Football is a consistently evolving entity, with positional tweaks and systematic adjustments made each and every year in order to find a new, winning formula.

Sometimes it's a certain tactical visionary that sets a trend—Luciano Spalletti and Pep Guardiola, perhaps—but at others, change is a natural product of tactical growth.

We're in the midst of another important change in how midfielders are being classified just two years after the birth of the "suffoco"—the stifling No. 10 role that suffocates a deep-lying playmaker.

Athleticism is fast becoming a key attribute in the modern game, with players such as Kwadwo Asamoah and Arturo Vidal displaying the obvious advantages of incredible physical shape.

The tactical systems toward which teams have begun to lean—the 4-4-2, the 3-5-2 and the 4-2-3-1—require athleticism to prosper. Box-to-box roles in the first two demand an engine, while the latter formation utilises a surging defensive midfield to break games.

That "breaking" ability is what's created the newer breed of central midfield. It's not a No. 10; it's not a No. 8...it's somewhere in between.

Here we'll outline that role, how it's emerged and who displays it best.

The "Classic No. 10" and Flat CM

It's important to nail the basic nature of the two contributing roles first, as the new-breed central midfielder combines both roles to great effect.

The flat central midfielder, epitomised by Gareth Barry in his days at Aston Villa, is a well-rounded player who sits happily in a flat 4-4-2 formation. He's defensively aware and creative on the ball and boasts excellent awareness of what's going on around him, be it transitions, counters or possession periods.

The position was very common throughout the 1990s and 2000s in the English Premier League and generally spawns anywhere the 4-4-2 dominates.

The No. 10 is a far more complex role that varies greatly depending on which country you're in: In Argentina, it's the Juan Roman Riquelme "enganche," sitting in and controlling play from behind the forward; in Brazil, it's the dynamic Ronaldinho, drifting into space; in Italy, it's the trequartista, acting as a second striker or support striker.

The responsibilities of the position differ from continent to continent, but the general area into which the player gravitates is the same.

The two roles have become night and day to each other—Riquelme couldn't play Barry's role, and Barry would struggle in Riquelme's—but the newer central midfielder role combines elements of the two superbly to make a complete player.

The Hybrid CM/AMC

Typically speaking, new positions are borne from changes to tactical culture.

The false No. 9 was different. That was innovative (or insane) and revived after years on the scrap heap, but most advancements—particularly widely adopted ones—are the product of natural change.

The 4-2-3-1 formation has been the "king" of football for three or four years now, with a combination of the 2010 FIFA World Cup and Jose Mourinho's treble-winning Internazionale side displaying its merits to a global audience.

But football is steadily moving away from it as the de facto best option, with the 4-3-3 and 3-5-2 in particular looking extremely likely to overtake it. As a result, the "hybrid CM" role has come to the fore.

Moving away from the 4-2-3-1—a system that incorporates a classic No. 10—means moving away from a player who plays a traditional game between the lines.

In a 4-3-3, one of the three midfielders holds, one steadies and one breaks forward. It's the latter option we're referring to here, and he must incorporate a complete skill set in the modern game.

During the Under-21 European Championships, we saw Thiago Alcantara move away from a steadier, Xavi-esque role and take players on in midfield. We thought he was a passing metronome, but he's proved to be a far more dynamic outlet.

WhoScored measured him at 2.2 take-ons per game completed, with three goals, one assist and a 93.2 percent pass completion. He was committing defenders and moving forward with the ball at his feet in impressive fashion—a fashion that, perhaps, we didn't know he could pull off.

Thiago is just the tip of a rising iceberg.

Prime Examples

Cesc Fabregas, Barcelona

David Ramos/Getty Images

The hybrid CM/AMC role demands a certain element of verticality, and it's no surprise to see Cesc prospering in Gerardo Martino's typically Argentine system.

He's begun eating into Andres Iniesta's minutes on the pitch, taking the key role in Tata's 4-3-3 and storming forward to wonderful effect.

The Spaniard can keep possession and tempo as well as anyone else, but given the chance to thread Neymar and Lionel Messi through or break forward himself, he'll take it.

Toni Kroos, Bayern Munich

EuroFootball/Getty Images

Kroos is probably one of the most grossly underrated players in world football, and it's easy to see why summer speculation of the German being dropped in favour of Thiago upset Die Bayern's fanbase.

Kroos is monstrous and complete, and he plays a hybrid role in Guardiola's 4-1-4-1 (4-3-3) system. He's physically overpowering, passes well, dribbles superbly and boasts one of the finest long shots in the game.

He can play holding midfield, flat CM, hybrid CM and No. 10—you'll struggle to find a more well-rounded player than Kroos.

Oscar, Chelsea

Shaun Botterill/Getty Images

Despite managerial hoopla, formation changes and hirings and firings, Oscar is one of the most consistent performers in football. That's down to his incredible versatility and firm grasp on the tactical aspect of the modern game.

Oscar has played almost every role in midfield now, and while he excels as a No. 10, he put in superb showings as a hybrid CM under Mano Menezes for Brazil.

The Olympic games saw the Selecao field a 4-3-3, and the Chelsea star was brilliant, showcasing his all-round skill set to great effect. Oscar's wide range of talents is the reason Jose Mourinho has frozen out Juan Mata.

What to Look For

The three examples listed are prime, world-class players who are fulfilling this role in plain view of the world, but it's not as specialist as other trends that filter through.

It's happening everywhere, with Aaron Ramsey, Fabian Delph and Tom Cleverley another three names a little closer to home taking on the responsibility.

Ross Barkley, Everton's young English prospect, is currently settling into a No. 10 role at Goodison Park, but given his skill set, build and playing style, expect to see him drop back into this sort of position to great effect.

The rise of the Yaya Toure/Fernandinho surging defensive midfield mould was linked to the establishment of the 4-2-3-1 formation as the go-to system. The rise in the hybrid CM/AMC mould will lead to the rise of another, but is it the 4-3-3, the 4-4-2 or the 3-5-2?

Follow @stighefootball