Is it better to back a horse in the morning or wait until the starting price?
The answer depends on which horse you are backing, how its odds move and whether the available price represents value.
Early prices can be attractive when a horse is heavily backed before the race. A runner available at 8/1 in the morning might start at 4/1, leaving anyone who secured the earlier price with a substantially bigger potential return.
But the opposite happens regularly.
A horse available at 4/1 in the morning might drift to 8/1 by the off. Someone who backed it early has accepted half the potential profit available to a punter who waited.
Historical research into British racing markets suggests that taking early prices indiscriminately is unlikely to be the best approach.
The evidence also shows why the relationship between early odds and starting price is more complicated than simply following horses whose prices shorten.
What Is the Difference Between Early Prices and Starting Price?
Early prices are bookmaker odds available before the racecourse betting market opens.
They may be offered the evening before a race, overnight or during the morning.
The starting price, usually abbreviated to SP, is the official industry price returned when the race begins.
SP reflects the betting market close to the off rather than the price available several hours earlier.
Between those points, bookmakers adjust their odds in response to betting activity, market information and changes to the race.
Horses may shorten in price, drift or remain at approximately the same odds.
Our Starting Price betting guide explains how the official SP is calculated and how it differs from accepting a fixed price.
Example: Backing a Horse Early
Suppose a horse is available at 8/1 in the morning.
You place a £10 win bet.
The horse is subsequently backed into 4/1.
If it wins, your early bet returns £90, including the original stake.
The same £10 bet at 4/1 SP would return £50.
By taking the early price, you secured £40 more in total returns.
However, that does not establish that the original 8/1 bet was good value.
To answer that question, you also need to consider the horse’s actual chance of winning.
What Does the Historical Research Show?
Several publicly accessible studies have examined how British racing odds change before the off.
The research covers different periods, race types and price sources, so the findings should not be combined as though they came from one dataset.
Three studies are particularly informative.
| Research | Sample | Main Finding |
|---|---|---|
| Geegeez, 2018–2022 | Five years of UK Flat and all-weather racing | More horses drifted than shortened between early morning and opening show |
| Geegeez, 2021–2024 | UK Flat and all-weather racing | Price movements across the day were associated with substantial differences in strike rates |
| Smart Betting Club, 2020 | 30,861 runners | Earlier Betfair prices were often more attractive for shorter-priced runners, while BSP compared favourably for outsiders |
These are findings from independently published research, not a new British Racecourses backtest.
The distinction matters because the studies use different definitions of early prices and different starting-price measures.
The findings also relate to the periods examined. They should not be assumed to describe every current bookmaker or race market.
More Horses Drift Than Shorten From Morning Prices
One of the most revealing findings comes from research by Dave Renham, published on Geegeez in October 2023.
The study examined UK Flat and all-weather racing between 2018 and 2022, using William Hill bookmaker prices.
It compared early morning odds, generally available around 9am, with the opening show shortly before racing.
The findings were:
| Morning-to-Opening Movement | Percentage of Runners |
|---|---|
| Drifted | Approximately 53% |
| Shortened | 36.4% |
| Unchanged | Approximately 11% |
Source: Dave Renham, Geegeez, Steamers and Drifters: Part 3, October 2023.
These results challenge the assumption that early prices are generally bigger than those available closer to the race.
In this sample, horses were considerably more likely to drift than shorten.
That means a punter backing every selection at the morning price would frequently have missed the opportunity to obtain better odds later.
What Does This Mean in Practice?
Imagine backing a horse at 5/1 in the morning.
If it drifts to 7/1, the earlier bet is now at a disadvantage in terms of potential payout.
The original wager might still have represented value when it was placed.
However, the later price is more attractive for someone making the same selection, assuming the horse’s circumstances have not changed in a way that alters its chance.
The historical evidence suggests that waiting can be beneficial for many runners.
It does not prove that waiting is always the correct strategy.
