This season, a new formation and tactical system swept the Premier League, and to some extent world football.

Previously, using three centre backs was something mostly seen in Italy. The 4-2-3-1 and 4-4-2 dominated English football.

But by the end of the 2016-2017 season, most teams had at least tried some form of three at the back. What changed? Why so quickly? Why did this system work so well for Arsenal?


1. Antonio Conte and the Copy Cats

At the beginning of the season, Chelsea were a joke.

They had just finished a terrible season, and Alexis Sanchez and Mesut Özil ripped them apart. Conte was expected to be fired at any second.

But then, he pulled out the formation he used frequently with Juventus and Italy: the 3-5-2 and 3-4-3. The Blues pulled a fullback, Cesar Azpilicueta, inside to one of the central spots. He had a fantastic season, surely one of their best players. This accommodated Marcos Alonso, allowing him to get forward, elbow Hector Bellerín in the head, and get goals.

The effects were immediate.

Chelsea completely turned their season around (unfortunately), eventually going on to win the title and almost the double (thank you Aaron!).

Antonio Conte having success with this system in England made it spread like wild-fire.

The Premier League went into complete copy-cat mode. First, struggling teams fighting to get any momentum gave it a try.

Hull City deployed it when they were out of answers, Tottenham used it in several games.

Even Gareth Southgate gave it a try with England against Germany.

All of these formation experiments were trying to replicate Chelsea’s immediate success upon switching formations.

These were a bit of a mixed bag. Sometimes it worked, sometimes not. This is probably due to the fact that Conte has much more experience deploying these formations than the other managers.

At Arsenal’s darkest hour, with Arsene Wenger desperate for results, the Gunners came out in a 3-4-3 against Middlesbrough.

Using the new system, Arsenal won 9 of their last 10 games in all competitions to bag an unlikely trophy and almost snatch fourth place.

Next, why it worked…