Best Odds Guaranteed, Rule 4, non-runners and dead heats

A horse-racing matched bet can change after you place it. Best Odds Guaranteed may improve the bookmaker return. A withdrawal may cut bookmaker winnings under Rule 4 and alter the matched exchange odds through a reduction factor. A dead heat can turn one apparent winner into part winner and part loser.

The useful habit is simple: treat the bookmaker and exchange as two separate settlements. Read each one, then rebuild the combined result from the figures actually used. Do not assume that one side's revised price will neatly cancel the other.

The short answer

Best Odds Guaranteed, or BOG, pays the better of an eligible early price and the Starting Price under that bookmaker's current terms. Rule 4 reduces the winnings on an affected fixed-odds bet when another horse is withdrawn. An exchange reduction factor adjusts matched bets after a non-runner, but it is a separate rule with its own percentage and calculation. A dead heat splits the stake or contract because there are more winners than the market expected.

None of those events automatically ruins a match. They do mean the original calculator screen is no longer the final account. Record the revised bookmaker return, revised exchange odds or liability, and any dead-heat fraction before deciding whether you have a profit, a qualifying loss or an open position.

What Best Odds Guaranteed changes

BOG concerns the bookmaker price. If an eligible horse wins and its Starting Price is bigger than the price you took, the bookmaker settles at the bigger price. It is a concession, not a permanent feature of every horse-racing bet.

Sky Bet's current help page, for example, limits BOG to eligible Sky Bet Club customers and qualifying win or each-way bets placed from 9am on race day before the start. Its exclusions include ante-post bets, extra-place races, price boosts and various specials. Those are Sky Bet's present terms, not a template you can paste over another operator.[1]

Check the race card and bet receipt before using BOG in a calculation. A logo saying "Best Odds Guaranteed" elsewhere on the site does not prove that your account, market, time or promotion qualifies. If the horse loses, there is no higher winning return to apply.

BOG can also interact with a withdrawal. Sky Bet says a taken price subject to Rule 4 will keep the deduction unless the horse returns at a bigger Starting Price, in which case the bet returns at that Starting Price without that Rule 4 deduction. The precise interaction is operator-specific, so the settled receipt beats a hand-built assumption.[1]

Rule 4 reduces profit, not the returned stake

Rule 4 applies to affected fixed-odds bets placed before a relevant horse was withdrawn. The deduction is quoted as pence in each pound of winnings. A 10p Rule 4 means 10% comes off the profit, while the original stake is returned in full if the bet wins.

The amount depends on the withdrawn horse's price at the time of withdrawal. Shorter-priced non-runners usually produce a larger deduction because removing them changes the remaining runners' chances more sharply. Sky Bet also states that several deductions can apply, capped there at 90p per £1, and confirms that the full stake remains outside the deduction unless dead-heat settlement also applies.[2]

Timing matters. A bet placed after the market has been reformed should use the new prices and is not hit by the earlier withdrawal's deduction. With several withdrawals, bets placed at different times can therefore settle differently even when they are on the same horse.

The exchange uses a reduction factor

The exchange side does not simply copy the bookmaker's Rule 4. It removes the non-runner, voids matched bets on that horse where its rules say so, and may adjust existing matched prices on the remaining runners.

Smarkets describes its reduction factor as the exchange equivalent of Rule 4. In a win market, a non-runner below its 2.5% threshold leaves other bets unchanged. At 2.5% or more, matched bets are adjusted, unmatched bets are cancelled and the market reopens. Its worked rule says odds of 4.0 subject to a 25% reduction become 3.0.[3]

That cancellation point is easy to miss. An unmatched lay is not protection. After a withdrawal, confirm that the required lay still exists, note the revised matched odds and check the new liability. Do not place a fresh full lay merely because the old price vanished from the screen. Part or all of the original bet may already be matched and adjusted.

