Chelsea with the ball
Chelsea were initially unable to maintain the ball when playing forward. This was a result of being unable to draw Brentford to the ball before switching—or finding free players. Trying to continue possession up the starting side of the attack also allowed Brentford to use their central midfielders to shift over in order to both press and cover the forward passing options.
Sitting off, Brentford were also able to shift over to overload the areas around the high receivers when Chelsea did switch the ball to the other flank.
Early advancement of the wide central defenders on the ball was also met with the Brentford midfield around the options and outnumbering Chelsea numerically. This resulted in Azpilicueta attempting a ball behind the defence for Willian (Azpilicueta advancing after a pass from Terry and no high pressure from Brentford), unsuccessful passes forward to the front players, and Zouma being forced to pass backwards after advancing with the ball (after a switch without pressure on the ball).
When Chelsea were able to find passes to the front players and were able to retain the ball, they could then switch the ball to the other side to be able to find forward passes directly against Brentford’s backline.
In the following situation, Cesc collected the ball from Zouma and played forward to Willian, where Bjelland was unable to get tight to Willian when he received the ball. As the play continued they moved the ball to back to Cesc (moving forward, between Brentford’s front line and midfield line, in order to receive the ball in space), and then he could play a pass to Batshuayi making a run behind, into the space left behind Bjelland—a result of his higher positioning from trying to pressure Willian.
Cesc being able to get into these positions allowed him to play various forward passes throughout, where he could switch to Ake, play behind the defence, into the box or play forward to feet (such as the long shot from Loftus-Cheek in the 29th minute).
After the first goal, Brentford had moments of higher pressing after playing long into Chelsea’s half. It was during these moments when Chelsea had the most success with the ball, making good use of switches and passes onto the last line against Brentford’s open block. With Brentford’s central midfield shifted over and high up to press the ball, they were unable to recover the distances to be able to block or support Chelsea’s forward passes onto the backline.
The second goal arrived in a similar situation. Chelsea won the ball deep but under pressure—after Brentford played long—but Willian was able to pick up the ball and play forward. Bjelland is only able to get back behind the ball (but not in the backline) as Batshuayi passes the ball into the space left by him in the backline—Loftus-Cheek and Pedro both running into that space; Pedro able to outrun Barbet, before finishing.
During longer periods of possession in Brentford’s half, Chelsea managed to create some more opportunities to draw them to one side before switching, and then quickly advancing up the wing. Brentford had good cover of crosses (even with Ake joining the box with the ball on the right) but Willian was able to create a lot of chances individually by dribbling with the ball up the wing—blocked crosses could then lead to quick and short corners to the players on the edge of the box. One such situation lead to winning the free kick for the first goal. When Chelsea didn’t put the cross into the box they could go back with the ball and find the central midfielders facing play and out of pressure—due to the deep positioning of Brentford’s midfield—allowing them to play forward or into the box.
Brentford more aggressive at the start of the second half
In the second half Brentford began to be more aggressive with their pressing, both in organised play and when Chelsea tried to counter. The backline were tight to Chelsea’s front receivers, either taking the ball or fouling, while from midfield upwards they were able to close the distances down in order to press the ball.
This created a much more stretched and faster game, where Brentford were able to recover the ball and attack quickly—Chelsea now unable to sustain possession in Brentford’s half and press them in numbers when they lost the ball.
When Brentford lost the ball high in Chelsea’s half, they often used fouls to prevent the counter attack. If Chelsea were able to avoid the fouls they were able to create dangerous counters, such as Willian’s carry with the ball before Loftus-Cheek’s shot inside the box.
Brentford relied on their wide players with the ball, using runners from inside to go behind the wing-backs, as well as putting the ball into the box more often with crosses and set pieces.
Ake was well positioned in this case to clear the ball, with Colin making the late run at the far post.
On one occasion, Brentford also managed to hold on to the ball after drawing pressure from Fàbregas and Chalobah, before finding a pass behind them for Woods.
When Chelsea were able to break the press while building from the back, Brentford were exposed. The best example of this was the buildup to the third goal (Ivanović), where Chelsea played through the pressure and created a large overload on their backline.
Conclusion
Chelsea were able to control the game well in the first half, while managing Brentford’s best period of the match at the start of the second half. Begovic made some crucial saves during this period, along with clearances of loose balls inside the box from Chelsea’s defenders, before Chelsea were finally able to play through Brentford’s pressure to score the third. After that, Brentford’s intensity dropped and Chelsea regained control of the game for the rest of the match.