Defender (football):
The sweeper is a more versatile type of centre back that "sweeps up" the ball if the opponent manages to breach the defensive line. His or her position is rather more fluid than other defenders who man-mark their designated opponents. Because of this, the position is often referred to as libero (from the Italian word meaning free). The sweeper's ability to read the game is even more vital than for a centre back. A sweeper is sometimes expected to build counter-attacking moves, and as such requires better ball control and passing ability than a typical centre back. However, sweepers are often merely defensive players. For example, the catenaccio system of play, used in Italian football in the 1960s, employed a purely defensive sweeper who only 'roamed' around the back line.