Correcting Mistakes

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However careful you are, sooner or later you will make some sort of mistake when matched betting or arbing. The aim of this post is to help you to correct it for minimum loss.

When you discover you have made a mistake, particularly if you were placing a large bet, its a horrible feeling. The most important thing to remember is DON’T PANIC. While most mistakes will unfortunately result in a loss, very few are as bad as you imagine apart from those that you don’ t notice until you are checking your bets after the event. You should therefore try to check each bet carefully as you place it, particularly the receipt at the bookie, preferably taking a screenshot.

Bookie bets can not usually be changed (although you can always try phoning), so in most cases the easiest way to fix mistakes is at Betfair. Use the “what if” figures to calculate your position for various stakes until you find the best solution.







Screenshot showing “what if” figures on Betfair.

If you don’t have these enabled on your Betfair account, get them. Go into “More Options” on any Betfair market (underneath the “refresh” button), and make sure that both “Show Profit and Loss” and “Display “what if” figure” are ticked in the first left hand section, “Profit and Loss display”. You will then find that when you load a betslip and enter your stake, the green and red figures appear under all the selection names. These are what would happen if you placed the bet. When you do place the bet the p&l figures are shown every time you visit the market. If you load another betslip the figures remain, with the little arrows and a second set of figures showing the revised position if you were to place the bet. All very useful.

The most common cause of mistakes is being in a hurry.

General Strategy

1. Don’t Panic.

2. Your position at the bookie is probably inflexible. Work out what you stand to win or lose there.

3. Your position at Betfair is very flexible. Protect your bookie stake first – lay what you have backed, on the correct selection, for a loss if necessary.

4. Sort out your mistake at Betfair.

For any mistake at Betfair, you need to cancel the incorrect bet by submitting an opposite bet, and you can use the what if figures to help you. This applies to backing instead of laying, laying the wrong horse, laying on the wrong market, laying the wrong amount of money etc.

Examples of Common Mistakes

For ease of writing I shall refer in all cases to bets as being on a “horse”, but they could as easily be on a football team or anything else. Its just easier to write “horse”.

1. The bet wasn’t confirmed at the bookie.

This is surprisingly easy to do. Many bookies have confirmation screens that look very like the receipt, which is why you should always double check the receipt. Look for a transaction ID and the words “bet placed”. If you didn’t confirm the bet and don’t notice, it will simply not appear on your statement and there is nothing you can do.

So, you are in a hurry to grab an arb, you place the bet, place your lay bet and glance back at the bookie screen. You realise that you are still looking at the confirmation screen, not the receipt, and when you try to confirm the bet the odds have been cut. You have a lay at Betfair and no back bet.

Fix – easy – simply place a back bet at Betfair, using the what if figures to even out the result. With arbs you may well find that the price has drifted a little and you can take the same odds that you laid, or even trade out for a profit, but if the bookie has cut it is inadvisable to queue as the price at Betfair may well drop and make your position worse. As you gain more experience you will learn how to judge whether to queue or not, but often it isn’t worth the time and worry.

2. Backing at Betfair instead of laying.

Its not just novice Betfair users that do this – if you have been used to using trading software and want to queue for a price, this mistake is ridiculously easy to make.

Fix – Lay the same amount at the same odds, or use the what if figures to even out your position at different odds. Add what you originally intended to lay to match out your bet in the first place.

3. Laying the wrong amount of money at Betfair.

It is extremely easy to hit a key twice by mistake, or miss out a decimal point (I once laid £552 instead of £52, which resulted in a huge and very scary red figure). Sometimes this sort of thing results in a partly unmatched bet, which you can cancel straight away, then simply subtract what you intended to do from what you did and back the difference.

It is also quite easy to back the wrong amount at the bookie. Gamebookers, Partybets and occasionally Coral have a habit of missing a “0? off the end of your stake. Others may do this too – you can see it on the confirm screen and go back and change it. Always look carefully at the confirmation screen before pressing go, as some bookies (again Coral is a prime candidate) can cut the odds without making it terribly obvious. It takes far less time and effort to double check than it does to correct a mistake when the bet has gone through. If you do find you have backed £5 instead of £50 and laid £50, simply back the difference at Betfair. Annoying but not a disaster.

4. Laying the wrong horse.

One of the commonest arbing mistakes. You’ve found an arb, checked the arb and its good. You back the horse at the bookie, lay at Betfair and find that you have laid the wrong horse because there were 2 at the same or similar prices.

Fix – easy. Simply lay again on the correct horse, then submit a back bet at Betfair on the one you took by mistake.

5. Backed the wrong horse at the bookie (whether or not you have laid)

Most bookies do not have much sympathy with you if you back the wrong thing, and it is remarkably easy to do, particularly in markets with 2 selections at the same price. If it is looking really nasty you can try phoning them but don’t be surprised if they simply say “tough”.

Fix – Usually it is best to shrug and take a loss, which simply means getting out your spreadsheet and working out what the correct match is. In a 2-way market you may find it is better to dutch with another bookie than lay the mistake at Betfair (spreadsheet below). The alternative, if it looks as though the odds at Betfair might shorten, is to queue in the hope of getting matched at a better price. You have to be prepared to lose though – all queuing has an element of gambling, and if you let the bet go in running you must be prepared to lose the lot. As far as the lay part goes, if you have already laid you can cancel it out as in 1. above, or try to find another bookie with the odds you intended to back. Never back both outcomes in a 2-outcome event at the same bookie if you have backed the wrong one in error.

