Best Odds Guaranteed Explained: How BOG Pays in Horse Racing

Best Odds Guaranteed, usually shortened to BOG, is a settlement concession offered by many UK and Irish bookmakers on horse racing. You take a fixed price before the race. If your horse wins and its starting price (SP) turns out bigger than the price you took, you are paid at the SP instead. If the SP is smaller, you keep the price you took. Either way, you get the better of the two.

On a single race that looks like a small courtesy. Over a season it matters, because it removes the main risk of betting early: watching your horse drift and win at a bigger price than you got. Below are worked examples, each-way and Rule 4 settlement under BOG, the conditions that differ between bookmakers, and the value maths.

How Best Odds Guaranteed works

Prices move from the morning onwards, and at the off the official starting price is returned for each horse, based on the on-course market. Without BOG, you choose on the bet slip between a fixed price you can see now and SP, which you only learn once the race starts. Our horse racing betting guide covers that choice in more detail.

BOG merges the two for winning bets. You take the fixed price, and when the bet is settled the bookmaker compares it with the SP and pays whichever is bigger. Nothing changes for a losing bet: a beaten horse loses your stake whatever its price was.

Three points trip up beginners. BOG only matters if you take a fixed price; an SP bet has nothing to compare. The comparison uses the official SP, not the last price on a website. And BOG is a bookmaker term, not a racing rule, so it applies only where offered, on the races and bet types the bookmaker names.

Worked examples: early price against SP

You back a horse at 5/1 (6.00 in decimal) with a £10 win bet at 10am. The horse wins. What you get back depends on where the SP lands:

• SP 7/1 (8.00): the horse drifted. Without BOG you receive £60, your £50 profit plus the £10 stake. With BOG you are paid at 7/1 and receive £80, a £70 profit. BOG is worth £20 here.
• SP 5/1 (6.00): the price did not move. You receive £60 with or without BOG.
• SP 4/1 (5.00): the horse shortened. An SP bet would return £50, but you took 5/1, so you receive £60. BOG plays no part, because the price you took was already the better one.

The same logic works in decimal. Say you put £20 on a horse at 11/4, which is 3.75 in decimal. At the price taken, a win returns £20 x 3.75 = £75. If the horse goes off at 9/2 (5.50), BOG settles the bet at 5.50 and you receive £110, an extra £35 for doing nothing.

Each-way bets under BOG

Where a bookmaker applies BOG to each-way bets, the bigger price is used for both halves. The place part is still paid at the place fraction, so a bigger win price also means bigger place odds.

Worked example: £5 each-way at 8/1 (9.00) in a race paying 1/5 the odds for three places, so £10 in total. The horse goes off at 12/1 (13.00).

• It finishes second or third. At the price taken, the place odds are 8/5 and the place part returns £13. Under BOG the place odds become 12/5 and the place part returns £17. The win part loses either way.
• It wins. At the price taken you would receive £45 from the win part and £13 from the place part, £58 in total. Under BOG you receive £65 plus £17, £82 in total.

The placed-only line matters most, because outsiders place far more often than they win. Place terms vary by bookmaker and race; see our guide to each-way bets. To check a return before you bet, run both prices through the each-way calculator.

How Rule 4 deductions interact with BOG

When a horse is withdrawn after you have taken a price, Rule 4 deducts a set amount from winnings on fixed-price bets, based on the withdrawn horse's price when it came out. The tables are in our explainer on Rule 4 deductions.

BOG does not cancel a Rule 4 deduction. A common approach in bookmaker terms is to apply the deduction to the price you took first, then compare that reduced price with the SP and pay whichever is bigger. The SP itself is normally not reduced when the market had time to re-form after the withdrawal, because the starting prices already reflect the smaller field. If the withdrawal came too late for that, the SP can carry a deduction as well.

Worked example: £10 win at 6/1. A well-fancied rival is withdrawn and the table gives a deduction of 20p in the pound. Your horse wins.

• Without BOG: your £60 of winnings lose 20%, which leaves £48, and you receive £58. In effect, 6/1 has become 4.8/1.
• With BOG and an SP of 7/1, formed after the market re-formed: 7/1 is bigger than 4.8/1, so you are paid at 7/1 and receive £80.
• With BOG and an SP of 9/2: 4.5/1 is smaller than 4.8/1, so the deducted early price stands and you receive £58.

