How to identify value in your bets? That’s the big question. My friend, Alex Napier who operates the Best Bet Soccer website, has asked me to write this article to explain how bookmakers’ percentages are calculated and how they provide a guide to assessment of value in the odds on offer. He has asked me to look at soccer betting, where, due to the few possible outcomes (three choices – win, lose or draw) the odds offered are short in any event.

What I’ll show you is:

1. how to calculate the bookmakers percentages;

2. what these percentages tell us;

3. how to assess value in the odds;

4. how to allocate your stake.

How to calculate the bookmakers’ percentages

The following data are taken from a Europa League qualifying match in July 2009 between Bangor City v Honka. The two bookmakers selected are the two that offered the best price for the draw:

Bookmaker 1

· Home win 4/1 – 20.00%;

· Draw 11/4 – 26.67%;

· Away win 8/15 – 65.22%;

· Total – 111.89%.

Bookmaker 2

· Home win 11/4 – 26.67%;

· Draw 11/4 – 26.67%;

· Away win 8/11 – 57.89%;

· Total – 111.23%

Best odds

· Home win 4/1 – 20.00%;

· Draw 11/4 – 26.67%;

· Away win 8/11 – 57.89%;

· Total – 104.56%

To calculate the percentages divide 100 by the odds on offer plus one. Where the odds are A/B: 100/((A+B)/B). For example, 4/1 is 100/((4+1)/1) or 20.00%. For 11/ 4 the percentage is 100/((11+4)/4) =26.67%. For 5 – 2 what would the percentage be? 100/((5+2)/2)=28.57%.

What these percentages tell us

A perfectly “balanced book” where the singapore pools soccer odds offered exactly reflect the chance of each team winning or the draw would produce a total of 100.00%. Theoretically the bookmaker will profit by the total percentage on the match less 100.00%. In the above table bookmaker 1 should profit by 11.89% of turnover on the match and bookmaker 2 by 11.23%. At first sight there doesn’t seem to be much between them but when we compare the theoretical profit of each the margin on the bookmaker 1 odds (i.e. 111.89 – 100.00 = 11.89%) is 5.84% higher than the 11.23% margin on the bookmaker 2 odds! Where the odds on offer produce a theoretical profit for the bookmaker the book is said to be “over round”. The bookmaker 1 book is over round by 11.89% and the bookmaker 2 book by 11.23%.

Where the odds on offer total less than 100.00%, which never actually occurs with the odds offered by any individual bookmaker as they’d in theory be certain to lose on the event, they are “under round”. The losing percentage would be 100.00% less the total odds percentage. Not surprisingly this doesn’t happen. Individual bookmakers do not offer odds on the possible outcomes that would give them a loss. What does happen, although very infrequently, is that the odds offered by a selection of bookmakers may vary to the extent that you can find a combination where those for the three possible outcomes are under round. This means that you can bet on all three possibilities – win, lose and draw – and provided you allocate your total stake in the correct proportion you will make a profit of the percentage by which you can bet at under round odds.

Identifying value

From the above data it’s fairly obvious that the 4 – 1 offered by bookmaker 1 in respect of the home team winning is the best price, there is no difference in the odds offered for the draw but bookmaker 2 offers the best odds for the away win. The question then arises, which is the best value? Obviously the 20.00% offered by bookmaker 1 on the home win is the lowest percentage so could be the best value, but this is too simplistic. There has to be a yardstick to measure the odds against. That is your own assessment or your advised assessment of the chance of each outcome. If you give each possibility your own percentage rating you can compare this with the bookmaker odds percentage to establish where the value lies. How you assess the chances of each outcome is not for this article. It deserves more in depth treatment than can be given here where we are dealing with bookmakers’ margins and value bets.

Assuming that the true reflection of the chances on the above match were home win 20% (bookmaker 1 had that about right and bookmaker 2 was under priced), a 20% chance of a draw (although these were the bookmakers offering the best odds on the draw they were still under priced) and a 60% chance of an away win (where bookmaker 2 quotes a price that gives a lower percentage chance so offers value) consideration should be given to an away win bet with bookmaker 2.