For readers unfamiliar with market terminology, our horse racing betting glossary explains drifters, steamers, SP and other commonly used expressions.
Do Horses That Shorten in Price Win More Often?
Research suggests that horses whose prices shorten tend to win more frequently than those whose odds drift.
That is understandable.
A horse attracting support may already be considered a stronger contender, while drifting runners often begin at bigger prices and have lower expected winning probabilities.
However, market movement can also reflect new information.
A horse might shorten following positive betting activity, a change in conditions or a reassessment of its chance.
The important question is whether shortening prices provide information beyond what was already reflected in the original odds.
What the Geegeez Research Found
Renham’s 2023 study found that horses shortening from early morning odds to the opening show had a substantially higher strike rate than those drifting over the same period.
However, when returns were calculated at Betfair Starting Price, the differences between the main movement groups were much smaller.
This is an important distinction.
A higher strike rate does not automatically mean better betting value.
Short-priced horses naturally win more frequently than outsiders.
To assess profitability, the winning returns must be compared with the total stakes.
Why Shortening Odds Are Not Proof of Value
Suppose a horse is backed from 10/1 into 5/1.
Its shortening price may indicate that the market now considers it more likely to win.
But a bet at 5/1 is only attractive if the horse’s true chance is better than the probability implied by those odds.
If the horse’s realistic chance is 15%, odds of 5/1 would be too short.
The fact that the horse was available at 10/1 earlier does not make 5/1 good value.
Understanding how to convert prices into probabilities is essential. Our betting odds guide covers fractional and decimal odds, implied probability and the relationship between price and risk.
Do Drifters Offer Better Value?
A drifting horse is one whose odds become longer before the race.
For example, a runner might move from 3/1 in the morning to 6/1 at SP.
That movement can make the horse more attractive from a price perspective.
However, there may be a reason for the drift.
The market might have reassessed the horse’s chance because of ground conditions, the strength of its opposition or other information.
A drift is not automatically an opportunity.
Why the Bigger Price Matters
Consider a horse with a realistic 20% chance of winning.
At 3/1, its decimal odds are 4.00, implying a 25% chance before accounting for the bookmaker’s margin.
That price would be unattractive if the 20% estimate were correct.
At 6/1, the decimal odds are 7.00, implying approximately a 14.3% chance.
The later price would be much more attractive.
But the calculation depends on the original 20% estimate remaining valid.
If new information reduces the horse’s chance to 10%, even 6/1 may represent poor value.
The challenge is distinguishing an excessive market drift from a justified reassessment.
What Happens When Horses Shorten or Drift Throughout the Day?
A later Geegeez study examined UK Flat racing from January 2021 to August 2024.
It separated runners according to how their prices moved between early morning, opening show and SP.
The findings provide further evidence that market movements are not straightforward.
Horses That Shortened Twice
Horses whose odds shortened from early morning to opening show and then shortened again to SP had a strike rate close to 20%.
The group produced an actual-to-expected ratio of approximately 0.91.
Returns at industry SP showed losses of around 12p per £1 staked.
Returns at Betfair SP were better, but still showed a loss of slightly more than 4p per £1.
These figures show that horses attracting sustained support can win relatively frequently without necessarily being profitable to back indiscriminately at SP.
Horses That Drifted Twice
Horses whose odds drifted across both periods had a much lower strike rate, winning approximately one race in sixteen.
Their actual-to-expected ratio was around 0.81.
Backing the group at industry SP produced losses of approximately 34p per £1 staked.
The losses were smaller at Betfair SP, but still exceeded 12p per £1.
This suggests that sustained drifts were often associated with relatively weak performance in that historical sample.
However, the analysis does not establish whether the morning odds on those horses would have been profitable.
That would require a separate calculation using the early prices and the actual results.
An Important Finding About Early Shorteners
The same research found that only around 35% of horses priced at 9/1 or shorter that had shortened between early morning and opening show continued to shorten through to SP.
