Here are some basic pictures, to help players understand how to defend from the front. The team are set up in a 4-3-3 (Barca colours) but the principles will work for most systems and shapes.
ROLE OF THE STRIKER
I ask the striker to "CUT THE PITCH", this gets the opposition to "Play one way". In the diagram below the Striker is allowing the Centre Back to have possession but only to play to his right side.
This will challenge the Centre Back to...
Play in to the right back - who is being closed down by the winger
Play in to the centre of midfield, where we should be strong in a 4-3-3
Play it long, our defenders should anticipate a direct ball and be ready to head it back. They must also be aware of the space behind.
ROLE OF THE WINGERS
I ask the wide players to SHOW INSIDE. So when Full Backs receive the ball the Winger must stop the opposition full back playing in to the feet of their Wide Player.
The angle of approach is key here, the wide player must angle his run to cut the line and send the full back inside.
The Winger may need to prioritise, they may have to CUT THE LINE before they can win the ball. Often the work of the Striker or Winger will set the midfield up to win the ball and/or force the position to make a mistake and turnover possession.
In the picture above note...
1. Striker has CUT THE PITCH by getting between the Centre Backs
2. The Winger has angled his approach to CUT THE LINE and show the Full Back inside
3. The Winger on the opposite side has made the pitch narrow and started to come inside. This will stop the opposition Midfield switching possession to the full back and will decrease the space for the Central Midfielder to operate in
4. The Midfielders are tight and compact, denying space and forcing the opposition to play predictable passess
5. The Left Back has anticipated that the Winger may become active, he is aware and ready to engage