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?

2. Why it worked

The new formation and system is perfectly suited the current crop of players.

Rob Holding and Shkodran Mustafi love to get forward. In a partnership, this left the defence completely exposed and vulnerable to the counter. In a trio, when one gets forward, there are still two central defenders to snuff out counter attacks.

The new system also let the wingbacks attack without fear of being exposed.

Moving Alex Oxlade-Chamberlain to this spot was one of the revelations of the season. Despite saying he wants to be a central midfielder, the Ox seems to have found a new home that will get him consistent playing time.

Surprisingly, Nacho Monreal also shone in his new role. Nacho had seemed on the out, with rumours circling for several transfer windows that Arsenal were in the market for a left back. But whether he played as the left centre back or as the left wingback, Nacho played exceptionally well. He even bagged the winner against Manchester City in the FA Cup semifinal.

All of the wingbacks shone going forward. Goals and assists abounded.

Monreal and Bellerín bagged goals. The Ox looked incredible swinging in crosses. In the Manchester United match, he logged two assists, including a beautiful cross right onto Danny Welbeck’s head.

Alexis Sanchez and Mesut Özil have always been players who like to roam. They do not like to stick to one positional area on the field.

Previously, this left Arsenal wide open after turning the ball over, which Sanchez does quite often. The 3-4-3 allows them this freedom.

They can go wherever they need to in order to create, without being exposed.

The solid defensive base and two strong central midfielders allow them to go anywhere on the pitch.

This led to a free-flowing attack that decimated opponents in the run in.

Next, for the future…