Many drifted back out before the race.
That illustrates why an early market move should not be assumed to continue.
A horse shortening at lunchtime might still be available at a bigger price shortly before the off.
Are Early Prices Better for Favourites?
There is evidence that the answer can differ according to the odds range.
A 2020 Smart Betting Club study examined 30,861 runners using historical Betfair exchange prices.
The researchers compared available prices at intervals from two hours before the off through to Betfair SP.
This was an exchange-market study rather than a comparison of early bookmaker prices against official industry SP.
Nevertheless, it provides useful evidence about the timing of bets.
Short-Priced Horses
For runners in the decimal odds range 1.01 to 1.99, the study found average available prices of 1.69 around 60 minutes before the race compared with an average BSP of 1.64.
The earlier prices were generally more attractive for these short-priced runners.
Small differences at short odds can have a meaningful effect on long-term returns.
For example, a £10 winning bet at decimal odds of 1.69 returns £16.90.
At 1.64, it returns £16.40.
The difference is only 50p for one winning bet, but repeated price improvements can accumulate over a large number of selections.
Mid-Range Prices
In the decimal odds range 5.00 to 6.99, the study found very little difference between the average prices available at different times.
The figures were approximately 5.90 to 5.92.
This suggests that, for this particular sample, the timing of a bet was less significant within that price range.
It does not mean every individual runner followed the same pattern.
Bigger-Priced Outsiders
For longer-priced horses, the study found that Betfair SP often compared more favourably with earlier exchange prices.
In the decimal odds range 15.00 to 21.99, the average BSP was 18.00, compared with earlier average prices between 17.75 and 17.87.
The difference became more pronounced among very large outsiders.
For the 2,262 runners in the study’s 100.00-plus price category, average BSP was 392.44 compared with average odds of 230.78 two hours before the off.
Extreme prices require particular caution because averages can be influenced by unusual observations and market liquidity.
The study also predates current market conditions.
Its findings should be treated as historical evidence rather than a guarantee that the same patterns persist.
Early Prices vs SP: Worked Betting Examples
The following calculations are illustrative and use fictional horses.
They demonstrate how the same selection can produce different returns depending on when the bet is placed.
| Horse | Early Odds | SP | £10 Win Return at Early Odds | £10 Win Return at SP |
|---|---|---|---|---|
| Horse A | 8/1 | 4/1 | £90 | £50 |
| Horse B | 3/1 | 6/1 | £40 | £70 |
| Horse C | 5/1 | 5/1 | £60 | £60 |
| Horse D | 10/1 | 7/1 | £110 | £80 |
All returns include the original stake and assume the horse wins.
For losing selections, the £10 stake is lost in either case.
You can use our horse racing bet calculator to compare the potential returns from different prices and stakes.
The Difference Over Several Winning Bets
Suppose a punter backs ten winning horses at 8/1.
The total returns from ten £10 stakes would be £900.
If the same ten horses returned an SP of 4/1, total returns would be £500.
The early prices would have produced £400 more.
However, this is not a realistic betting-system test because it considers winners only.
A proper test must include every selection, including losing bets.
It must also use the prices actually available at the time the selections were made.
Why Beating SP Does Not Guarantee a Profit
Beating the starting price means securing odds bigger than the eventual SP.
For example, taking 6/1 about a horse that starts at 4/1 is beating SP.
This can be a useful measure of price quality.
However, it does not guarantee that a betting strategy will be profitable.
Suppose a system regularly secures odds of 6/1 about horses that start at 5/1.
That may indicate an ability to identify prices before the market shortens.
But if those horses win only 10% of their races, the bets would still lose money over time at 6/1.
The break-even winning percentage at 6/1 is approximately 14.3%.
At a 10% strike rate, the strategy would remain unprofitable despite consistently beating SP.
Closing-Line Value and Actual Returns
Closing-line value in horse racing compares the odds secured with a price available near the start of the race.
