
When Villarreal are in set defence, they meet opponents with 4-4-2 line up. When they are in set defence, team’s length doesn’t change much. It is approximately 25-30 meters.
Villarreal start to meet opponent in their own half side’s farthest point. Defense line takes position in penalty box’s 10-15 metres front. When they meet opponent this way, opponent stoppers can’t support attacks comfortably because the distance between them and Villarreal centre forwards is not too much. Centre forwards don’t press to stoppers aggressively but also they stay forward and don’t let stoppers feel comfortable.
Because now Villarreal midfielders are closer to forward more, if opponent’s one midfielder wants to close to defense to take the ball, they can cover this player quickly. So opponent’s defensive midfielders, like stoppers, can’t be comfortable.
Wingers take position in half-spaces. If opponent’s any player takes position in midfield half-space, they match with this player. If opponent’s one player is in half-space and closer to own stoppers to make game from behind, they don’t cover him immediately. Wingers take position in half-space and if this player wants to take the ball from stoppers, when the ball starts to go to this player, wingers start to close to this player. And they can close quickly because when they are in half-space and also take position forward as a team, they can close to forward quicker.
So because opponents can’t find space to make game from half-space or centre, they have to try to make game from wing. And because Villarreal don’t have a player who takes position in wing, because if they would take position in wing, this time more central spaces, like half–space and centre, would be more free for opponent, opponents can find space from wing. But it’s not a problem for Villarreal.
To cover opponent players who are in wings and half-spaces, Villarreal full backs and wingers take position accordingly. Also the stopper and the centre midfielder who are close to half-space or wing help them. The actual point is covering half-space all the time. Firstly, they assure that half-space defends well. If full back or winger have players to mark in half-spaces, they stay at half-spaces and don’t cover wing. It won’t be a problem for them. Because they take position forward as a team, when opponent’s player is free in wing, before he can be effective, they can cover opponent’s player who is in wing.
Opponent’s player who is in wing can’t be effective because now he is too far away from Villarreal goalpost. If he would be closer to goalpost in wing, he could cross the ball to penalty box or after a passing a Villarreal player against 1 vs 1 situation, he could go to penalty box with the ball and be so dangerous for Villarreal. But now, he can’t do any of these things.
To cover wing comfortably, winger needs centre midfielder to shift to half-space and full back needs stopper to shift to half-space. Or full back and winger have to stay at half-space and give opponent space in wing.
Sometimes one of the wingers could close to defense line and be the 5th player in the defense line. There is not a clear role like we can say, wingers take position in situations like that. But if opponent has an effective winger, Villarreal’s winger could stay at full back’s beside and help him to cover opponent’s winger.

Now with a theoretical example, we can understand better that how Villarreal players take position. In this situation, opponent’s left stopper has the ball. He can’t go to forward because Villarreal’s right centre forward takes position closer to him.
Opponent’s defensive midfielder number 6 closes to defense to make game. Now, Villarreal’s players have three different ways to cover defensive midfielder: Left centre forward could close to defensive midfielder and cover him or one of the centre midfielders could close to this player and cover him.
If left centre forward closes to defensive midfielder, opponent’s right stopper will have extra space. It won’t be a problem for Villarreal because even opponent’s right stopper could take the ball, left centre forward can close to him again and cover him before right stopper can be effective with the ball.
If one of the centre midfielders close to defensive midfielder, there will be a space between Villarreal’s midfield and defense line for opponent players. Villarreal players can stop this. If Villarreal’s stoppers don’t let opponent’s forward players to use this space and defend aggressively and closely or if winger shifts to centre, winger can cover this free space and Villarreal can defend them. But if more than one player have to change their positions, it can break set defence’s solidity easier.
Also, in our situation, if right centre midfielder closes to defensive midfielder and then opponent’s left stopper passes the ball to Villarreal’s right wing, Villarreal’s right centre midfielder can’t close to wing quickly to help right winger about defending.
If left centre midfielder closes to defensive midfielder and left winger has to shift to centre to cover his back, this time Villarreal’s left half-space will be free for opponent to make game. And opponent can use half-space to make game effectively because half-space is a central space. Not too far away from centre like wing.
Now let’s say that, left centre forward shifts to defensive midfielder. This time, to attack forward, opponent’s left stopper’s pass options are left back number 3 and left centre midfielder number 10. And let’s say that left stopper passes to left centre midfielder.

When left centre midfielder takes the ball in half-space, Villarreal’s right winger closes to him. Because now, opponent’s left centre midfielder is in his marking area.
Now, if opponent has clever forward players, they can confuse Villarreal players’ minds. If opponent’s left winger closes to left half-space and centre forward closes to left a little bit, they can benefit from Villarreal’s set defence mistakes.
Because now, for example, right back has to close to opponent’s left back number 3 but before being sure that half-space is not free for opponent, he can’t shift to wing. And now, if he shifts to wing and Villarreal’s right stopper and right centre midfielder don’t shift to right a little bit, half-space will be free for opponent’s left winger and opponent can make game comfortably.
In a situation like this, right centre midfielder closes to right half-space and cuts the connection between opponent’s left winger and left centre midfielder. And right stopper closes to right a little bit and don’t let opponent’s centre forward to take the ball comfortably. And because now half-space is under control by right centre midfielder and right stopper, right back can close to wing and cover opponent’s left back number 3. So opponent can’t make game. Left centre midfielder can pass to left back but after left back takes the ball, Villarreal’s right back will meet him so he will have to pass back and they will have to look another making game way.

Also I have to say that, in situations like that, opponent’s player who has the ball in midfield half-space (in our situation left centre midfielder number 10), could try to escape other player who takes position in forward half-space (in our situation, this player is left winger number 7) with a long pass. Opponent’s player who has the ball can pass to left winger because when Villarreal’s right winger closes to him to cover him, right winger doesn’t move so quickly and aggressively. So it gives time and space to opponent’s player looking at his pass options. And because now Villarreal’s defense line is high, opponent players can escape from defense line’s back more comfortably.
Normally, for example in our situation, Villarreal’s right centre midfielder covers left winger. But the problem is, left winger takes position behind him. So if left winger run forward from half-space and the ball goes to left winger from air, Villarreal’s right centre midfielder can’t cut the connection between left winger and left centre midfielder and also because left winger is closer to forward than Villarreal’s right centre midfielder, righ centre midfielder can’t catch left winger.

In a situation like this, Villarreal’s defense line has to move coordinately. Actually, it’s a basic thing. When opponent’s left winger started to move forward, all the defense line has to move right and then, they can cover spaces easily. Because if all the team moves right, right stopper can match with opponent’s left winger. Left stopper can match with centre forward and left back can match with right winger.