In the 21st century, betting on sports has been revolutionized by technology. Online systems have been developed to enable enthusiasts to stake their claim on the outcome of upcoming matches. As an online gambler you can put your knowledge and skills to the test to predict the results of sports matches. Before doing that, you need to understand how to work out football betting odds. This is the first basic step that you need to master if you want to start betting on sports. The next step would be to understand all the variables that effect the final score of a football match.