It can help evaluate whether selections are regularly obtaining prices that later become less attractive.
But it is not the same as realised profit.
A complete assessment needs both:
- Price performance: Whether the selections consistently beat a suitable closing-price benchmark.
- Betting performance: Whether the actual results produce positive returns after losing stakes and applicable costs.
A strategy can perform well on one measure and poorly on the other over a limited sample.
Why Bookmaker Margins Matter
A bookmaker’s odds are not a neutral representation of each horse’s chance.
The prices generally incorporate a margin.
If every runner’s implied probability is added together, the total will usually exceed 100%.
The amount above 100% is known as the overround.
For example, a market with implied probabilities totalling 115% has a 15% overround.
That does not mean every selection is equally overpriced.
The bookmaker may have allocated more of its margin to some runners than others.
It does mean that backing horses indiscriminately at the available prices is generally unattractive.
The margin is one reason the distinction between early prices and SP matters.
An early bookmaker market may have a different overround from the market close to the off.
Even if a horse’s underlying chance has not changed, the price available can move as the bookmaker adjusts its overall market.
Comparing odds across bookmakers can therefore be as important as deciding when to place the bet.
How Best Odds Guaranteed Changes the Decision
Best Odds Guaranteed, usually abbreviated to BOG, is particularly relevant when comparing early bookmaker prices with SP.
Where the promotion applies, a qualifying bet is settled at the bigger of the early price taken and the official SP.
Suppose a horse is backed at 5/1.
If it shortens to 3/1 SP, the bet retains the 5/1 price.
If it drifts to 8/1 SP, the bet is settled at 8/1.
This removes one of the main disadvantages of accepting an early price.
However, BOG is subject to bookmaker terms, qualifying periods, eligible markets and other restrictions.
Not every early bet qualifies.
Some offers also exclude particular races or bet types.
Our Best Odds Guaranteed bookmaker comparison explains the concession and compares the terms offered by different bookmakers.
Does BOG Make Early Betting Profitable?
No.
BOG can improve the settlement odds of qualifying winning bets, but it does not change the result of the race.
A selection can still represent poor value even when BOG applies.
The promotion is best understood as a potential improvement to the price received, not as a profitable strategy in itself.
An Example Using bet365
The bet365 Best Odds Guaranteed guide provides a practical example of how an individual bookmaker applies the concession.
At the time of writing, bet365 advertises BOG for new and eligible customers on qualifying horse racing bets placed from 8am UK time on the day of the race, subject to its terms.
A horse backed at 6/1 that wins at 9/1 SP would ordinarily be settled at 9/1 where the wager qualifies.
If the same horse shortened to 4/1, the original 6/1 would remain the better price.
The important consideration is eligibility.
A bookmaker may offer BOG only during specified periods, to certain customers or on particular markets.
Always check the terms applying to the individual bet.
Should You Bet the Night Before a Race?
Taking prices the evening before racing introduces additional uncertainty.
Bookmakers may have limited information about the final field, going and likely market conditions.
The price may be attractive if the horse is subsequently supported.
But an overnight bet can also be exposed to changes that make the selection less appealing.
Examples include:
- A deterioration in ground conditions.
- A significant change in the expected pace.
- Non-runners altering the race.
- Updated information about the horse or its opposition.
- The market moving to a substantially bigger price.
Overnight prices can also be subject to different promotional terms from morning prices.
The public studies discussed here do not establish that overnight bookmaker prices are generally better than morning prices.
That is a separate question requiring historical overnight odds data.
How Is This Different From Ante-Post Betting?
Early prices on the day of a race should not be confused with ante-post betting.
Ante-post wagers are placed before the final declarations, sometimes weeks or months in advance.
They can involve different non-runner rules and promotional conditions.
An early morning bet on a declared runner is therefore a different proposition from taking a price about a horse for a major festival race several months away.
When Might Waiting Until SP Be Better?
