Chelsea with the ball
Chelsea created space behind Southampton’s midfield block by drawing their midfielders forward, before playing passes over their stretched line.
When Azpilicueta had the ball in his own half, out of pressure, he would quickly take the ball forward and up to the midfield line—where he triggered Southampton’s pressure. As soon as Boufal started moving towards him he would look inside to pass to Kante. As Kante received the ball, Ward-Prowse would move up to pressure him (now with space opened behind the two pressuring midfielders) and Fabregas dropped on the outside to be a passing option in the space behind, along with Moses’ high positioning on the backline.
This move would cause a few problems to Southampton’s covering of players at the back, as they would use the fullbacks to pressure Chelsea’s wing-backs (unless it was a counter or they were exposed, where they would focus on defending the middle), use Romeu to shift to the sides to pressure Hazard or Fabregas, while the two central defenders remained 2v1 against Costa. So when Fabregas was wide he would cause problems both when he received the ball first-time (where he could play out to Moses as the backline narrowed towards him) or (when the ball went from Kante to Moses) running behind Bertrand on the inside, forcing Romeu to track him.
Along with Azpilicueta, Luiz and Cahill could take the ball forward to cause further problems. On the left, Cahill would look to give the ball to Matic or carry the ball into space before playing forward. If Matic then carried the ball forward, Hazard could drop to replace him and receive the ball back from Alonso, in space, centrally—as he did before playing the switch to Moses. Luiz would move forward with the ball if there was no pressure from midfield (from Gabbiadini) and Southampton’s lines were open (backline deep). Upon moving into midfield he would look to play passes over the top of the midfielders to Costa or Hazard, either ahead of the backline or between the lines, where they could play layoffs and create immediate danger.
Another problem Chelsea caused was Hazard moving towards the ball to receive to feet, between the lines. If Romeu wasn’t in a position to cover him and Hazard’s starting position was near the backline, he could drag Stephens out to follow him—leaving Costa 1v1 behind and forcing the fullbacks to narrow and open more spaces for the wing-backs. From there Chelsea could play over the top of Hazard to Costa’s diagonal run into the opened space, while Hazard moved around to look for the second ball from Costa.
When attacking in the final third, Chelsea could use Fabregas and Hazard to overload one side and open spaces in the backline for runners behind (Southampton had to cover centrally and the fullbacks were stretched to cover the width from the wing-backs).
If Chelsea lost the ball, the central midfielders and defenders would press aggressively to recover the ball, or foul if Southampton managed to break past the first lines of pressure—Cahill and Azpilicueta ensured they remained close to Southampton’s wingers.
Southampton’s problems in defending during organised way were heightened anytime they had many players inside Chelsea’s half and when Chelsea were countering. During broken play and counters, Fabregas moving centrally to act as a third midfielder often allowed him time and space on the ball to play forward passes to Costa or Hazard. This was evident in the buildup to the first goal, where Fabregas received the ball before immediately looking for the pass to Costa.
When Southampton’s midfield line was in Chelsea’s half, their backline remained fairly deep (not playing offside) and created a large open field for Chelsea to move into when they won the ball deep. This allowed Chelsea to directly play towards the front line deep inside Southampton’s half on a consistent basis. Romeu was supposed to keep their backline from being constantly exposed, but he was often dragged to the sides or dribbled past by Hazard—though he did intercept or win the ball to stop the attack on a couple occasions.
Southampton with the ball
Southampton used the wings to advance and try to work the ball for a cross or pass into the box. When they were able to move the ball up the wings and into the final third, they could hold possession by having both wingers on the same side as the ball, along with support from the fullbacks high on both sides. When the wingers were able to receive the ball facing play (especially Boufal), they held the ball well and continued moving the ball forward to gain territory, allow them to move up as a team and win set pieces.
Behind the ball they would have the central defenders (Stephens moving up to get tight with Hazard), Romeu and one or both of the central midfielders back to apply pressure to prevent counters if they lost the ball, but as detailed above, the gaps were often too big between them.
When Southampton tried to play central passes forward between the lines, they were easily pressed and won by Chelsea’s backline. Not only were they easily pressed when they were ready for the ball, but on a few occasions the front players weren’t anticipating the passes to be made to them in the first place, leaving them open to counters.
Set pieces were their biggest threat, with excellent delivery from Ward-Prowse. They always used a player to loop around on the right, with a blocker on the side of free kicks played into the box to create the freedom on the outside. From corners they also used blockers to free the runner looping around, grouping four of their players around the penalty spot, before splitting. In doing so they could create a block ahead of Gabbiadini, allowing him to freely loop around the back to receive the ball when it went past the far post.
Southampton’s front line and midfielders moving too far up was detrimental to them throughout the game, allowing Chelsea to open space by inviting pressure or to play directly behind their backline when out of pressure. Furthermore, Southampton had difficulties covering Chelsea’s front five during counters, as Romeu could be moved out of his central area ahead of the backline (either wide or beaten when pressuring high) leaving them exposed at the back.