Talking Tactics: Mauricio Pochettino's poor defensive structure, overreliance on Christian Pulisic and pressing nightmare doomed the USMNT against South Korea

It's first worth examining what, exactly, happened on against South Korea. The obvious answer is that, well, the U.S. lost. They didn't score. They had four chances, and conceded two fairly preventable goals. Son bagged the first inside 20 minutes. Lee Don-Gyeong added a second on the stroke of half time.

Korea spent the next 45 minutes sitting back, occasionally hitting on the break, but mostly watching as the U.S. tried various things but created no clear cut looks on goal.  Pochettino did a pretty good job of breaking the USMNT social media sphere after the final whistle by claiming that his side were "better" than South Korea.

And in some ways, it's easy to see the logic there. The U.S. had more shots. They had more of the ball. In the last 20 or so minutes, with a few tactical tweaks, they looked the more likely team to score. A couple of nice saves saw Folarin Balogun - a clear bright spot on the night - denied of what would have been a potentially game-changing late goal.

But that summary misses the wider point: Pochettino's men were outcoached and outplayed. 

The U.S. lined up in what looked loosely like a 4-2-3-1. Matt Freese was in goal. Sergino Dest and Max Arfsten played in the fullback slots. Tim Ream - 37 and getting older - partnered with at centerback with Tristan Blackmon, who at 29 was making his first senior team start - and was out of his depth at the international level.

In front of them sat Tyler Adams and Sebastian Berhalter as a double pivot of sorts - although Berhalter pushed a little higher up. An attacking trio of Tim Weah, Diego Luna and Christian Pulisic offered creativity, while Josh Sargent - who, in case you haven't been paying attention, has not scored a USMNT goal for a long time - was handed the starting job through the middle.

There were, admittedly, a couple of puzzling picks. Throwing Blackmon into the fire against the electric Son seemed odd. Berhalter, too, was a curious call. And though Sargent has been on fire for Norwich, Balogun would seem the better option through the middle. Team selection notwithstanding, though, this was a system issue.

When the U.S. had possession, it was clear that there was a policy - get it to Christian Pulisic. There is nothing wrong with that. Pulisic is a unique talent, the best player in this side, and perhaps the most accomplished footballer to ever wear a USMNT kit. Ghosts of summers past can be exorcised here.

Pulisic is the main man and should be treated as such. He started on the right, but drifted everywhere, dropping into pockets of space and asking for the ball. It is no surprise that he ended the game with 76 touches. Luna and Weah managed 78 combined. 

Everyone else, in such a system, has to move around him, show for passes, find the best angles and create the right spaces by moving cleverly off the ball. It was something that Dest, admittedly, did a fine job of in his return, holding width, darting into the box, and playing some tidy combinations. Everything else, though, was frightfully static.

Luna and Weah had nowhere to go. Sargent relies on having the ball in the air. Berhalter and Adams - both agreeable passers of the ball - didn't shuffle it forward quickly enough. The result was Pulisic constantly dribbling into traffic, and muted by a well-drilled Korean back five. 

The USMNT's four best chances came from a set piece, a lackadaisical turnover, a moment of individual inspiration from Dest and a freak rebound into Balogun's feet. None of those looks offered a clear, coherent state of play. 

But perhaps more worrying was the lack of clarity off the ball. Part of the calling card of Pochettino when he was hired was his affinity for high-pressure, exciting soccer. It was, after all, why many fell in love with his Tottenham team in the Premier League. Spurs were a nightmare to play against because they always wanted the ball, and fought relentlessly to win it back.

Led by the pressing of - and this one hurts - Son, Pochettino pieced together a pressing machine. Off-ball structure isn't flashy, but it's what wins games. Many assumed that Pochettino's side would bring the same kind of swagger and verve to international soccer.

It was certainly possible. Pochettino has a group of tactically intelligent players. The U.S. are athletic enough, in theory, to be able to execute this kind of thing. But there were some early warning signs that this might not be the off-ball-soccer-hipster-fairytale that some dreamed of.

In Pochettino's first fixture in charge - a 2-0 win over Panama - the USMNT looked loose at times. Pulisic didn't seem to know when to press and when to drop. On a few occasions, he was simply caught flat-footed, in the middle of nowhere. A better side would have punished them. It's a trend that has continued since then.

