Football is a sport that uses soccer generally made of leather and is played by two teams, each consisting of 11 (eleven) core players and some spare players. Entering the 21st century, this sport has been played by over 250 million people in 200 countries, making it the most popular sport in the world. [1] [2] [3] [4] Football aims to score as much as possible by entering the ball into the opponent's goal. Football is played in a rectangular open field, on grass or synthetic grass.