There are four key elements that I have found to teaching young soccer players to defend effectively. Footwork is a key factor in getting young soccer players to defend effectively. Together with knowing when to commit to a tackle and when to hold position I find these are the two vitals elements to having a strong defence. These factors, I combine with knowing where the danger zones are on the field, and communicating with each other in order to create an impenetrable defence. I do not promote playing boring soccer with lots of players behind the ball, but if you can defend effectively then your team will be able to play the ball further up the field, thus creating more attacking opportunities. Soccer is a game about field position and possession and being able to defend effectively is a key element for each of these factors.
Footwork is a key element in teaching young soccer players to defend effectively. There are two things that I focus on with my young soccer players in relation to their footwork. The first of these is to never get caught with their feet square. They should always defend with one foot in front of the other, and with one shoulder in front of the other. They must also never be caught flat footed. This means that they should always be on their toes in a defensive situation. This allows them to react much more quickly to what the attacking player does in front of them. It is also vital that they do not get caught with both feet off the ground at the same time, as this makes it almost impossible for them to change direction or react quickly.
Players must learn when to commit to a tackle and when to hold their position and wait for an opportunity. Players must only commit to a tackle when the odds are in their favour of winning the ball. This usually means that they are closer to the ball than what the attacker is. Until this happens they should jockey for position and maintain a distance of about 1 meter between themselves and the attacker. This will give them enough reaction time to stay with the attacking player. Players must watch the ball at all times. This will lessen the ability of an attacker to fake them into committing to a tackle at the wrong time. The ball is the critical element, not the feet, hips or shoulders of the attacking players. Teach your defenders to watch the ball at all times. I also encourage players to stay on their feet when defending as much as possible. There is a time and place for a slide tackle, but a player that is off their feet cannot react as quickly as a player who is on their feet.
Teach your players where the danger zones are on the field. Defenders must position themselves on the field to push the attack towards the sidelines and away from the goal mouth. Teach them how to position in front of an attacker to encourage the attacker to move into a less attacking area of the field.
The key to any successful defence is communication. In my junior teams I always find my defence much stronger where I have a strong communicator playing in the sweeper or centre back role. Communication starts at training. Whenever you conduct drills at training ensure that you are not the one doing all the talking. Make sure that there is plenty of talk amongst your players. What they do on the training paddock they will take onto the field.
So the four keys to creating a strong defence are teaching your players correct footwork, making sure they understand when to commit to a challenge, helping them understand the danger areas on the field and how to keep attackers away from them, and making sure they communicate with each other. Your defensive drills should encourage development of these four key areas, in order that you will have a strong defence.