Perhaps you won't have all of these memorized, but they are important to know. What you do on the field should always follow these principles.
Principles of Defense
1. Delay
Slowing down any attack is important. Delaying the opponent with the ball gives players time to "get behind the ball" and to find their "marks". Most break-aways occur because a defender charges in and misses the tackle. Four delaying tactics used against the player with the ball are goalside marking, recovering runs, pressuring the ball, jockeying, and shepherding.
2. Depth
Players must provide support behind other players. "Depth" prevents one mistake from turning into a goal. The distance that support is provided can vary with the situation, but usually no closer than five yards, no further than ten. This might also be called "cover" or "defensive support" by your coach.
3. Balance
Players "off of the ball" must cover players on the "far post" side of the field. If the ball is crossed they must respond immediately. "Balance" defending is often zone (or loose marking) rather than man-to-man.
4. Concentration
Putting as many players between the ball and the goal will make it difficult for the other team to score. This has been referred to recently as the "bunker defense". Funneling runs are used to create compactness. Overloading, or sending many players to the ball side of the field can also create concentration.
Principles of Offense
1. Penetration
A long successful pass can place many defenders on the "wrong" side of the ball. Penetration is not gained if possession of the ball is lost. A player must decide if they should pass immediately or wait for someone to get "open".
2. Support
Support reduces the defensive pressure on the player with the ball by creating more time and space. Position and movement of supporting players is critical.
3. Mobility
Players who engage in mobility tactics are usually physically fit and unselfish. Their creative runs off the ball do not necessarily result in them receiving a pass for a shot on goal but may instead open a teammate for a chance to score. Mobility of offensive players "off of the ball" causes problems for defenders and tends to imbalance the defense. Attackers who continually interchange positions force defenders to decide whether to mark these mobile players or release them to other defenders. In the process of making these decisions, defenders may be drawn out of good defensive positions or may release attackers into open spaces where they can receive a pass.
4. Width
Width is used to counter defensive funneling (concentration). Player position "off the ball", along with dummy runs, can cause defenders to spread out and create spaces that can be penetrated.
