The question today is “what exactly did Pep do to change the game tactically in the second half?”
The long and (rather cliche) joke answer is: Guardiola started the match with Sterling in the false 9, then switched de Bruyne into a false 10, put Sterling in a real 7 and Sane in an actual 11, but when that didn’t work, he moved Silva from his normal false 8 role into a second false 10, put Yaya Toure in as a false 8, kept Fernando in his actual 4 and of course Bravo reprised his role as the false 1.
The short answer is: 6 midfielders.
What Pep wanted to do in the second half was get Kevin on the ball more. So he played Sterling wide right, Sane wide left, and played KdB with Silva as two number 10s backed up by the rather large scuttling crab known as Yaya Toure. Or as he put it himself:
“But in the first half Kevin de Bruyne was a little bit out of the game and that is why in the second half we put the right-footer on the right side and the left-footer on the left side and tried to get four against three in the middle. Always we have ideas, sometimes good and sometimes not. In the second half we played more without a striker, more like two number 10s to play behind Francis Coquelin and Granit Xhaka, to make the movements outside and inside.”
City did dominate the match in that second half, but it was in a way that would probably be all too familiar for a Barcelona fan: they played with six midfielders and no striker. This allowed Guardiola to both stretch Arsenal across the pitch and achieve numerical superiority in the center of the pitch. Statistically, this shows up in the fact that despite having nearly 60% of the possession in the second half, Guardiola’s City dispossessed Arsenal 9 times (to Arsenal’s 7), won 15 tackles (to Arsenal’s 9), and had 8 interceptions (to Arsenal’s 4). They dominated the ball, the space, the time, and won the defensive duels.
I think a couple of stills, both from the goals, help to illustrate this. Here is the shot just before Sane’s offside goal:
Cech passes the ball up the pitch and Xhaka actually fails to control. But notice the spacing of the City midfielders. Even if Xhaka wins that ball and brings it down to feet, he was perfectly surrounded by four City midfielders all ready to do their part to win the ball back.
If Xhaka wins the ball and nods it over Fernando, however, Arsenal have a fast break. So, you can see what the play here was but Arsenal simply didn’t execute.
Interestingly, Fernando passes to Sterling, who drives in to the middle of the pitch. Coquelin, who has the recovery speed of a love-struck teenager, snaps into a tackle and wins the ball, but it falls to Silva. Bellerin switches off (something he did several times on Sane) and Sane drifts in behind him for the goal. Yes, Sane was also an offside. The whole play only takes a few seconds but there were so many calamities in here which I think are caused by City’s numerical superiority in midfield. If they were only playing two in the middle, like Arsenal were, they have a much smaller chance of winning that ball back and going on to score.
The second is what I call “classic Pep”. Here’s the cap:
This is just a brilliant play. Clichy takes the throw in and Kevin notices how much Sane and Sterling are stretching the pitch. This creates so much space for players to run onto and spaces to play the ball. Pep loves these types of situations as well, and drills them into his teams in practice. What he’s doing here is overloading the Bellerin side with the sole intent of passing the ball to Sterling. Kevin makes the pass and Sterling is in.
Some folks complained about Monreal not showing Sterling to the end line but Sterling has never been much with his left foot*. I assume Monreal knew that Sterling was mostly right footed and showed him inside where his shot would be weaker, or (more likely) Monreal was just simply beaten by Sterling’s little stutter step. The final error here is that Koscielny doesn’t arrive fast enough to help out his teammate and Sterling’s shot slips past Cech at the near post. Also, thanks to Silva interfering with the goal from an offside position.
It’s difficult to say that Guardiola’s changes directly impacted the score. As usual with goals, there needs to be a comedy breakdown in several positions before the opening can be made. Structurally, however, the changes did make a difference in the overall game. He was able to wrest control of midfield and to create the types of overloads and openings that he wants his teams to create.
*Sterling has worked very hard in training on finishing with his left foot this season and it has paid off. He is now averaging 1 shot per game with his right foot and 0.9 per game with his left. Last season at Man City he was 1.3 per game right and 0.3 per game left.