Sports Betting Mistakes: 3 you must avoid (2023)

  • 10 mins read

Betting using gut instinct (rather than looking for value) is one of the biggest sports betting mistakes you can make. Also, what should you avoid doing with your bankroll? And, why should you stay away from arbitrage betting?

  • We cover the reasons why we think you will need to avoid these 3 sports betting mistakes, in our detailed guide.

Avoid gut instinct – look for value instead!

value bet compared to gut instinct bet

Once of the biggest sports betting mistakes you can make is Gut Instinct betting. This involves placing bets on outcomes of events, just because you fancy teams/players to win, without considering the odds fully. If you are doing this, then you will likely be losing money in the long run.

Instead of this you will want to be Value betting. This involves independently considering if the odds offered are better than the true probability of the outcome happening. Then, only placing bets if that is the case.


  • Let’s say you are considering placing a bet in an event in which there are two outcomes only. For example, the final of a competition where either team/player A wins, or team/player B wins (no draws possible).
  • You need to calculate the true probabilities of the outcomes. This requires taking into account a lot of factors. Examples are prior results, injuries, officials, form etc. Factors will depend on what event you are betting on. Then, come up with a statistical model (which may require, amongst other things weighting the factors).

Betting for value

Let’s say you calculate A wins two-thirds of the time, and B wins one-third of the time:
Two-thirds of the time is the same as fractional odds of 1/2. That is to say for every 1 time they don’t win, they will win 2 times.
One-third of times is the same as fractional odds of 2/1. That is to say for every 2 times they don’t win, they will win 1 time.

Let’s say you go to your favourite bookmaker offers the following odds (this is a made up example):
1/4 on A to win
12/5 on B to win

If you are betting for value:
You must NOT bet on A, as 1/4 are worse odds than 1/2
You should bet on B, as 12/5 are better odds than 2/1

Why might bookmakers sometimes offer actual value?

  • The reason you may find better than needed odds on a particular outcome, is bookmaker’s odds can vary depending on a number of factors.
  • Perhaps a bookmaker wants to attract more money to an outcome. This is so they can offset potential liabilities, on bets taken on other outcomes.
    • For example, if England are playing in the World Cup, you may find their price to win the tournament (at UK bookmakers) are well lower than statistical calculations of their true probabilities would warrant.
      • This may occur if lots of home fans are backing them only due to their support for the team, or gut instinct.
    • This could mean prices for other teams are higher.
  • Or, perhaps a bookmaker is doing a promotion. An example is enhanced odds on one (or more) of the outcomes in an event.

Tips for finding value

  • Finding value means independently calculating the probabilities of an outcome in a market. Or, even better all the outcomes in a market. Then, converting this to odds you will require.
  • Then check the odds of the outcomes, versus the odds offered at your favourite bookmaker.
  • If the odds offered on an outcome are better than what you require, then placing a bet will mean you win in the long term. This is provided your independent statistical models were accurate. In reality this would be difficult to do anywhere near 100% correctly.
  • Of course, even if your models were 100% correct, your bet will still lose a certain % of the time. For example, suppose one-third of the time a team will win according to your probability calculations. If that’s the bet you place, two-thirds of of the time you will lose.
  • However, with good bankroll management you place multiple bets on different things. You only place a small % of your total available funds, on any one bet. If you keep placing bets that offer genuine value, you have a decent chance of winning money in the long run.
  • Compare this to just betting on gut instinct. That virtually guarantees you to be a long term loser, as bookmakers build in a profit margin into their odds. This is why we have placed it top of our list of sports betting mistakes

If you are looking for value, we also strongly recommend you avoid high overrounds and stay away from accumulators (as overrounds are multiplied).

Never mismanage your bankroll

Mismanaging your sports betting bankroll is also one of the biggest sports betting mistakes that you could make.

Here’s a simple example of why bankroll management matters:

mismanage bankroll
  • Let’s say that you have £1,000 to gamble with in total in your sports betting account with a bookmaker. You have no way to replenish this money if you lose.
  • Let’s say you were betting on an event with only two possible outcomes. The bookmaker was offering 6/5 on outcome 1, and 1/2 on outcome 2 (this is a made up example).
  • Let’s say according to your value bet calculations, you thought the true odds of each outcome was 1/1. That is to say there is a 50% chance of outcome 1, and a 50% chance of outcome 2.
  • Of course you would want to bet on outcome 1, as you are getting better odds than required. You would never bet on outcome 2, as you are getting worse odds than required.
  • If you bet £1,000 on outcome 1, there’s nothing intrinsically wrong with the bet in terms of value. After all, you will be making £1,200 profit if outcome 1 happens!
  • However, what if outcome 2 happens? 50% of the time it will, and you will lose your stake of £1,000. As this was your whole bankroll, you will be completely broke!

