Ever since Walter Mazzarri started work on his three-man defensive project at Napoli, Serie A managers have sporadically attempted to adopt some of its principles.
It then spread to England, Argentina and, finally, to the international footballing scene. While Mazzarri has gone one further and developed a 3-5-1-1 in the wake of Ezequiel Lavezzi's departure to Paris Saint-Germain, the two main strands of the three-man defence remain the 3-4-3 and the 3-5-2.
Bleacher Report takes a look at the differences between the two systems and looks into why some managers choose one or the other.
By and large, the 3-5-2 is the more popular of the three-man systems.
The likely reason for this is that the formation retains three central midfielders, allowing a holding pivot or a single destroyer behind two prototypical central midfielders.
In addition to a midfield trio, the formation also allows a striking partnership; The 3-5-2 allows a rare combination of possession-based football and duel strikers.
The wide battle is simultaneously won or lost by the wing-backs, who are required to put in a titanic shift each game to ensure their team do not end up playing a narrow, fruitless game.
Under pressure, the formation shrinks into a 5-3-2, while on the attack it can resemble a lopsided 3-3-4.
The two formations are similar: They both house three centre-backs and have a presence up top; they both hinge largely on the successes of failures of their respective wing-backs.
When a formation fails to win a wide battle, it has to change. Case in point, Mircea Lucescu's Shakhtar Donetsk ditched the 4-4-2 diamond, which hinged on its explosive full-backs, when Darijo Srna and Razvan Rat lost the wide battle against AC Milan in 2008.
That's where the 3-4-3 comes in—you've got wing-backs and wingers. With four players situated into the wide areas, you equal the amount usually found in a 4-4-2, a 4-2-3-1 and a 4-3-3.
This means the battle to stay touchline wide doesn't hinge upon the left- and right-wing-backs, and if it's not going their way, the wingers can join in.
It's arguable that, after the wing-backs, the wingers have the most important roles in the 3-4-3.
Take Roberto Martinez's Wigan Athletic as an example. Jean Beausejour does great work on the left-hand side and gets the chalk on his boots, drawing the opposing full-back all the way out or else he allows a free, unchallenged cross.
When the full-back is drawn across, Shaun Maloney—the left-winger—dips into the pocket of space, usually on the corner on the penalty area, and has time to get his head up.
This gives Maloney the playmaker role in an unorthodox position, allowing him drift inward if his colleague has won the wide battle, or drift wide and help if he hasn't.
A lot of Wigan's goals are scored from outside the area—when you look at how they play, this is no surprise. The wing-backs give them space, and when a Premier League player has time and space, he can do anything he wants.