It's difficult to understand whether Switzerland are actually any good. Their opener was a topsy-turvy 2-1 win over Ecuador in which they won the match in stoppage time, having nearly lost it 15 seconds earlier. Then they were thrashed 5-2 by France, before hammering Honduras 3-0.
Therefore, it's hard to predict how much of a fight they'll put up against Argentina in the penultimate World Cup round-of-16 match, but it should be an intriguing tactical battle between two very different sides. Here are five key questions that might help decide the game:
How do Argentina re-shape without Aguero?
Sergio Aguero limped off midway through Argentina's final group-stage game against Nigeria, but the Manchester City forward has never looked entirely comfortable at this World Cup.
There are two separate problems. First, Aguero wasn't 100 percent fit anyway. When short of that level, his acceleration is less rapid, and that's the key part of his game. His movement becomes easier to track, his runs are more predictable. He's a completely different player.
The other problem is tactical. Aguero's role in this side has never been entirely certain, his space often eaten up by either Gonzalo Higuain or Lionel Messi. He positions himself somewhere in between, and defenders find him relatively easy to contain -- he doesn't offer great width, which is sometimes lacking in Argentine attacks.
His probable replacement is Ezequiel Lavezzi, who came on for Aguero against Nigeria. Lavezzi isn't as efficient in front of goal, but could provide more balance. He'll probably start on the right, and stretch the play by making runs in behind, which might afford Messi and Higuain more space -- the same way Pedro Rodriguez helps to bring the best out of others for Spain.
Can Switzerland stop Messi?
It's the most basic question when it comes to Argentina, but it remains crucial.
Strange as it might sound considering Messi has hit four goals, opponents have nullified him quite well throughout this competition. How does that make sense? Well, Bosnia-Herzegovina did an excellent job against him in the first half of their 2-1 defeat, with Muhamed Besic tracking him tightly and denying him space -- Messi would complain about the system, but it was mainly when Bosnia had to chase the game that he found space.
Iran, meanwhile, defended well for 99 percent of their game against Argentina, with Messi barely noticeable between the lines. There was just one moment of genius in stoppage time, the first time Iran didn't shut him down with two players.
Then there was Nigeria, who passed Messi around their midfield effectively, but asked Ogenyi Onazi to mark him most closely. Messi scored two goals, but one was a rebound that fell straight to him, and the other was a free kick. Nigeria can hardly be blamed for those goals, it was just Messi being brilliant. That, of course, is the problem with Messi. You can mark him brilliantly, and still be undone.
The Swiss might not mark him brilliantly, though, because they don't possess a solid defensive midfielder. Valon Behrami and Gokhan Inler are capable of scrapping, but they're more energetic all-rounders than positionally disciplined holders. Messi might find more space than in the group games.
Can Drmic and Shaqiri combine again?
The link play between Josip Drmic and Xherdan Shaqiri in the 3-0 victory over Honduras was the best this World Cup has seen. They played simple but effective combinations between a striker making clever runs and a No. 10 capable of firing from long range. It was a brilliant performance.
There were two formats to these attacks. In one, Switzerland would play a ball into the feet of Drmic, who would then immediately knock the ball back toward Shaqiri, usually first time, for the midfielder to shoot with his favoured left foot. Alternatively, the ball would be played to Shaqiri between the lines, and Drmic would immediately set off on a run into the channels, in behind the defence, and Shaqiri would provide him with a pass. They passed to one another 13 times, of which seven resulted in shots -- two were goals.
If they play that well again, Argentina won't be able to cope. Javier Mascherano has enjoyed a good tournament in the holding role, but he's sometimes left exposed by the other two midfielders, and there are still question marks about the relationship between Ezequiel Garay and Federico Fernandez -- they've looked vulnerable to clever passing. Drmic and Shaqiri could be their downfall.
Who picks up Angel Di Maria?
What is Angel Di Maria? Is he a left-winger? Is he a central midfielder? In this Argentina side, no one really knows. His job is to shuttle up and down the left flank, providing width but then getting back and helping Fernando Gago and Mascherano protect the defence. It's a highly demanding role, and few players would be capable of performing it for 90 minutes.
The unusual role means opponents can find it very difficult to track Di Maria, because there's no obvious man to mark him. In the 3-2 win over Nigeria, Argentina's opener -- a Messi rebound, after Di Maria had hit the post -- came because Di Maria made a sudden charge past Nigeria right-back Efe Ambrose, who didn't even think about stopping him. Clearly, there was confusion about who was responsible for dealing with Di Maria.
Switzerland might encounter a similar problem, and right-back Stephan Lichtsteiner hasn't performed well in this competition so far, despite consistent excellence for Juventus.
Do Switzerland's full-backs push on?
The attacking nature of the Swiss full-backs will also be important. In their 5-2 thrashing at the hands of France, both Lichtsteiner and left-sided Ricardo Rodriguez pushed too high up the pitch before Switzerland had got the ball under control in midfield, and the Swiss centre-backs were caught out repeatedly by quick French transitions.
There's little doubt this problem was fixed for the 3-0 win over Honduras, but then that wasn't the most difficult challenge -- Honduras were probably the weakest side in the competition. Argentina are a completely different proposition, and they're at their best when counterattacking quickly into space. Switzerland's full-backs, particularly Rodriguez, can cause problems, but they must be cautious they don't expose the centre-backs.