This type of defence was introduced in the pre-war era and dominated world football for decades, while today it is the simplest one. The players of one team cover the opposing players man-to-man. In contrary to a zonal defence, every defender has a clear task. Nevertheless, there are different types of man-to-man marking. A team can use all ten outfield players to assign each of them to the opponents or a team utilizes a free player behind the deepest markers – the so-called libero. Nowadays, only a few professional teams prefer a radical man-to-man defence. Some coaches apply a space-orientated man-to-man defence, which means that the defenders initially cover a certain zone, but start to cover an opposing player when he or she enters that zone. Other than that, the best opposing playmakers or forwards are sometimes rigorously marked by good defenders.