Can a bookmakers’ odds vary?

It’s a pretty simple question to answer. Knowing what are “odds” and what exactly “bookmakers” do is essential to understand the question. By answering both of them, we can conclude that a bookmakers’ odds can vary.

Starting by: What is a bookmaker? It’s an entity that regulates and monitors odds through a totally legalized platform. Its customers can bet in specific odds and certain sport events. These bets can be placed throughout the event or even before it begins.

What are odds? Odds are basically probabilities. However, its true definition is the inverse of the probability of an event. Let’s suppose we toss a coin, there is 50% probability of getting heads or tails, the odd for that event is of 2.00. That way, betting £10 in a 2.00 odd, my potential profit if I bet on heads and I win would be £20.

There are several odd formats, but these ones are the main ones and the most used:

• Decimal odds (European odds);
• Fractional odds (British odds);
• Moneyline odds (American odds);

The bookmakers’ odds can vary, indeed, depending on the following:

• Live betting: From the beginning of the event until it ends, the odds constantly vary depending on the probability of the ongoing of the event and how is going to be the outcome;
• Information: Bookmakers take advantage of fair odds. There are resources (people) that research to retain as much information about certain sports events to determine what the fair odds of the event and that and it can be one of the reasons the odds can vary.
• Betting volume: In case there is a high volume of bets placed in a certain event, breaks on the bets value can happen. When someone bets a high value in a certain odd, the bookmaker rapidly monitors the value and determine if that odd will fall, in order for the next bettor to place a bet in a smaller odd than the previous bettor.
• Margin of error: there are bookmakers that have a margin of error when counting the favourite teams’ odds, that’s because there are bookmakers more popular that offer different odds than others. For example: Team A has an odd of 1.20 (in this case it has around 83% probability of winning), but there are other bookmakers that can offer an odd much lower for the same event, for example, 1.14 (for this bookmaker the team has 87% probability of winning). This is a margin of error variation that is important to have in mind.