The 4-2-3-1 formation has become the de facto best option for most top clubs in world football.
There are some exceptions—such as Barcelona's 4-3-3 and Juventus' 3-5-2—but the lion's share of teams making a splash or looking to do so utilise this handy system.
It rose to prominence largely thanks to Jose Mourinho's use of it in 2010, but astute managers had tried something very similar beforehand: Sir Alex Ferguson, for example, fielded Ryan Giggs, Wayne Rooney, Cristiano Ronaldo and Carlos Tevez in a 4-2-3-1-esque shape in 2008.
Euro 2012 set the scene for every other manager to sit up and take notice: half the teams participating used the formation, including hosts Poland and semifinalists Germany.
So why is it so useful, so popular and so common for teams to apply it at the moment?
In international football the answer is pretty clear: the player roles are clearly defined, masking the fact that players have little time to train together. Midfielders, wingers, defenders and strikers all know their default job, and due to the vast area of the pitch the system comprehensively covers, it's quite a safe shape to use.
But in domestic football, where coaches have the luxury of choice and time on their side, clubs are still reverting to this as the now-default formation.
What's remarkable about the system is, unlike so many others, it's amazingly versatile.
Our first example comes in the form of the recently victorious and much-lauded Borussia Dortmund, who have lit up the UEFA Champions League this season and remain unbeaten as they head into a semifinal second leg at the Bernabeu.
The 4-2-3-1 formation Juergen Klopp sets out is fast-paced, exciting to watch and highly effective in its goals. They can dominate possession through playmaker Ilkay Gundogan, thread killer-balls from defence with Mats Hummels or lead quick counterattacks through Marco Reus.
Klopp's men have rinsed Bayern Munich several times in the last few seasons, securing back-to-back domestic titles and smashing the Bavarian outfit 5-2 in the DFB Pokal final.
The full-backs are inherently attacking and link superbly with the front man, while the holding midfielders are skilled in every area of the game; Sven Bender is one of the best run-trackers in world football, while Gundogan can seemingly do a bit of everything.
Jakub Blaszczykowski puts in a workman-like shift on the right and contributes at both ends of the pitch, while mercurial No. 10 Mario Goetze can be the difference in any game.
Klopp has been lauded for his bold tactics, and in particular his decision to move the playmaker spot from player to play depending on the game. If Gundogan gets space, he will control the tempo and launch Reus in behind; If he's cancelled out, Goetze takes control.
The fluidity and quickness at which BVB are able to move wowed many who tuned in to watch them maul Real Madrid on Wednesday, and a first-time football fan could feasibly bottle that performance and believe the formation they used is nothing other than all-out attack.
But that's not so, and when you take a second to consider how others use the very same system, it's startling to think how versatile it is.
Take Malaga, for example, the team BVB actually played in the quarterfinals.
Coach Manuel Pellegrini has sculpted one of Europe's best defensive outlets this season led by the formidable Martin Demichelis. Los Boquerones kept 10 clean sheets in their first 18 league games, while they also navigated their first three Champions League games without conceding.
It's the very same shape—the 4-2-3-1—but it's natural actions, default reactions and attacking tendencies are very, very different.
Pellegrini has played to his side's strengths, and the 0-0 matchup against Dortmund at La Roselada showcased just how different footballing approaches can be.
Ignacio Camacho and Jeremy Toulalan formed a solid holding midfield pivot, moving laterally in unison and sticking deep to shield their defence. The tenacious Camacho did a wonderful job matching Goetze physically, while he also sensed the right time to drift out and close off Reus very efficiently too.
Key playmaker Isco works primarily from the left, and he shoulders plenty of responsibility in dragging his side up the field; He either takes it and runs or plays closely off a true target man in Julio Baptista.
Rather than flood forward like Dortmund, Malaga attack with care and due diligence—it's rare you'll see more than five players committed to an attack and both the holding midfielders remain reluctant to travel forward.
The fact that Dortmund and Malaga were matched together in the quarterfinal was enticing, as the opportunity to see "who uses the formation best" was always going to make for exciting football (analytically speaking).
The result was chaos, but the 180-minute sample is enough to prove how differently things can be done with the same ingredients.
Manchester City use a 4-2-3-1 on most occasions, but rarely do they field players who can bring the side true width. The "central wingers" Roberto Mancini prefers start narrow for possession's sake and then drift wide in an attempt to find space, whereas Klopp has "Kuba" sticking touchline wide all the time.
While Samir Nasri and David Silva "float" between the lines and attempt to drag the full-back inside and meet them head-on, Scott Sinclair—a true chalk-on-your-boots wide man—sits on the bench getting splinters.
Paul Lambert uses the 4-2-3-1 with Aston Villa in different ways on a week-to-week basis: against Stoke City Ashley Westwood controlled the middle of the park like a metronome, while against Manchester United he focused on early balls into the wide areas from his speedy wingers to capitalise on.
Jose Mourinho's Real Madrid can dominate most fixtures and come out five goals to the good, but when they face Barcelona, they have but one objective: Give Xabi Alonso the ball and let him play a diagonal for Cristiano Ronaldo to run onto.
Same formation, but the game plans are chalk and cheese.
With coaches trying desperately to stay one step ahead all of the time, the flexibility and almost unlimited possibilities the 4-2-3-1 brings makes it an invaluable tool.
As long as coaches continue to manipulate and find ways to extract different game plans from the same system, it's not going anywhere fast.