# Variation in sports betting

There is a lot of variance in sports betting. It is important to be prepared for this and not to invest too much of their available funds per tip voucher.

## Unexpected Results

If you are serious about trying to make money playing odds then it is important that you do not invest too much of your available funds per bet voucher. The variance will take you again if you are not careful. Poker players know this as bankroll management and in good Norwegian they say not to put all the eggs in the same basket.

Unexpected results happen all the time. We have seen this very clearly in the Soccer World Cup 2018 where Argentina lost 0-3 to Croatia, Germany lost 0-1 to Mexico and Brazil played 1-1 against Switzerland in the group stage.

Big swings are expected in every form of gambling and sports betting is not the exception that confirms the rule. When you find Value Games you rarely have more than 5% takeover of the bookmaker. Usually, the benefit of a Value game is 1-3%. With such small margins, the variance becomes extremely high and the capital requirement thereafter high.

## How much should you Bet?

The worst thing that can happen to a professional odds player is to go broke. A carpenter cannot work without a hammer and an odds player cannot work without money.

We have previously considered the importance of playing with units in sports betting. In that article, we advised beginners not to invest more than 5% of their available funds on a single voucher. We shall now take a closer look at this.

## Probabilities

Most who have gone to university and college have learned about expectation value and standard deviation in probability theory. If you have not learned about this, or have forgotten about the book, expectation value can be explained as average over time; and standard deviations such as how far from the average a result can be.

### Expectancy value in sports betting

The more you play the closer you will get to your expectation value. Since the bookmaker has a built-in margin in each game, most hobby players will go minus in the long run.

## Variance in Sports Betting

Professional odds players often have long periods where they go minus, but they by definition go in plus over time. How many games must a professional odd player place before he goes plus? It depends on the variance.

### Sports Betting Variance Sports Betting

Variance describes the difference between actual result and expected result. If you only play high odds you will experience high variance and therefore need more capital to avoid breaking.

This can be produced mathematically. Some may remember that variance is described as the square root of the standard deviation. One standard deviation describes something with 68% probability, 2 standard deviations describe something with 95% probability, while 3 standard deviations describe something with 99.7% probability.

### Normal distribution

Expectation value and variance can be used to show normal distribution . Here we see that even though the expectation value is 0, there is still a great chance of very poor results in the short term.

The picture below shows the normal distribution of outcomes over time.

### Simulations

We have simulated returns on sports betting using 10 units, 5 units and 2 units. In all the simulations, 8 people start with 1000 kr. 51% of times they win 100 kroner and 49% of the times they lose 100 kroner. This is a profitable strategy, but it may not work as well for everyone.

#### 10 units:

Here we see that two of the eight players go broke and only three of them have earned over 1000 kroner after 1000 games played.

If you play with 10 units on each match you can quickly break.

#### 5 units:

When we run the simulation with 5 units on each match we see that three of the players break within 1000 games played. This time only two of the players have gone in plus.

Betting 5 units on each match is also not safe.

#### 2 units:

By betting 2 units on each match we see that none of the eight players have lost everything. Two of them have made a lot of money and the unlucky player has only lost \$400.

The results will be better if you only bet 2 units per match.

## Conclusion

We cannot recommend playing with more than 2 units on each coupon unless it is a good value game that has more than 1% margin over the bookmaker. If you find a fighting game with a 5% margin above the bookmaker we recommend you bet 5 units. 10 units is too much to bet even with such a large margin. It is simply too much variance in sports betting to invest 10% of your funds on one betting coupon.

It is also worth noting that this does not matter if you do not have a profitable game. If your expectation value is negative then all the money will be lost sooner or later no matter how much you bet, unless you stop playing.