American football positions four linebackers, and four defensive backs (two cornerbacks, a strong safety, and a free safety) Special teams are units that are on the field during kicking plays. While many players who appear on offensive or defensive squads also play similar roles on special teams (offensive linemen to block, or defensive players to tackle) there are some specialist roles which are unique to the kicking game. American football positions In American football each team has 11 players on the field at one time. The specific role that a player takes on the field is called his position. Under the modern rules
Comparison of American football and rugby union only one of the three being on the field at a time. That is to say that in professional American football, the majority of players play in only one specialization (or "one side of the ball") – however, every player is eligible to play in any specialization. In rugby the teams are divided into eight forwards and seven backs. Both groups of players partake in attacking and defensive plays and are on the pitch at the same time. Only the eight forwards take part in the "set pieces", which are ways to contest ball possession when there is a minor