One of definitions of value says that value is relative worth, merit, or importance of something. If we translate this definition to betting, value bet would be relative worth, merit or importance of a bet.

Key word in this definition is relative, and that’s why most of the punters have different perception of value.

One punter will place a bet and examine value of a bet on their deep knowledge of football teams, which include team news, moral, motivation, weather, etc, etc.

Another punter will take a deep look into statistics on the other hand and won’t pay much attention to team news.

Which punter is right? Probably both of them, but I prefer the latest one’s method.

Online betting is basically all about numbers. Odds are numbers, so when deciding about placing a bet or not, one should have some exact methods, numbers based, in order to beat bookmaker, who definitely used a lot of science in order to determine his odds.

So, if we could translate all the data we collect about one betting event into numbers, we would be able to calculate percentages of all outcomes, and to be 100% sure we have value or not.

But the problem is measurement of our data. How would you measure importance of Wayne Rooney for outcome of Manchester United football match? You can say he’s key player, or he’s important player, whatever, but how will his eventual absence affect Manchester United chances to win their match? Will their chances be 2% or 5% less if he’s not playing? Of course, there is no right answer to that question, so we have to find some other methods to measure our value.

One of the ways for turning our data into numbers is Rating Systems. There are lots of rating systems available and can be found on the internet, but what all of them have in common is to provide objective ratings for each team. There are a variety of methods for rating teams or players, and one of most common calculation is known as a power rating. The power rating of a team is a calculation of the team’s or player’s strength relative to other teams in the same league or division.

While official standings in most of the sports are based on numbers of wins and losses, extended with draws in some sports like football for example, rating systems are trying to find alternate measure of team’s or player’s strength.

In football for example, there are several systems which are based on number of goals scored, and one implementation of such a system is Goal Rating System.

The other group of systems is based on various stats – possession, shots on goal, corners, etc, while there are some systems which are also based only on number of wins, losses and draws, but with different points system.

But no system can take into account everything that can happen in sporting event. Still, there are some advantages of using rating systems:

•    Ratings are objective
•    Ratings are repeatable
•    Ratings are exact

There are disadvantages also, and some of them are:
•    Ratings usually use just one segment of game – just scores or just number of goals for example
•    Ratings usually don’t take into account factors such as weather
•    Ratings don’t take into account phenomena known as “games thrown away”, i.e. games where one team or player clearly lacks any motivation and is prepared to give specific game away, in situation when points are not needed any more.

For more about rating systems try searching on Wikipedia or Google, I’m sure you’ll find something interesting.