THE PURPOSE OF inconsequential friendlies is to allow United States head coach Jurgen Klinsmann to tinker with player selection and experiment. The bipolar nature of his team’s 4-3 win over Bosnia-Herzegovina on Wednesday showed the widespread nature of that experimentation.

The U.S. started in a 4-3-3, went down a couple early goals, then switched to a 4-4-2 and turned the tables. Bosnia stayed consistent in its 4-3-3 all game, with target man Edin Dzeko causing trouble for 90 minutes.

Bosnia’s pattern of play ran through him often, and Vedad Ibisevic ran up top with him on the right side. Left winger Senad Lulic remained slightly withdrawn but still narrow, allowing outside backs Ermin Bicakcic and Sejad Salihovic (who plays in midfield for Hoffenheim) to provide most of the team’s width.

On the other end, American outside backs Fabian Johnson and Brad Evans were often pinned in their own end because of Bosnia’s sustained pressure on the wings. Eddie Johnson and Alejandro Bedoya stayed tucked in to fill in a central gap caused by the absence of a true attacking central midfielder.

Bosnian Choreography

As the U.S. normally does, Bosnia played with two deep central midfielders who take turns advancing. The outside backs advanced early, causing the center backs to spread, which required a central midfielder to drop in between.

It looks like a 3-4-3 at times when Bosnia attacks, as the outside backs advance to join a higher central midfielder (a No. 10, playmaker type) and a box-to-box midfielder.

Both wide backs step into the attacking half of the field. The wingers stay narrow to provide support for Dzeko and allow for overlaps. Underneath, Zvjezdan Misimovic drifts side to side, into spaces to support the player with the ball.

The result is an incredibly fluid, free-flowing style of play. Eastern European clubs and nations found a lot of success playing this way in the late 1980s and early ’90s; it’s how Red Star Belgrade won the European Cup in 1991, as did Steaua Bucharest before it in 1986.

A Leader Emerges (Again)

The U.S. relied on Michael Bradley again to set the tempo and initiate attacks. He completed 92 of 100 passes on Wednesday, including three of four corner kicks.

From his deep starting position, Bradley picks out short passes to unlock gaps in the defense, followed by longer, probing passes to get in behind. His aerial through ball to Jozy Altidore on the first American goal was a perfectly weighted pass with the backspin necessary to ensure it would settle for Altidore’s run.

The gap that naturally opens up in Klinsmann’s 4-4-2, with wide midfielders staying in the channels and two forwards high, is Bradley’s wheelhouse. He can either advance into the space or play passes for players checking in.

The No. 10 role in the U.S. system is not one tasked with playmaking responsibility. Look at the difference between Bradley and Mix Diskerud’s distribution:

It makes Klinsmann’s decision to start Diskerud that much more puzzling. In this case, it’s not a knock on Diskerud, as the skills of a second forward are not naturally in his toolbox. Perhaps starting Aron Johannsson from the beginning would have been a better choice.

New Boys on Display

Speaking of the Icelandic-American, Johannsson showed promise in his short time on the field. He completed 100 percent of his passes and exhibited adeptness at finding gaps in an opponent’s defensive shape.

In this play, he stays in the hole between center back and outside back the entire time the U.S. moves the ball down the field. He’s on the weak side, and it would take something special to get him the ball with the middle clogged, but the positioning serves him well as Bosnia tries to recover.

Too many attacking players think about moving forward and not backward, but when the ball (emphasized with red dot) is chipped over the top and Joe Corona starts moving toward it, Johannsson again finds the soft spot by pulling back off the forward line.

At this point, his mind is on giving Corona a proper supporting angle to receive a pass after the winger pulls the ball out of the air.

The eventual pass isn’t great—it’s hit weakly and a little bouncy—but Johannsson maneuvers around a retreating defensive player with one deft touch and rockets a shot on target.

New center back John Brooks also played well. His biggest attribute, especially at 20 years old, is his composure. Even guarding one of the most dangerous attacking players in the world in Dzeko, Brooks handled almost every situation superbly.

Dzeko flicked over Brooks’ head for the final Bosnian goal, but it was more of a positive attacking play than a negative defensive one. Brooks also displayed good awareness of his positioning on the field, knowing when to allow a through ball to run to the goalkeeper and when to intervene on an attacker.

It’s Not About the Formation

Once again, the U.S. showed that 4-4-2 is its best formation. But it’s important to remember in the modern game that it’s not about where the players line up on the field because soccer players are much less static than they were even 10 years ago.

The U.S.’s success in its 4-4-2 is more about Bradley’s ability to penetrate from a deep-lying position and his vision while advancing the ball from those spots. He and Jermaine Jones still have some kinks to work out in their partnership—namely, Jones likes to advance sometimes when he shouldn’t—but it has emerged as the most important spot on the field for the U.S.

It’s also an evolution of the modern game that the playmaker does his work from such a deep spot. As long as Bradley stays healthy, he will play that role and likely continue to be the most important American player through the World Cup in Brazil.

Liviu Bird is ASN's tactical analyst. He is also a contributor to NBC ProSoccerTalk and is Cascadia regional editor for SoccerWire.com.