Value bets

Bookmaker odds are determined by the bets placed by the bookmaker’s customers. As more people bet on a given outcome, the bookmaker will adjust the odds in order to hedge its position and earn a margin. From these odds, we can estimate the probability distribution of event outcomes. Although bookmaker odds are determined by betting patterns, they are usually representative of the probabilities of event outcomes. This is due to a statistical phenomenon called the “wisdom of the crowd” – the bias of individual bettors averages out, giving a reasonable end result.

To find our picks, we look at the odds quoted by multiple bookmakers. We then identify outliers that fall outside the 95% confidence interval for the “ideal odds”, calculated as +/- two standard deviations from the mean of all quoted odds. This way, we identify bookmakers who, for some reason, represent a significantly different view on the probability distribution of a given event outcome.

We then calculate the implied event outcome probability for the inlier odds (those within the confidence interval, or in other words, the ones who have a more or less common view on the event’s outcome probability). When calculating these probabilities, we remove the margin in proportion to the odds, which is a recognized best practice.

Finally, we calculate the expected value of the potential win of placing a bet with the bookmaker who is quoting outlier odds as:

outlier odds × average implied probability from the inlier odds

For example, placing a €1 bet on outlier odds of 2.0, when the average implied probability from the inlier odds is equal to 60%, you can expect to earn a net profit of €0.2 (or 20%) over your initial investment:

€1 × 2.0 × 60% - €1 = €0.2

This approach has many benefits:

- it’s based on a sound mathematical framework and not your trust in someone’s predictions;
- you can make informed bets without having to factor any of your expectations into the formula, choosing bets with an expected profit and the probability of winning that satisfy your individual strategy;
- by taking the average implied probability of the inlier odds, we strengthen the effect of the “wisdom of the crowd”.

While no bet is certain, sticking to bets with positive expected value will likely result in a net win over time. For more information on value betting, bookmaker odds, expected value, and variance in betting, visit our article section.

Bet tool

The purpose of the tool is to identify profitable sports bets with ease. All you have to do is:

- choose an event from our database of bookmakers’ odds or add a custom one;
- set the probabilities of the event outcomes to your best knowledge using the intuitive sliders.

Based on the probability distribution you specify, the tool will highlight the profitable odds in green and calculate the expected profits on your picks.

The tool handles single, double and multiple bets. By adding custom events you can analyse any bookmakers’ odds and less vanilla-type bets such as handicaps or over-under.

The tool is regularly updated with bookmakers’ odds for the most popular sports. You can specify your prefered bookmaker using the dropdown list under the events database.

If you would like to learn more about the scientific framework for sports betting, you can refer to our articles section. If you would like to start using the tool, you can read the manual below or – as we believe the tool to be very intuitive – just start using it.

You do not have to register to use the tool, but your coupon will be limited to 12 events and the data will be deleted after 48 hours; it might also be lost, e.g. when your browser closes. You can register using the *Login* button in the top navigation bar – no private data such as your email address is required.

The tool is located under the *Bet tool* tab in the top navigation bar and allows you to analyse the expected value of odds in two steps:

- First you have to add some events to your coupon using the
*Events* database which contains predefined events or by adding a custom event using the *Add event* tab in the top navigation bar.
- Events on your coupon are represented by flashcards. Use the sliders on the flashcard to specify a probability distribution for the outcomes. Odds with a positive expected value will be highlighted in green.

Once you specify your picks using the checkboxes on the flashcard, the expected net profit of a €10 bet on the event, together with the odds and probability of a payout, will be presented both on the flashcard and, for a multiple bet composed of all the active events on your coupon, below the flashcards.

The odds provided in the *Events* database are refreshed approximately once every half an hour. You can specify your preferred bookmaker using the *Bookie* dropdown list under the *Event database*. If these odds are not available or you do not specify a bookmaker, the highest odds across all bookmakers will be used in the flashcards.

The net expected profit of your bets is calculated using the formula:

€10 × your odds × probability of a payout - €10

Below is an example coupon shown before and after picking some outcomes. As you can see, thanks to the *Add event* functionality you are able to analyse less vanilla bets by e.g. assigning the odds of ‘over 2.5 goals’ to outcome 1 and the odds of ‘below 2.5 goals’ to outcome 2. Double chance odds are supported by default.

- We hid the
*Events* database to gain more workspace;
- We changed the outcome probabilities for all events, after which the profitable odds automatically became green;
- We picked the outcomes we are potentially interested in betting on, including a double chance bet for the first event, so each flashcard shows statistics for a €10 bet on our picks;
- We deactivated the second event by pressing the monkey icon (🐵), so it is not included in the multiple bet statistics.

The coupon before making the picks

The coupon after making the picks

If you are unhappy with your picks for a specific event, you can press the refresh button (♻️) to reset the data for this event to the default values.

For events added from the sidebar, you can analyse all odds available in the tool by pressing the magnifying glass icon (🔍).

If you are no longer interested in an event, you can remove it from your coupon by pressing the bin icon (🗑️).

Vintage events are not archived in the app’s database – an event flashcard will be deleted 24 hours after the event starts.

- If you register or log in after you add some events to your coupon as an anonymous user, the events will be moved to your user account on login.
- Sometimes odds can be marked as profitable before you change the outcome probabilities, like for the first event in the manual above. This is not a data error. Firstly, if you use the best odds across all bookmakers, this is an indicator of a possible arbitrage opprotunity. Secondly, as the probabilities implied from odds are rounded, a possible 1% rounding error could make some odds (barely) profitable.
- When calculating the initial probabilites from the odds, we assume most of the bookmakers’ margin was allocated to the highest odds.
- When adding a custom event you only have to provide the event name and odds. If you want to add odds for a sports event where the game doesn’t end in a draw (e.g. basketball), leave the
*Odds x* section blank.
- You do not have to bet on all the events on your coupon – events left out will simply not be part of the calculated statistics.
- We recommend reading our articles on sports betting. You will find them under the
*Articles* tab in the top navigation bar.