Waiting may be sensible when the horse’s chance is particularly sensitive to late information.
For example, a runner with uncertain ground suitability may become more or less attractive as conditions develop.
Likewise, the withdrawal of a prominent front-runner can change the likely pace of a race.
A bettor who waits can incorporate that information before making a decision.
However, the price may also shorten while they wait.
There is no way to guarantee that the final odds will be more attractive.
The decision should reflect the horse’s estimated chance, the available price and the importance of information still to emerge.
Why Comparing Bookmakers Matters
The decision is not always limited to taking an early price or waiting for SP.
Different bookmakers can offer different prices on the same horse at the same time.
One bookmaker might offer 9/2 while another offers 5/1.
If the selection wins, the second price produces a bigger return.
That difference exists regardless of how the horse’s odds subsequently move.
It is therefore useful to compare the available fixed prices before deciding whether to place a bet.
Bookmakers may also differ in their BOG eligibility, each-way terms and settlement rules.
Our guide to comparing horse racing bookmakers examines the features that matter beyond headline odds.
For a broader comparison of operators, see our best horse racing betting sites guide.
The strongest quoted price is only useful if the bet can actually be placed and the relevant terms are acceptable.
How to Compare Early Prices and SP Properly
A reliable historical analysis needs to compare the same selections at different price points.
It should not select horses retrospectively because their odds shortened.
That would introduce hindsight into the results.
A practical test should follow these steps.
1. Define the Selection Method
Establish how horses are selected before examining their subsequent price movements.
For example, a strategy might select horses using official ratings, trainer form or another measurable factor.
The selection criteria must remain consistent.
2. Record the Early Price
Record the bookmaker, odds and exact time at which the price was available.
An 8/1 quote at 8am is not equivalent to an 8/1 quote available shortly before the race.
3. Record the Official SP
Use the official industry starting price for the same horse and race.
Do not substitute Betfair SP without identifying it separately.
4. Record the Result
Include winners and losers.
Exclude or account for non-runners according to the settlement rules being tested.
5. Apply Consistent Stakes
Use the same stake for every selection when comparing the effect of price timing.
That isolates the price difference from changes in staking.
6. Calculate Returns
Compare total returns, profit or loss and return on investment at early prices and SP.
For an each-way strategy, the place terms must also be recorded.
7. Examine Different Price Ranges
Separate favourites, mid-priced runners and outsiders.
The historical evidence suggests that price movement patterns can differ substantially between these groups.
8. Check Whether the Findings Persist
A result based on a few dozen bets can be heavily influenced by chance.
Use a substantial sample and examine whether the findings remain similar across different periods.
Our guide to backtesting a horse racing betting system explains how to avoid misleading results, selection bias and unrealistic assumptions about historical prices.
Why Public Racing Data Has Limitations
Historical SP and race-result data are easier to obtain than comprehensive early bookmaker prices.
Betfair publishes historical starting-price files, including exchange SP and other aggregated market information.
These can support research into exchange-market behaviour.
However, Betfair SP is not the same as the official industry SP.
Likewise, a bookmaker’s closing price is not necessarily identical to SP.
Historical studies may also use different bookmakers, price collection times and rules for handling non-runners.
These differences can materially affect the results.
A credible analysis should identify its exact data sources and avoid combining incompatible price types without explanation.
Why Exchange Commission Matters
A raw comparison between BSP and bookmaker SP can be misleading if the exchange’s commission and applicable charges are ignored.
Suppose an exchange offers bigger decimal odds than a bookmaker.
The apparent advantage may be reduced when commission is applied to winnings.
The relevant comparison is the return actually received after applicable charges, not simply the displayed odds.
The same principle applies when comparing different bookmaker promotions.
The settlement rules can alter the effective price of a winning bet.
Early Prices vs Starting Price FAQs
Are early horse racing prices usually better than SP?
Not necessarily. Historical UK Flat racing research found that more horses drifted than shortened between early morning prices and the opening show. The best time to bet depends on the individual horse and the available odds.
