Why did the back three come back?

Suggest “let’s play three centre-backs” to a coach in the mid-2000s and he would probably have looked at you as if you’d stepped out of a time machine. Those were the years of the back four, the 4-4-2 and the 4-2-3-1. The back three was a memory from the 80s and 90s.

Today the picture is completely different. Some of Europe’s best teams openly play with a back three, and plenty of sides that start with a back four switch to three at the back as soon as they have the ball. So how did an idea that was nearly forgotten end up back at the centre of modern football?

A short history

The back three’s first great era was the 80s and 90s. Carlos Bilardo’s Argentina won the 1986 World Cup with three centre-backs: Maradona up front, a solid three behind. Back threes in those years were usually built around a sweeper: two centre-backs man-marked the opposing forwards while the sweeper stayed free behind them to clean up.

Then two things changed. Offside rules shifting in the attacker’s favour and the spread of zonal defending made a spare sweeper standing deep a luxury. On top of that, the 4-4-2 and then the 4-2-3-1 offered balanced shapes that covered both the flanks and the middle. Through the 2000s the back three all but disappeared, apart from a few Italian sides.

The comeback: Conte and those who followed

The key figure in the comeback was Antonio Conte. At Juventus, with Barzagli, Bonucci and Chiellini, his back three brought three Serie A titles in a row. At Chelsea he switched from a back four to a 3-4-3 in the autumn of 2016 and won the league, and at Inter he won the title again with the same idea in 2020-21.

Gian Piero Gasperini built a back three at Atalanta with man-oriented pressing and wing-backs constantly bombing forward. Xabi Alonso’s Bayer Leverkusen won the 2023-24 Bundesliga without losing a game, in a shape close to a 3-4-2-1. That season’s Europa League final brought the two together: Atalanta won 3-0, two back threes facing each other in a European final.

Why now? Four reasons

1. An extra player in the build-up

In modern football, opponents usually press with two players up front. Build from the back with two centre-backs and you face two pressers: two against two. Build with three and one of them is always free. That spare centre-back can carry the ball into midfield and break the press on his own. For teams who want to play out from the back, that’s a huge advantage.

2. The rise of the wing-back

There’s a big difference between today’s full-backs and those of twenty years ago. Players who can run from one end of the pitch to the other for ninety minutes, cross, and cut inside to shoot when needed are far more common now. The back three uses them better than any other system. It gives them the whole flank, so you no longer need a winger hugging the touchline in front of them.

3. Room for two number 10s

With the wing-backs providing the width, the two players up front no longer have to stay wide and can play in the inside channels, the half-spaces. The two “10s” in a 3-4-2-1 receive in the area defences find hardest to cover, between the full-back and the centre-back. In a back four you usually have to give up a winger to fit one of them in.

4. Defending the box

Without the ball, the wing-backs drop back and you have five at the back. Having three centre-backs in the box against crosses is real insurance, especially against tall strikers. And when one centre-back steps out to win the ball, there are still two behind him.

The hidden back three: start with four, play with three

Perhaps the most interesting development is the back three creeping into teams that line up with a back four on paper. Sides like Guardiola’s Manchester City and Arteta’s Arsenal start with a back four, but once they have the ball a full-back or a centre-back steps into midfield. Three stay behind, five spread out in front.

So the question is no longer “three or four?” but “how many, and when?”. Four without the ball, three with it; for some teams, the other way round. The numbers on the team sheet tell you less and less about what a team actually does.

So what are the weaknesses?

• When the wing-backs tire, the system collapses. If they can’t get back in the last half hour, a back five suddenly becomes a back three with empty flanks.
• Against one striker, a centre-back can be spare. If the opponent plays a lone striker, one of the three isn’t marking anyone. If that player can’t step out with the ball, you simply have an extra defender doing nothing.
• Two against one out wide. If the opposing winger and full-back both attack the same flank, the wing-back can be left alone against two. The wide centre-back has to step out to help.
• It needs the right players. Without centre-backs comfortable on the ball and two-way wing-backs, the back three becomes just a way of sitting deep with five defenders.

Does your squad suit a back three?

Look at your squad and ask three questions. Do you have at least three centre-backs who are comfortable on the ball? Do you have two wing-backs who can run for ninety minutes? And do your best attackers like to play out wide or inside? If you answer yes, yes and “inside”, a 3-4-2-1 or 3-5-2 might suit your squad better than a 4-3-3.

If you’re not sure, the best thing is to try it: build a back four and a back three with the same players and compare them on the pitch.