Worked example: one withdrawal, two calculations

Suppose you back a horse with £20 at 5.0 and lay it at 5.2 with 2% exchange commission. These figures are hypothetical. The balanced lay stake, rounded to the nearest penny, is:

£20 × 5.0 ÷ (5.2 − 0.02) = £19.31

The original exchange liability is £19.31 × 4.2 = £81.10. The result is a £1.10 loss if the bookmaker bet wins or a £1.08 loss if it loses.

Now assume another horse is withdrawn and, purely for this example, the bookmaker records a 10p Rule 4 while the exchange applies a 10% reduction factor. Do not assume real percentages will match. The bookmaker profit falls from £80 to £72. The exchange odds fall from 5.2 to 4.68, making the revised liability £71.06.

If the selection loses in the first two rows, the lay wins £18.92 after 2% commission and the combined result is about −£1.08. The BOG row shows why a drift can create an upside when the operator's terms pay the larger Starting Price. It is not a promised result. Eligibility, the actual SP, the recorded Rule 4 and the exchange reduction all have to be checked.

What if your own horse is the non-runner?

First identify the market. Day-of-race, non-runner-money-back and ante-post bets are not interchangeable.

On Smarkets, a withdrawn runner is removed and bets on it are voided in the ordinary market covered by its horse-racing rules. Its ante-post rule is different: bets stand whether the horse runs or not unless it is balloted out, and reduction factors do not apply to those ante-post markets.[3]

A bookmaker may also refund an eligible day-of-race non-runner while treating an ante-post selection as a loser, unless a stated non-runner-no-bet concession applies. Read the market label rather than relying on the race date alone.

If both your back and lay are voided, the position usually disappears. If only one side is void, or you used unlike markets, you may still have exposure. This is why the selection name, market type and place terms belong in your tracker, not just the odds.

A dead heat is part win and part loss

When two horses dead-heat for one winning place, a conventional bookmaker applies half the stake at the full odds and treats the other half as lost. Exchanges split the winning and losing portions too. Smarkets states that dead-heat winnings and losses are divided by the number of competitors and publishes separate equations for back and lay contracts.[4]

Use the original £20 back at 5.0 and £19.31 lay at 5.2. In a two-way dead heat for first:

• The bookmaker returns £10 × 5.0 = £50. Against the original £20 stake, that is a £30 profit.
• The exchange lay loses £30.90 after splitting the lay contract into winning and losing halves.
• The combined result is a 90p loss before any other market-level commission adjustment.

That is close to the ordinary balanced result, but do not generalise from one example. Three-way ties, each-way place dead heats and markets with several expected winners use different fractions. Rule 4 can apply as well as dead-heat rules, so copy the settled figures from both accounts.

The six checks to make before moving on

1. Confirm the market. Check win, each-way, place, extra-place, ante-post or non-runner-no-bet on both sides.
2. Read the bookmaker receipt. Note the final odds, Rule 4 amount, BOG price and returned stake.
3. Read the exchange statement. Note void bets, reduction factor, revised matched odds, cancelled unmatched money and final liability.
4. Handle any tie. Record the number of joint winners and the number of places available.
5. Recalculate from settlement. Add bookmaker profit or loss to exchange profit or loss. Use the account figures, not a screenshot taken before the withdrawal.
6. Save the evidence. Keep the bet IDs and settlement notes until both balances agree with your tracker.

If a market is still suspended or unsettled, wait. Guessing the reduction and adding a second lay can turn a routine adjustment into a real duplicate bet.

For promotion-specific calculations, use the separate guides to horse-racing refunds and extra-place offers. Both need more outcomes than an ordinary win-only match.

Use the tool, then check the receipt

An oddsmatcher and calculator are useful for choosing the original back and lay. Racing tools can also flag BOG opportunities. They cannot decide which account-specific concession applied after the race or read a late settlement note for you.

Outplayed brings the offer instructions, oddsmatching and calculators into one workflow. Use that to prepare the bet, then reconcile the bookmaker and exchange statements yourself whenever there is a non-runner or dead heat.

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