It's how Panama snagged a late win in the Nations League semifinal in March, and was also exploited by Mexico in the Gold Cup. And it showed up on Saturday, too.

This is where it can get dry. To vastly oversimplify things, there are, typically, and very generically, three options for defending off the ball.

The first is to press high, commit as many men forward as possible, and cut off all passing lanes. That typically means putting all 10 outfield players in the opponent's half, asking the goalkeeper to come off his line to "sweep" and trusting that the defensive line will be brave enough to step up and give up, effectively, half of the field for the opponent to exploit. This is typically what you do if you are a better team against an opponent that likely won't do much with the ball. 

The second is a low block. It's the whole Jose Mourinho thing - sit in, allow nothing in behind, squeeze spaces. The third is a "mid block",which is sort of a combination of the two. It requires a certain amount of pressure on the ball, but doesn't rely on man-to-man, out-and-out "pressing" in a typical sense.

But the crucial piece of a mid block is to ensure, at all costs, that the three lines move coherently. If the defense steps up, so does the midfield, if the attackers push, so does everyone else. No one breaks lines outright, and everyone knows which lanes to cut off - without charging for the ball. 

In theory, the U.S. try to play a mid block. No one overcommits, but no one drops back. The defensive line pushes up, but doesn't play recklessly. On Saturday, that system broke down altogether on a handful of occasions - and led directly to the two South Korea goals.  On the first, Pulisic didn't track back. Then Blackmon stepped. Son ran in behind and scored.

On the second, neither center midfielder stepped to an open man. A quick interchange around Ream finished with a fine backheeled finish.

There were some positives, broadly. There is a real danger in confusing formation and system. Managers can play in a similar "way" but with different personnel. For the vast majority of coaches, general principles transcend the exact configuration of the 11 guys out on the pitch. Pep Guardiola, for example, famously has a coaching bible of "possession, position and play" - three tenets that are applied to whatever formation he deploys.

It is, in fact, occasionally a bad thing when coaches turn to formations to solve underlying issues. Still, they can offer at least some short-term fixes. Halfway through the second half, Pochettino elected to change to a formation that looked more like a 5-3-2 out of possession and 3-4-1-2 with the ball. During that period, he also introduced Balogun and added an extra centerback.

The result was a more expansive side, with more creativity from wide areas. And that would make sense. The U.S. showed extra attacking intent, had an extra man on either wing, and a center forward more willing to run into space. Many have pointed out that the US could benefit from that sort of setup for some time now.

The team is heavy on center midfielders and No. 10s, has two gifted attacking fullbacks in Antonee Robinson and Dest, and, when everyone is fit, plenty of bodies for cover in central areas. Pochettino tried it, and, for a few brief minutes, it worked. The manager speculated it could be an option for the future, too.

"South Korea and Japan play in a similar way," he said on Monday. "Using the same system was a great opportunity for us to start to approach with back four and how we are going to create the dynamic to play in the opposite half, in how we build from back and all the aspects of the game. But also Japan, maybe. That was 30 minutes. Maybe we can use it during the game, or maybe we can start. We don't know. Well, we do know but we cannot tell you."

But whether that is a long-term solution remains to be seen. Pochettino has said the U.S. are basically just tweaking their side ahead of the World Cup. Results, we are told, do not matter now, but he can guarantee that they will start to mean something when the first whistle is blown next June.

There isn't necessarily anything wrong with that assertion. In fact, saying you want to win games at a World Cup is actually a rather good thing. But the issue is, it's hard to imagine that happening both short- and long-term while the tinkering is still happening. Pochettino, for his part, has insisted that experimentation is fine.

"This is one of the opportunities that we have because we are already qualified, to do this type of thing, because, if you are playing qualification games, you cannot do some tests or change too much," he said. "Sometimes, though, you need to take some risks with players that maybe are on the limit of being called, or not to be called. That can be a good or bad thing, when you are already qualified for a World Cup."

Japan will be tough. They are a better side than South Korea, and offer far more going forward. If there are new ideas to be implemented, then Japan aren't a kind team to roll them out against.

Pochettino can make all of the claims he wants about trying new faces, tinkering with formations, and getting closer to seeing a complete performance. But the fact is that the USMNT  less than 10 months from a World Cup and still don't have a clearly defined playing style. Unless that changes, it's difficult to see the U.S. making any noise on home soil.