Bookmakers word this part of their rules differently, so read the BOG terms of the one you use instead of assuming the order of calculation.

Conditions that vary from one bookmaker to another

There is no industry standard for Best Odds Guaranteed. Each bookmaker writes its own terms, and they change. Treat these as points to check on the terms page, not as rules that apply everywhere:

• Which races are covered: usually UK and Irish racing only. Racing in other countries, and some specific races or meetings, may be left out.
• When it starts: BOG is often available only from a set time on the morning of the race. Ante-post bets placed days or weeks earlier are generally excluded.
• Bet types: it may apply to win and each-way singles but not to some multiples, full-cover bets or forecasts and tricasts. Pool bets such as the Tote are settled from the pool and sit outside BOG.
• Caps: some bookmakers limit the extra amount BOG can add to a bet or to an account over a period.
• Free bets and boosted prices: bets placed with bonus funds, or at an enhanced price, are often excluded.
• Account restrictions: a bookmaker can remove BOG from an individual account, typically one it sees as consistently beating its prices, while still advertising it to everyone else.

If you bet in multiples, check how BOG is applied to each leg. Lucky 15s and other full-cover bets are a common exclusion, and the full-cover bets guide explains how those bets are built.

The value maths: why an early price with BOG is a free option

Without BOG, an early price is a trade: you win if the horse shortens and lose out if it drifts. With BOG, you keep the first and lose the second. That is an option, a right to the better outcome that costs nothing to hold. A simple expected-value illustration shows what it is worth. You back a horse at 5/1 with £10. You estimate its true chance at 16%, a little under the 16.7% the price implies, so on its own the bet has a small negative expectation:

0.16 x £50 profit, minus 0.84 x £10 lost, equals £8.00 minus £8.40, which is minus £0.40 per bet.

Now add BOG. Suppose this kind of horse drifts to 7/1 by the off one time in four, and keep the 16% winning chance for simplicity. When it drifts and wins, BOG adds £20 of extra profit. The expected gain is 0.25 x 0.16 x £20 = £0.80 per bet, which turns minus £0.40 into plus £0.40. Over 100 such bets, that is the difference between expecting to lose £40 and expecting to win £40.

Treat that as an illustration, not a forecast. Horses that drift tend to win a little less often than the morning price suggested, so the true gain is smaller. The direction holds, though: BOG can only add to an early bet, never make it worse. See also value betting and closing line value; beating the SP is racing's version of beating the closing line.

When BOG does not help

BOG pays nothing when your horse shortens. If you took 5/1 and it goes off at 3/1, you are paid at 5/1, which is what a fixed price would have given you anyway. Here the value came from your judgement in taking the early price, not from the concession. BOG also adds nothing to a losing bet, nothing when the race falls outside the terms, and nothing if the bookmaker has withdrawn it from your account. If you only ever take SP, it is irrelevant to you.

BOG compared with SP betting and betting exchanges

Taking SP means accepting whatever the final price is. An early price with BOG pays at least SP on a winner, plus a better price if the horse shortens, so where BOG is on offer a straight SP bet rarely makes more sense.

Betting exchanges work differently. You bet against other customers, the exchange charges commission on net winnings, and there is no BOG: the price you are matched at is the price you get. Exchanges also run their own starting price, calculated from bets matched at the off, which is often bigger than the industry SP before commission. On a horse that drifts, an exchange bet matched early can end up worse than a bookmaker bet with BOG. On a horse that shortens, a big early exchange price can beat both.

Before you take an early price

A short routine makes sure BOG works the way you expect:

• Check that the race is covered and that the bet is placed after the BOG start time.
• Make sure the slip shows a fixed price, not SP, since BOG only compares a fixed price with SP.
• Confirm that the bet type is eligible, especially for each-way multiples and full-cover bets.
• Read the terms on caps, free bets and boosted prices.
• After a non-runner, check the settlement against the Rule 4 table and the BOG terms.
• Look at the account settlement after the race and query anything that does not match the SP.

BOG improves the price on bets you were going to make. It is not a reason to bet on more races. Betting laws differ by country and, in some places, by state or region, so check the law where you live and use licensed operators only. Set a budget before the first race, never raise stakes to win back losses, and see our responsible gambling page for limit tools and support services.