-Weather (AW) racing takes place on artificial surfaces (Polytrack, Tapeta, etc.) and operates year-round. ISP applies to all AW races.

Characteristics:

• Consistent throughout the year
• Similar market dynamics to flat racing
• Growing in popularity and betting volume
• ISP reliability comparable to flat racing

Comparison: ISP Overround by Race Type (2023–2024 Data)

The key takeaway: Flat racing typically offers the most competitive ISP due to larger fields and more betting activity. National Hunt races have higher overround due to smaller fields.

The Future of ISP and UK Horse Racing Betting

ISP has been established as the standard for five years (since June 2020). What does the future hold?

Current Status: ISP as the Standard

ISP is now firmly entrenched as the official settling mechanism for UK horse racing. All licensed bookmakers use ISP, and the SPRC continues to oversee the system. For traditional bookmaker bettors, ISP is the default pricing mechanism.

Regulatory Outlook

The SPRC has shown no signs of changing ISP. The system is working well, and the regulatory framework is stable. However, the SPRC continues to monitor the system and may adjust the methodology or the list of 10 bookmakers if market conditions warrant.

Technology and Automation

The betting industry is increasingly automated. ISP is already fully computerised, but future enhancements might include:

• Real-time transparency: Even more detailed public reporting of ISP calculations
• Faster settlement: ISP published even more instantaneously
• Enhanced regulation: Blockchain or distributed ledger technology for immutable ISP records

Market Evolution: ISP vs. Exchange Betting

The most significant trend is the growing popularity of exchange betting (Betfair BSP). As more bettors discover that BSP offers better odds than ISP, exchange betting continues to grow. This is not a threat to ISP; rather, it reflects a diversification of the betting market.

Coexistence Model: The future likely involves:

• ISP: Remains the standard for traditional bookmaker betting
• BSP: Grows as traders and serious bettors seek better value
• BOG: Continues as a competitive feature for traditional bookmakers
• Early prices: Remain important for ante-post betting and value seekers

Predictions for the Next 5 Years

1. ISP will remain stable — No major changes to the system are expected
2. BSP usage will grow — More bettors will discover and use exchange pricing
3. Regulatory refinement — The SPRC may adjust ISP methodology slightly, but not fundamentally
4. Increased transparency — More detailed public data on ISP calculations
5. Integration with betting platforms — Seamless comparison of ISP, BSP, and BOG odds on betting platforms

The bottom line: ISP is not going anywhere. It's the regulatory standard for UK horse racing. However, serious bettors will increasingly use BSP and BOG as alternatives to maximise their returns.

Frequently Asked Questions About ISP

What does ISP stand for?

ISP stands for Industry Starting Price. It's the standardised odds at which a horse is priced at the moment a race begins, calculated from the consensus of 10 major UK online bookmakers.

When was ISP introduced?

ISP was introduced in June 2020, replacing the traditional on-course Starting Price system. The change was prompted by COVID-19 racecourse closures but was retained as a permanent system due to its advantages.

Who determines the ISP?

The ISP is calculated by an automated computer system using odds from 10 designated UK online bookmakers. The Starting Price Regulatory Commission (SPRC) oversees the system to ensure integrity and transparency.

Is ISP the same for all bookmakers?

Yes, the ISP is standardised across all bookmakers. However, the early prices available before the race may differ by bookmaker. Once the race starts, the ISP is identical for settling all bets.

How is ISP different from BSP?

ISP is calculated from bookmaker odds and includes bookmaker overround. BSP (Betfair Starting Price) is calculated from exchange orders and typically offers higher odds due to lower overround. Over 2023–2024, BSP outperformed ISP by approximately £2,052 per £1 stake on horses priced 5/1–6/1.

Can I choose to bet at ISP?

Yes. When placing a bet with a bookmaker, simply don't take a fixed price. Leave the price field empty or select "at SP" if available. Your bet will then be settled at ISP.

Is ISP better than early prices?

Not necessarily. Early prices may offer better value if you've identified genuine value before the market moves. ISP is useful when you don't have a strong view on value and want to avoid the risk of the odds drifting lower.

What is the difference between ISP and BOG?

ISP is the automatic settling price for bets placed without fixed odds. BOG (Best Odds Guaranteed) is a bookmaker promotion that guarantees you'll be paid at the higher of your taken price or the ISP. BOG removes the downside of taking an early price.

How does overround affect ISP?

Overround is the bookmaker's built-in margin. Because ISP is calculated from bookmaker odds (which include overround), ISP typically has higher overround than exchange-based pricing like BSP. This means ISP odds are often less favourable than alternatives.

Is ISP only for win bets?

No. ISP applies to any bet where you didn't take a fixed price, including each-way bets, multiples, and ante-post bets. If you didn't lock in a price, ISP determines your payout.

Can I bet at ISP on betting exchanges?

Not exactly. On Betfair, you can bet at BSP (Betfair Starting Price), which is similar but calculated differently. Other exchanges have their own pricing mechanisms. Traditional bookmakers use ISP.

Why is ISP important?

ISP affects the payout on millions of bets daily. Understanding ISP helps you make better decisions about when to take fixed prices, when to use BOG, and when to use exchange betting. It's a fundamental concept for any serious horse racing bettor.

Will ISP change in the future?

ISP is stable and unlikely to change fundamentally. However, the SPRC may refine the methodology or adjust the list of 10 bookmakers if market conditions warrant. The regulatory framework is solid and expected to remain in place.

How do I find the ISP for a race?

Most bookmakers display the ISP prominently on their website or app once the race has started. You can also find historical ISP data on racing analysis sites like Geegeez, Racing Post, and Proform.

Is ISP regulated?

Yes. The Starting Price Regulatory Commission (SPRC) is an independent body that regulates ISP. They ensure the system is fair, transparent, and free from manipulation.

Related Terms

• Starting Price (SP) — The original concept that ISP evolved from
• Betfair Starting Price (BSP) — Exchange-based alternative to ISP
• Best Odds Guaranteed (BOG) — Bookmaker promotion that protects against ISP drifts
• Overround — The bookmaker's built-in margin
• Bookmaker — The firms that contribute to ISP calculation
• Each-Way Bet — Bet type often settled at ISP