Do horses that shorten in price win more often?
Historical research has found higher strike rates among horses whose odds shorten. However, shorter-priced horses are generally expected to win more frequently, and a higher strike rate does not guarantee profitable returns.
Is it better to back favourites early?
Some historical exchange-market research found that earlier prices were often more attractive for shorter-priced horses. This does not establish that every favourite should be backed early or that early bookmaker prices always beat industry SP.
Do outsiders offer better value at SP?
A historical Betfair study found that BSP compared favourably with earlier exchange prices for many bigger-priced runners. That finding should not be treated as a universal rule for bookmaker SP.
What does beating SP mean?
Beating SP means taking odds longer than the horse’s eventual starting price. For example, backing a horse at 8/1 when it starts at 5/1.
Does beating SP mean a bet is profitable?
No. A strategy can regularly beat SP and still lose money if its selections win too infrequently relative to the odds taken.
What is the difference between SP and Betfair SP?
Industry SP is the official starting price derived from bookmaker market information. Betfair SP is calculated through the Betfair exchange mechanism. The two prices can differ substantially.
Does Best Odds Guaranteed make early prices better?
For qualifying bets, BOG can provide the larger of the early price and SP. However, eligibility and settlement rules vary, and the promotion does not guarantee a profitable bet.
Can a horse shorten and then drift again?
Yes. Historical research shows that an early shortening move does not necessarily continue through to SP. Prices can reverse direction as the market develops.
Should I always wait until just before the off?
No. Waiting can provide additional information, but the available odds may shorten. The best decision depends on the selection’s estimated winning chance and the price offered.
Are overnight prices better than morning prices?
There is insufficient consistent public evidence to establish a universal advantage. Overnight and morning prices should be tested separately using comparable historical data.
Is it better to compare bookmakers than wait for SP?
Comparing bookmakers can reveal different fixed prices available at the same time. Obtaining a stronger price may be useful, but it does not guarantee that the selection offers value or that the price will beat SP.
So, Are Early Prices Better Than Starting Price?
The available evidence does not support a simple rule that backing horses early always produces better value.
Historical UK Flat racing research found that more horses drifted than shortened between morning prices and the opening show.
Separate exchange-market research suggests that earlier prices can be more attractive for shorter-priced runners, while Betfair SP may compare more favourably for bigger outsiders.
These findings are useful, but they concern different markets and periods.
They do not establish a profitable betting strategy.
The most important distinction is between obtaining a bigger price and obtaining genuine value.
An early price can be excellent if the horse’s chance is underestimated and its odds subsequently shorten.
Waiting can be beneficial if the market offers a bigger price without a corresponding reduction in the horse’s chance.
Neither approach removes the need to assess the horse and the race.
For a serious betting analysis, the strongest method is to record selections and prices before the event, compare them with SP and evaluate the complete results over a meaningful sample.
The aim should be to make consistently sound decisions at the prices available, rather than assume that one particular time of day always offers the best odds.
Research Sources
The historical findings discussed in this feature come from the following publicly accessible research:
- Dave Renham, Steamers and Drifters: Part 3, Geegeez, 17 October 2023. https://www.geegeez.co.uk/steamers-and-drifters-part-3/
- Dave Renham, Early Odds to Opening Odds to Starting Price, Geegeez. https://www.geegeez.co.uk/early-odds-to-opening-odds-to-starting-price/
- Peter Ling and Mark Kemp, Comparing Betfair SP With Odds in the Live Betfair Market, Smart Betting Club, August 2020. https://smartbettingclub.com/wp-content/uploads/2023/05/Betfair-Racing-Market-Analysis.pdf
- Betfair, Starting Price Historical Data. https://promo.betfair.com/betfairsp/SP_history.html
The percentages and historical results attributed to these sources are published research findings. Worked betting examples are illustrative calculations, not actual race results.
