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An interesting thing happened in Croatia’s Euro 2016 qualifier on Tuesday. Manager Niko Kovac stepped out of his tactical comfort zone for the first time since he took over in late 2013: He abandoned the 4-2-3-1 he had been fervently advocating and the team lined up in 4-4-2 formation with a “diamond” in the middle.

There has been a lot of talk about how he should best utilize the strengths of his two best players, Real Madrid’s Luka Modric and Barcelona’s Ivan Rakitic. Both are playmakers, but their styles are very different. While Modric likes to dictate the rhythm by keeping the ball in movement with many passes and is very good at shielding it from the opposition, Rakitic is more attacking.

Even though he has adapted to the tiki-taka at the Camp Nou very quickly and is currently La Liga’s leader in average passes (77.9 per game, as per WhoScored; Modric is ninth on that same list, with 67.2 passes per game), Rakitic is a versatile player who can fill almost any position in midfield. He has the ability to suddenly break switch to a more direct approach, trying risky passes, shooting from distance or joining attack.

How do you fit the two of them together?

That has been the main question since day one of Kovac’s tenure. He dealt with it by playing both as the “2” in the 4-2-3-1 formation, playing without a true holding midfielder.

“I prefer the 4-2-3-1 formation and stick to it but have my own interpretations,” he said in a pre-World Cup interview for The Guardian. “The most important thing is to have players who can play both ways.”

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For him, that meant using Ivan Rakitic in a very deep position in Brazil instead of a true holder. Even though his team included two world-class playmakers, Croatia still struggled to create goal-scoring opportunities and failed to reach the knockout stages.

In the away match against Bulgaria last week, however, he fielded Rakitic in more advanced role, with Modric and Marcelo Brozovic—a hard-running, box-to-box midfielder—behind him in a central-midfield triangle. Croatia won that by a single goal but weren’t particularly convincing, and Rakitic himself wasn’t at his best.

But for Azerbaijan at home, Kovac somewhat surprisingly decided to use two players—Atletico Madrid’s Mario Mandzukic and Rijeka’s Andrej Kramaric—up front. But the really interesting part was how the players in the middle lined up.

Although it has been used since the 1960s in one form or another, the midfield diamond seems to be in vogue again these days, with Louis van Gaal’s Manchester United and Brendan Rodgers’s Liverpool its prime proponents. But perhaps the most famous usage of this formation was by Carlo Ancelotti during his AC Milan tenure a decade ago. The Italian won the Champions League in 2003 with it, managing to find the best way to fit in his two most creative players and two strikers in the lineup.

Ancelotti played Andrea Pirlo at the “base” of his midfield diamond, as a deep-lying playmaker. At the tip, as the “No. 10” was Rui Costa (later Kaka). Gennaro Gattuso and Clarence Seedorf operated at the sides, as the so-called “carrilleros” who carried the ball from defence to attack.

Niko Kovac’s tactics against Azerbaijan echoed this shape. Luka Modric was “Pirlo” and Ivan Rakitic “Rui Costa,” with Dinamo Zagreb’s Marcelo Brozovic and Internazionale’s Mateo Kovacic (injured in the first half of the game and replaced by Wolfsburg’s Ivan Perisic) in the roles of “Gattuso” and “Seedorf.”

It worked like a charm, with Croatia stuffing the visitors net in an emphatic 6-0 victory.

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Lack of width, the elemental problem with the diamond, was compensated for by collectively pressing high and blocking Azerbaijan’s ball distribution from the back. Also, both Mandzukic and Kramaric constantly pulled wide, opening space in the box for Rakitic to come into. The defence stood in high line, thus shrinking the space available for counter-attacks and the visitors, led by the experienced German manager Berti Vogts, felt suffocated from all sides.

They certainly didn’t help themselves by switching to five at the back and trying to park the bus. That only served to eliminate the one advantage they might have against the diamond—the space on the flanks—and they were also undermanned in the middle.

For Croatia fans, it was extremely pleasing to see Luka Modric and Ivan Rakitic finally functioning together in a system that seemed to suit them both very well. Modric showed exceptional vision in building from the back and was also great defensively, winning balls and intercepting passes; Rakitic was a constant threat on the edge of the box, using gaps between the lines to great effect.

The diamond looked like the ideal shape for both players. However, it might have been just a one-off.

Given the characteristics of other players at their clubs, we are unlikely to see Modric or Rakitic in the same role for Real Madrid and Barcelona, respectively. And while Niko Kovac had great success with it as an attacking formation against Azerbaijan, using two strikers and no true holder against a stronger opponent might be just too risky to try.

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