Playing a high defensive line is a risky team tactic in soccer, but incredibly effective at limiting the opposition’s attack when executed properly.
When a team’s defensive line is deployed higher up the pitch, the opposing team has less time and space on the ball, making it harder to generate a cohesive build-up. Though the name of the tactic comes from the positioning of the backline, playing in this style requires every player on the pitch (including the forwards) to press high and compress the field. This can provide the advantage of being able to break quickly when winning the ball.
The approach is not without its downsides. Most teams will try to beat a high line by instructing a forward with pace to time runs behind the defensive line into the large amount of space that’s left between the defenders and the goalkeeper. The rest of the team will look to play long balls over the top to that forward or forwards, and if they beat the offside trap, there’s no one left to stop the striker and he or she will have a 1v1 with the keeper.
To successfully play with a high line, a team needs to have defenders with good recovery speed and high levels of cohesion among its backline. If even one player fails to step forward in time to shift the offside line, the entire system falls apart. It requires some extra time in training, but once a group of defenders develops chemistry in the system and learns to time their movements off of each other, it can be very effective.