In 2014, Atlético Madrid won one of the most improbable league titles in modern football history. It was the first time a club beyond Real Madrid and Barcelona had won La Liga since Valencia in 2004. A year earlier, Atlético had finished behind Barça by twenty-six points. The two giants, who each operate on a budget about two times bigger than Atlético’s, both broke the hundred-goal barrier, but floundered in La Liga for various reasons: Madrid had appointed cup specialist Carlo Ancelotti and duly won the Copa del Rey and the Champions League; Barça went stagnant under Gerardo Martino, and Lionel Messi, sidelined for two months between November and January, had one of his worst seasons, playing thirty-one league games, recording eleven assists, and scoring a mere twenty-seven goals.

But the scalp would not have been possible had Diego Simeone not had an intimate understanding of his squad’s qualities—and limitations. Possessing a fraction of Barça and Madrid’s talent, El Cholo built an armour-plated 4-4-2 based on deep defending, a narrow midfield, counter-attacks, blood, sweat and tears. They scored seventy-seven goals—twenty-seven fewer than Madrid—but shipped twenty-six. Like the current Premier League leaders, Leicester City, they thrived on a mixture of a quaint formation, herculean industry and strategic concepts whose roots could be traced back to Italy.

Claudio Ranieri was born in Rome and had a modest career as a defender, predominantly spent in Catanzaro, on the Italian south coast. He started managing in the mid-1980s, and proceeded to lead teams such as Napoli, Fiorentina, Parma, Juventus, Roma and Internazionale. Abroad, he coached Valencia, Atlético, Chelsea, Monaco and Greece. Earlier this season, he described Leicester as a fusion of English spirit and Italian tactics.

Simeone grew up in Buenos Aires and first moved to Europe when signing for Pisa, at twenty, in 1990. After spells at Sevilla and Atlético, he joined Inter and Lazio, winning the scudetto in 2000 under Sven-Göran Eriksson. His managing career started back home, where he won league titles with Estudiantes de La Plata and River Plate, but his first stop in Europe was again Italy, where he saved Catania from relegation to Serie B in 2011. Simeone would later describe that period as the most important of his career. In 2013, Porto coach Paulo Fonseca called Atlético “an Italian team playing in the Spanish championship”. Simeone rejected this at the time, but later said that “in terms of courage and ideas, a lot about my Atleti comes from Italy”.

The 4-4-2 has been viewed as a fossil over the last ten years, mainly because of how its two strikers leave the midfield vulnerable and outnumbered. But its initial secret was of the defensive kind. When Arrigo Sacchi installed it at AC Milan in the late 1980s—outsmarting opponents with an aggressive offside trap, zonal marking and small distances between the lines—No10s struggled to find time and space. The Sacchi school was an adventurous departure from the man-marking five-man defences prevalent in Serie A, but its main message centred on solid team shape. The system would inspire many coaches, such as Rafa Benítez, the Valencia boss in 2004. “Four-four-two is the best defensive system that exists,” Ancelotti, who was Sacchi’s regista at Milan and later his assistant for Italy, said in 2014. “Four-three-three doesn’t give the balance required and it’s more difficult to pressure higher upfield. Our intention is to defend with a 4-4-2 and attack with a 4-3-3.”

The anatomies of the 4-4-2s used by Simeone and Ranieri are comparable. Both teams tend to stay deep, with the lines positioned between twenty and fifty yards. Particularly at Atlético, the wingers tuck inside to form a tight-knit midfield four that cuts off potential passing angles centrally. (A Spanish journalist once called Simeone’s team “denser than stone”.) In both sides, the strikers drop down to disturb the opposition’s deep-lying central midfielders, a move that allows their own ball-winners to fall back and protect the defence. A pedant might call it 4-4-2-0. Going forward, long balls fly over the top, into the channels and down the flanks. Atlético won their title with a possession average of 49.1 percent, the ninth highest in the league, while Leicester currently have the third lowest average, with 43.9 percent, and the worst pass completion rate, with 69.5 percent.

The types of players are also similar. In that 2013/14 season, the typical Atlético line-up was Thibaut Courtois—Juanfran, Miranda, Diego Godín, Filipe Luís—Arda Turan, Gabi, Tiago, Koke—David Villa, Diego Costa.

With that, they had a solid goalkeeper (Courtois)—two dynamic full-backs (Juanfran, Filipe Luís)—two combative centre-backs that were strong markers and diligent tacklers, if not the most technical (Miranda, Godín)—an unpredictable right-midfield playmaker who stood out as the slickest dribbler (Turan)—two ball-winning central midfielders (Gabi, Tiago)—a right-footed left midfielder who was not the quickest, but who fed the strikers with early passes over the top; and who played the most crosses and key passes (Koke)—a defensive striker who scored just thirteen league goals, but who was invaluable in harrying and closing down players (Villa)—and a quick striker who took on defenders, worked the channels and scored most of the goals; twenty-seven to be precise (Diego Costa). They made more tackles than any other side in the league. Incidentally, their top three tacklers were their left-back (Filipe Luís) and the two central midfielders (Gabi, Tiago).

For Leicester, the most used team this season has been Kasper Schmeichel—Danny Simpson, Wes Morgan, Robert Huth, Christian Fuchs—Riyad Mahrez, N’Golo Kanté, Danny Drinkwater, Marc Albrighton—Shinji Okazaki, Jamie Vardy.

With that, they have had a solid goalkeeper (Schmeichel)—two dynamic full-backs (Simpson, Fuchs)—two combative centre-backs that are strong markers and diligent tacklers, if not the most technical (Morgan, Huth)—an unpredictable right-midfield playmaker who stands out as the slickest dribbler (Mahrez)—two ball-winning central midfielders (Kanté, Drinkwater)—a right-footed left midfielder who is not the quickest, but who feeds the strikers with early passes over the top; and who plays the most crosses and key passes (Albrighton)—a defensive striker who has scored just four league goals, but who is invaluable in harrying and closing down players (Okazaki)—and a quick striker who takes on defenders, works the channels and scores most of the goals; eighteen so far, to be precise (Vardy). They have made more tackles than any other side bar one in the league. Incidentally, their top three tacklers are their left-back (Fuchs) and the two central midfielders (Kanté, Drinkwater).

For Simeone and Ranieri, the attacking mechanisms are not overly complicated. The essentials are a solid shape and a fervent work ethic. “You don’t need so much time to understand my philosophy,” Ranieri told The Guardian last November. “It is to improve the tactical side, because I am Italian and for an Italian tactics are fundamental, but I love the English spirit. My idea about football is to play well, but even if you can’t always play well, one thing I want is your character, your spirit. That is all I can ask of you.” He added: “I ask my players: ‘We have to play like we are desperate—not every match; every second… The day my players relax, I get crazy. They know that. I think I am a nice man, but also I am demanding.”

This mindset may denote an awareness that, for all the value of tactics, a dip in intensity could derail the season. “If we slow down, it’s not Leicester, it’s another team,” said Ranieri, who has pleaded with his players not to look too far ahead. A similar warning came from Simeone towards the end of 2013/14, when a title tilt looked less unrealistic for each week. “Game by game is the life of the man on the street, day by day,” Simeone said. “We see ourselves reflected in society, in people who have to fight to keep going. As soon as we stop fighting, we have no chance.”