An environment for some players to practice pressing and tackling while the other must spread out, pass and move..
The 3 in possession are aiming to create the opportunity to play through the middle markers avoiding the screening player winning the ball. The team in possession must make at least 3 passes before playing forward, they can play down a channel but get no points for this as this is exactly what the pressing team want to force or they want to win the ball and score a goal. The team that gives away the ball becomes the defenders. Two players press but you must always have 1 screening, paint the picture of this player stopping passes through the lines, into central midfielder or strikers feet. The screening player always needs to be scanning to know what the movement is like behind him/her.