Stake allocation

There may be occasions when it is necessary to allocate your stake between different outcomes. This could be the case where a selection of bookmakers odds produce an under round opportunity or where there is a strong reason to include two of the three possible outcomes so it’s necessary to allocate the stake between them. In the illustration below the odds have been exaggerated. It’s very seldom in reality that an under round opportunity arises but the illustration is a good one to show how to use percentages.

Bookmaker 1

· Home win 5/1 – 16.67%;

· Draw 11/4 – 26.67%;

· Away win – 66.67%;

· Total – 110.01%;

· Combined draw and away win – 96.34%.

Bookmaker 2

· Home win 7/2 – 22.22%;

· Draw 5/2% – 28.57;

· Away win 4/6 – 60.00%;

· Total – 110.79%;

· Combined draw and away win – 88.57%.

Bookmaker 3

· Home win 7/2 – 22.22%;

· Draw 4/1 – 20.00%;

· Away win 4/9 – 69.23%;

· Total – 111.45%;

· Combined draw and away win – 89.23%.

Best odds

· Home win 5/1 – 16.67%;

· Draw 4/1 – 20.00%;

· Away win 4/6 – 60.00%;

· Total – 96.67%;

· Combined draw and away win – 80.00%.

Bookmaker 1 offers the best price for the home win, bookmaker 2 for the away win and bookmaker 3 for the draw. The combined odds of the best offers (5-1, 4-1 and 4-6) produce an overall 96.67%. That’s under round by 3.33%. If you stake 16.67 units on the home win at 5-1 with bookmaker 1 the return for the win would be 100.00 units, 60.00 units stake with bookmaker 2 on the away win would also return 100.00 units for the win and 20.00 units with bookmaker 3 on the draw would return 100.00 units for the draw. For every 96.67 units you stake split in that way you’d receive a return of 100.00 units. It doesn’t seem much but where else can you get this sort of return on your money invested for less than a day?

A word of warning though.

Where this situation arises there can be heavy, high stake betting. This results in the bookmakers changing the odds they offer. You therefore need to take great care that you place all of your bets at the identified under round odds. This means checking the relevant bookmakers’ accounts simultaneously. Open them up in separate windows on your screen, complete your betting slip for each and when you begin placing the bets complete the process as quickly as possible. There’s no guarantee that any of the bets will not be refused as the odds may have changed after you completed the slip so there is an element of risk but you can minimise this if you streamline the way you place the bets.

What may be more useful is the assessment of the percentages for the two most likely outcomes.

For instance, if both teams are strong defensively although the away win is the probable result the draw may be considered to be a distinct possibility. If you (in your own assessment) totally discount the likelihood of the home win ( as the odds in the illustration more or less do) you may wish to bet on both the away win and the draw.

The best odds for the away win are the 4/6 (60.00%) offered by bookmaker 2 and the best for the draw the 4/1 (20.00%) offered by bookmaker 3. So if you stake 60 units on the away win with bookmaker 2 and 20 units on the draw with bookmaker 3 provided the home team don’t win you’d have a100 unit return for a 20 unit profit.

You need to use your own judgement to determine if there’s any value in the bet by comparing with your own assessment of the likely outcome of the match but it’s this analysis of the percentages against that assessment and then covering yourself with the second most likely possibility that, although it may reduce the profit on an event by event basis can lead to higher overall winnings in the longer term.


It is generally obvious which bookmaker is or bookmakers are offering the best odds. All you need do is compare them. Identifying value is another matter. For this you need to calculate the odds percentages to compare with your own, or your advised, perception or assessment of the chances of each outcome. By comparing the available percentages with your assessment you can identify where the value lies and make your selections accordingly – and perhaps now and again identify a no lose position where a selection of the odds offered by the various bookmakers produce an under round position! Disciplined use of percentages should form a major part of your strategy in identifying value in the odds offered and contributing to your betting profits.

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