probability, the basics

This section is under development and will be updated regularly

Probability is probably the most important concept to understand if you are going to bet on anything. There are statisticians and probability wizards who spend year's studying the subject and it can be very complex. Luckily we don't need to be statisticians to bet on football ( or anything else really ), but we do need to have a basic understanding. Probability does not mean something will happen, it is just a way of calculating the likelihood of something happening.

Probability is the measure of the likelihood that an event will occur

So what does that mean? The simplest example of calculating probability is to use coin flipping. There are only two possible outcomes that can happen with a tossed coin, it can be heads or it can be tails. We calculate the probability by using this formula:

P(A) = 
The Number Of Ways Event A Can Occur
The total number Of Possible Outcomes

P means Probability and A is the event.

heads or tails

Let's calculate the probability of a coin toss being heads. P(A point toss) = heads? The number of ways this even can occur is 1, there is only head on a coin. The total number of possible outcomes is 2, there are 2 different possible outcomes of a coin toss, heads or tails.

P(A) = 1/2 ( or 0.5 or 50% )

So our probability can be expressed as 1 in 2, ( or 0.5 or 50%. Makes sense. If we were crooks and were using a two headed coin then our probability would be 1, an absolute certainty, because the equation would be P(A)=2/2 as the number of ways the event can occur would be 2 - 2 heads on the coin and the number of possible outcomes would also be 2. If you are ever offered odds on any outcome with a probability of 1 then mortgage your house, sell your children and take the bet!

probable wobbablle!

Just because we have a probability of 0.5, it obviously doesn't follow that the spread of the outcomes will be even, we would not expect to see each heads coin toss followed by a tail, we could see 19 heads and 1 tail in 20 tosses and that would seem to make our probability calculation meaningless, but if we were to increases the number of tosses to hundreds, thousands, millions, the number of heads and tails would be very close to 50% of each outcome.

silly system - roulette

We have seen some very silly betting systems that work on the premise that a result is 'due'. One of them was based on Roulette where the probabilities of the ball landing on red or black are very close to those of a coin toss.

The actual calculation of the probability of a red or black spin on a roulette wheel is "

P(A) = 18/37
as there are 18 different red or black segments and 37 possible outcomes as the zero segment is the one that causes the wobblies. So our P is actually 0.486486486, not 0.5.

The so-called 'system' stated that if red or black had not been spun for a certain number of spins then it was 'due'. That is total nonsense as the ball does not know where it has been and every spin is a totally independent event, there could be hundreds of consecutive backs or reds. You can not make money on systems like this as the casino will offer you odds of even money ( 2.00 in decimal odds) on a bet that they will win 19 times out of 37 in the long term. We will be covering probability and odds in a later article.

another example - dice

What is the probability of one die showing any particular number? P(A)=1/6, there is one way the event can occur as we can only have one face showing and 6 different numbers on a die.

The probability of any specified number being thrown with a single die is 1 in 6, ( or 0.16666 or 16.666% )