There are many types of four-back alignments in soccer, that are applicable to several formations. One of the most popular, especially among high school age teams is the diamond defense.The diamond defense features two fullbacks, a stopper and a sweeper.Here is how to effectively shut down opposing offenses with a diamond defense.
Sweeper: The sweeper is the last line of defense. The sweepers job is to patrol the back horizontally. The sweeper should attack the ball any time it gets past the fullbacks. Often times, good sweeper play is about taking the proper angle on the ball. Whether it's at the feet of an opposing striker, or it's a through-ball that the striker is trying to catch up with, the sweeper needs to make sure that he or she takes an angle that keeps the offense out of the middle.The sweeper should not be marking unless it's a last priority, because at any given point, he or she will have to attack the ball, and leave that mark.
Fullbacks: The fullback's primary objective is to mark. With a diamond formation, the fullbacks often end up marking players making long runs down the touchline, although they have to be ready to cover inside runs and diagonal runs. If the sweeper attacks a player coming down the touchline, the fullbacks should fall into the middle.The primary job of the fullback, when guarding a player that already has the ball, is to force them in one direction of the other. The fullback should have an angled stance so that even if the offensive player can keep possession, he'll only have one direction to go. That way the sweeper and midfielders know where the ball is going.
Stopper: The stopper is very much like a defensive midfielder. He or she will often be responsible for marking runs that go straight down the middle.The stopper will also be responsible for attacking anyone dribbling the ball up the middle of the field. Much like the backs, the stopper should aim to force the player in a direction. The stopper will also get several opportunities throughout the game to make runs on the offensive end.
Midfielders: It is very important in a diamond defense that the mid fielders come all the way back on defense. More so than in a flat back four because the fullbacks can easily get caught with two players to mark, and that leads to dangerous opportunities for the offense.