Chelsea made a strong start to the game, scoring two early goals by breaking Grimsby’s man-marking. When Chelsea started with the ball at the back, Hanson would stand on Chelsea’s free central defender, while the rest of Grimsby’s team would man-mark. This allowed many situations where Chelsea’s central defender on the ball could carry the ball forward through the entire midfield and enter the final third to create opportunities. Rotations from the midfielders, quick passes under pressure and moving to the sides (opening large gaps in the middle) would enable these situations.
In the final third, Chelsea continued to take advantage of the strict man-marking, where Grimsby’s backline and central midfielders would again try to stay tight to their man, leaving gaps around the box. Barkley quickly took advantage of this for the first goal: beating his man with the ball outside the box presented him with space to carry the ball into the box for a 1-v-1 with the goalkeeper. When Grimsby attempted to put pressure on the ball, they would leave the wing free — such as when James ran behind and crossed the ball into the box for Batshuayi to score Chelsea’s second.
Grimsby could cause problems with their tight marking, too, especially when they picked the right moments to close the distances — usually following long balls up to Hanson deep in Chelsea’s half. When the midfielders pushed up and pressed Chelsea into the corners in these moments, they had success defensively. The long ball would also be effective in that Hanson was too strong for Chelsea’s defenders, especially in the air, and he could back into them to allow the ball to go beyond him (or flick the ball on) for the runners going behind for the second ball (both wingers and 1-2 of the central midfielders) — which would see them pull a goal back.
Chelsea were very wasteful with the opportunities they had following the opening stages, where they began to attempt more passes into pressure between lines (when not needed) and attempted long diagonal passes when short passing and carrying the ball into midfield were much more effective. When they arrived to the final third, the last pass was rushed (partly Grimsby’s tight marking winning 1-v-1 duels) and few chances were created. Given the potential Grimsby had to find an equaliser from their direct play, Chelsea could have found themselves in a dangerous position, until their third goal came from winning a penalty during a corner.
Grimsby switched to a 4-4-2 for the second half, which allowed them to match Chelsea’s central defenders. This prevented Chelsea’s defenders from carrying the ball forward easily and forced them to instead make use of the spare man in midfield moving into space and overloading in order to play through while under pressure, before they’d find the wingers moving inside between lines in the final third — Chelsea’s midfielders succeeded at doing so under pressure.
The switch to 4-4-2 provided Grimsby with more opportunities and capacity to press high in moments inside Chelsea’s half (where the distances were close), and saw them defend with much more stability deep inside their own half (four midfielders narrow and backline maintaining distances to cover width of box). It also gave them the extra outlet to hold on to the ball when they won it, in order to counter and open up as a team to play with the ball.
Other than James’ improvised cross for Zouma to score, Grimsby were much better than in the first half, and only during the final 10 minutes of the game (with the game already out of reach) did Chelsea begin to pile on goals in to round off their performance in style.
xG map for Chelsea - Grimsby pic.twitter.com/18WpoG6i3D— Caley Graphics (@Caley_graphics) September 25, 2019
Chelsea easily broke through Grimsby’s man-marking, both in their own half to progress into the final third, and to open spaces in Grimsby’s backline, while using their individual talent on the ball to create and score chances early on in the first half. Chelsea’s level dropped after going two ahead and Grimsby gave themselves a good opportunity to stay in the game and build pressure, pulling a goal back from direct play to Hansen and runners behind, but the penalty gave Chelsea the two goal lead back going into halftime. Grimsby’s switch to 4-4-2 during the second half saw them have much more defensive stability, but Chelsea managed to play through the midfielders and find new solutions to advance forward with the ball, before creating and taking a number of chances during the end of the game to extend their lead and advance into the next round.