6. There’s a rule 4 you didn’t notice or the bookie cut the odds and you didn’t notice.

You are left with something that quite definitely isn’t an arb. If you have already laid you need to use your spreadsheet to work out what the correct lay should be, and back the difference at Betfair. This will result in a loss, but not as big a loss as if you leave it and the horse wins. Of course, if it loses you would be fine to leave it alone, but that is gambling. In general the higher the odds, the bigger the damage. There are instructions on what to do if a horse is withdrawn after you bet but before you lay in this post.

If you have not yet laid and you realise you have backed at the wrong odds, you can either match out for a loss at the available odds or decide to queue for better ones. This will depend very much on your temperament as well as how much time there is before the race, how much money is available to lay and how active the market is. If you are the sort of person who doesn’t mind a small gamble but you don’t wnat to risk your whole stake by queuing, you might like to try a strategy I sometimes used when arbing at board price, if the price suddenly drifted (see below), if you like to close off a bet and move on then just match out for a loss both ways.

7. The odds at Betfair drifted just after you bet at the bookie.

This again leaves you with something that isn’t an arb. You can take what is available for a loss, queue your whole stake for lower odds in the hope it comes back down (which it might not), or try my strategy below. If the odds are moving fast it is sometimes better to sling in an approximate amount to protect the majority of your stake and sort out the details afterwards.

My “halfway house” strategy

WARNING – there is absolutely no guarantee that any bet you try to match in running will get matched. You must be prepared to lose anything you leave to go in play.

I would only ever do this if I was betting near to the off on a market going in play and on a horse which was a reasonably short price. Trying to match high priced horses in running is not a very good idea.

I absolutely DO NOT advocate using anything resembling this strategy to try to create an arb that is not there. This is for rescuing mistakes and drifters only.

Something I sometimes do if I have a bet at a bookie on a horse that I can’t then easily arb (because its the wrong horse or the original lay money has gone and the price has drifted etc) is to lay some of the money at the current price and put the rest in running at a shorter price, using the “what if” figure. I would only ever do this if I had reasonable grounds to think it was likely that the horse would shorten in running (eg a strongly backed horse is probably fancied to win).


A horse is priced at 2.5 at the bookies and 2.4 at Betfair, so I bet £50, but before I can lay the price shoots out to 2.5. Rather than take a small loss, I decide to queue at 2.4, but the price continues to lengthen. I decide that it is unlikely to come down much before the start, so I lay £40 at 2.54. This has immediately cut my potential losses down from £50 to about £12 depending on commission rate. I know that my back bet will win me £75 if it wins, and my current lay loses £61.60 at 2.54, so I have £13.40 to “play with”. If my commission is 5% I need to lay another £12.63 to make no loss if the horse loses, and if I play with the odds in the betslip and use the “what if” figures I find that the maximum price I can lay this at without loss is 2.06. I can do this before the race starts by placing the bet in the queue and selecting the “keep bets” option on the unmatched betslip and resubmitting the bet. This ensures that the bet is not cancelled when the market suspends and goes in play.







Select the keep bets option and resubmit the bet.

Remember that if you go in running you are gambling that the price will shorten this much, and you will lose your £12.63 if it doesn’t. The more of your stake you lay beforehand, the shorter will be the price you need to reach in running. I find this more acceptable than taking a guaranteed loss on a short priced favourite and then watching the thing win, but plenty of professional arbers strongly disagree with me!

8. You think you have an arb, but then find you’ve backed and laid different markets.

Bookies sometimes confuse you by calling things different names, eg double result and half time/full time are not usually the same, but are confusingly close. Do not assume that because something appears on an odds comparison site it is correct – I have seen match odds compared with half time odds and all sorts of other permutations. Check for yourself especially if you are clicking through from the odds comparison site rather than navigating to the market yourself on Betfair. Big arbs can be a warning that something is not quite right.

There are 2 scenarios here – a) there’s a market for both at Betfair, and b) you’ve bet on something that can’t be matched at Betfair (eg a handicap bet instead of an asian).

a). If there is a market for your bet at Betfair simply cancel out the incorrect lay as best you can by backing, and lay on the correct market. You will almost always have to take a loss in these circumstances.

b) If there is no market on Betfair you will have to look elsewhere. The obvious places are other exchanges – try Betdaq and Betsson. If it is a 2-way market you may find it easier to dutch with another bookie – this is particularly true for tennis if you have backed somewhere which has the wrong rules. For football match odds the Asian handicap is your friend, as you can safely do a 2 way dutch if you have backed team A by backing team B on the +0.5 Asian (the half handicap rules out the possibility of a draw). Use the dutching spreadsheet (below) to work out your stakes, but remember that bookies are suspicious of weird stakes so it is safest to round up or down to the nearest £.

Sometimes it just isn’t possible to fix it and you have to sit and suffer. Don’t be tempted to match it off against something vaguely similar in the hope that it works out – usually all this does is increase your potential losses.

9. You go for an arb and the Betfair market suspends as you try to lay. Its not in play.

We’ve all done it – just before kickoff is the time when the odds move most and tempting arbs can appear. ALWAYS take a moment to check the start time – bookies can void bets that were placed after the official start time. This is less likely in tennis, where matches can be delayed due to weather and start times are approximate, but if in doubt, leave it.

This is very similar to the situation above where there is no market on Betfair. Some bookies have in play markets for football and other sports and you can dutch against those. Bet365 is a good place to start looking, if you can bet there. Be very careful with Asians and handicap bets if there has already been a goal – at some bookies some of these have a rolling scoreline and you are betting that there will be another goal, not on the current score.

Again there will be times when you just have to sit and hope, and learn to be more careful in future.

Dutching Calculator – 2-way-dutching.

Our AI articles are NOT written by a real person and are provided for entertainment only. They may contain content which is inaccurate but we are hoping our AI bot, Rose, will become better over time. The AI category is the ONLY section of that has zero human input.

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