So what’s the solution?

  • When it comes to sports betting no matter how good a sports bet looks, don’t make this mistake. If you bet your whole bankroll on one thing, you are going to lose it all some % of the time. This is because no outcome is ever likely to be 100% certain to happen.
  • A often recommended sports betting bankroll management formula is the following. Only bet a maximum of 5% of your bankroll on any one bet.
    • Notice, that as your bankroll increases your bets become bigger (as we are calculating 5% of a bigger bankroll).
    • Conversely, as your bankroll decreases your bets become smaller (as we are calculating 5% of a smaller bankroll).
    • This system makes the difficulty of losing your entire bankroll large. At the same time, it gives you the chance to win more when you are doing well.

Avoid Arbitrage betting

arbitrage betting

Numerous websites and software tools have popped up which claim to allow you to spot guaranteed profitable betting opportunities. They show you ways of taking advantage of the differing prices on outcomes in the same market between different bookmakers. We explained how you could start to find the best value markets at your favourite bookmaker. This involves working out the overround on a particular market. The lower the overround the better.

However, these websites and tools take this a step further. They claim to be able to find opportunities when there will effectively be no overround. Thus, the book will be less than 100%. This is called arbitrage betting (placing bets at multiple bookmakers, on different outcomes in the same market).

We see arbitrage betting as one of the big sports betting mistakes to avoid. This applies even though the opportunities will be real (unlike the betting tip scam) if using a reputable service.

Why avoid arbitrage betting?

  • There is usually a fee involved to use these services, which may wipe out profits, or even mean a loss.
  • Bookmakers generally hate arbitrage betting. Many share data for numerous reasons, and this helps them spot arbitrage betting. Depending on their T&Cs, they could refuse to honour bet(s) and/or close your account.
  • Even if they weren’t sharing data, if there is a good arbitrage opportunity (which if the service you have paid for works, it should spot), lots of people will be placing the same bets as you in the same time period. It will not be hard for bookmakers to suspect arbitrage betting, and revoke bets if that’s their policy.
  • Bookmakers who care about responsible gambling (which should be the case with any reputable bookmaker) may also close your account. They may do this if you are making huge losses at their bookmaker. They won’t know you might be winning overall across all your accounts at different bookmakers.

Even if bookmakers didn’t have problem with arbitrage betting (which they do), there are numerous other problems which mean you should avoid arbitrage betting.

More reasons to avoid arbitrage betting:

Fluctuating odds

It is possible that you place one part of your arbitrage opportunity at one bookmaker, and when you go to place the other bets to make your arbitrage opportunity work at one or more other bookmakers, the odds have changed. Odds can fluctuate at any time. If other people have spotted the arbitrage opportunity, bookmakers may be receiving a lot of bets on something, and the odds will likely change (not in your favour).

Confirmation delays

If you spot a brilliant arbitrage betting opportunity, and wish to place large bets, and only have a short amount of time, it can be difficult to see if your bet has been accepted. Some bookmakers only accept smaller stakes automatically, whilst larger stakes need to be manually verified by their traders. This process is usually quick, but not instant. This means you may not be sure all the parts of your arbitrage have been placed.

Errors due to hurrying

It is possible that in the short space of time that you have to place bets, you make an error. An example would be incorrectly calculating the amount to bet on each outcome and/or bookmaker. Even if your software/tools correctly calculate amounts to bet for you, you could also incorrectly place your bet. For example if any bookmaker has an unfamiliar user interface. Of course, your error might work in your favour – but, you certainly don’t want to be relying on that.

Different bookmakers

Successful arbitrage betting often requires several accounts at different bookmakers. This can take up a lot of time maintaining the different accounts, making sure they are all funded. Also not all bookmakers will be well known to you – less reputable bookmakers often making depositing easy, and withdrawals painful. Of course you will have to be wary of any scams, from unknown bookmakers.


In conclusion, we urge you avoid arbitrage betting altogether, and not pay for any tools/software to help spot arbitrage opportunities. Instead, we recommend you stick to looking for bets you think have value, at whatever your favourite bookmaker is.