Over the next few days, FiveThirtyEight will be examining each of the eight groups in the 2018 World Cup, which begins Thursday in Russia. Read about Group A, Group B and Group C.

Lionel Messi still has not won a senior international tournament. His Argentina was defeated by Germany in the last World Cup and lost on penalty kicks to Chile in the final of the Copa America in both 2015 and 2016. La Albiceleste will be looking to win Messi the trophy he deserves, and for the first step on that journey, the team has been drawn into an entirely winnable group with Croatia, Iceland and Nigeria.

Paper tiger or legit contender?

Like its neighbor Uruguay, Argentina’s strength resides primarily in its forward line. Manager Jorge Sampaoli will have to answer the question perennially asked of the person at the helm of Messi’s national team: Which excellent striker should play with Messi? On a purely statistical level, the answer should be Manchester City’s Sergio Aguero, whose 0.67 expected goals per 90 minutes in the last two seasons places him in the top 10 in the world.

But Sampaoli’s preferred tactics make the lineup question more complicated. Sampaoli is a disciple of the revolutionary Argentine manager Marcelo Bielsa, known as “El Loco,” who popularized a harum-scarum pressing style. And Sampaoli has Argentina playing this way, for better or for worse.

Argentina’s aggressive style How CONMEBOL teams compare in rate of high presses since the last World Cup Team Press Rate Argentina 56.2% Chile 55.2 Ecuador 50.8 Brazil 49.4 Colombia 49.0 Peru 46.3 Uruguay 45.7 Paraguay 44.1 Venezuela 42.2 Bolivia 39.4 Presses are counted when a new opposition possession is broken up before the opponent can string three passes together. Source: Opta Sports

Among the South American teams that made the world cup, Argentina relies the most heavily on an aggressive high press, breaking up new opposition possessions more than 56 percent of the time before the opponent can string three passes together. Only Chile, which both Bielsa and Sampaoli had managed previously, has similar numbers, and Chile did not make it out of the qualifying round. Argentina struggled as well and only qualified on the last day. The press can create attacking chances, but it can also leave a defense exposed if an opponent can pass through it. To effectively play such an aggressive, hard-running style, Sampaoli may opt for neither Aguero nor longtime Argentine starter Gonzalo Higuain, but rather Higuain’s club teammate Paulo Dybala, who has scored 38 non-penalty goals for Juventus in the last two seasons, playing primarily behind the striker. Dybala offers less pure goal-scoring ability than Aguero and Higuain, but he is younger and provides energy and creativity for a manager whose team must run all day long. Messi at 30 is already unable to press as he used to, and pairing him with another old striker risks blowing up Sampaoli’s plan before it gets started.

The Soccer Power Index, FiveThirtyEight’s team rating system, gives Argentina a better than 75 percent chance of making it out of the group, but only about a 7 percent chance to win the World Cup. It may take a gamble like benching Aguero and Higuain to bring Argentina back to the level of true World Cup contender.

Croatia, like Argentina, is looking to get the most out of a golden generation at one position, but the Balkan side is flush with midfielders, not forwards. Real Madrid’s Luka Modric is the superstar of the group, but Ivan Rakitic (Barcelona), Marcelo Brozovic (Inter Milan) and Mateo Kovacic (Real Madrid again) all play for Champions League sides.

What is unusual about Croatia, statistically, is that despite all this great talent in the center of the pitch, the team is quite dependent on crossing from wide areas to attack the penalty area — of all the teams at the World Cup, only underpowered Saudi Arabia relies on crosses for penalty area entries more than Croatia. Manager Zlatko Dalic likes to play two wingers, usually Ivan Perisic and one other, on either side of Modric in the attacking band. The passing options for Modric and the central midfielders are then heavily constrained to the wide areas. Croatia’s talent is probably enough to see it through, but this mismatch between talent and tactics means that Croatia may be primed for upset.

Underdog or also-ran?

If there is to be an upset in this group, who better than Iceland to pull it off? The tiny Scandinavian nation is going to its first World Cup after a Cinderella run in the 2016 Euros and a shockingly assured European qualifying season. Iceland will not be trying anything unusual or pretty, but what it does is effective. Iceland will look for quick-hitting counterattacks and set play situations. If neither of Croatia or Argentina can sort out a solution to their tactical problems, Iceland’s clear understanding of its own style should give them a real shot at an upset.

Nigeria could make an underdog run here by the same logic. Its attack is poised to hit quickly rather than play in possession, and SPI rates Nigeria’s defense as 14th-best at the World Cup. Don’t expect a great deal of excitement from the Super Eagles, but Gernot Rohr has drilled his team to play a structured defense that could give Argentina and Croatia trouble.

Player to watch

Nigeria’s defensive tactics do not work without keeping numbers back, and that places most of the responsibility for getting shots on the striker. Luckily for Super Eagles fans, their team has a player with superstar talent — if they will just let him get off the bench, where he has been stuck in recent warm-up friendlies. At the club level, Kelechi Iheanacho has had the misfortune to play behind Aguero at Manchester City and Jamie Vardy at Leicester City the past two years, which has limited his minutes, but the production is there. With about 10 expected goals and five expected assists in 1431 minutes played, Iheanacho’s rate stats compare well to young superstars like France’s Kylian Mbappe and Brazil’s Gabriel Jesus.

Europe’s top young scoring talent Highest expected goals plus assists per 90 minutes among players 22 and younger in the big five European leagues, 2016-18 Player Country Expected goals + assists per 90 minutes Kelechi Iheanacho Nigeria 0.96 Kylian Mbappe France 0.91 Gabriel Jesus Brazil 0.88 Timo Werner Germany 0.68 Ousmane Dembele France 0.68 Anastasios Donis Greece 0.62 Patrick Cutrone Italy 0.61 Ademola Lookman England 0.59 Maxi Gomez Uruguay 0.59 Leroy Sane Germany 0.58 Dele Alli England 0.57 For players with minimum 1,000 combined minutes in club and Champions League play. The big five leagues are the Premier League (England), Bundesliga (Germany), Ligue 1 (France), La Liga (Spain) and Serie A (Italy). Source: Opta Sports

While the Nigerian youngster cannot be expected to maintain these rates over a full starting season, it is hard to escape the conclusion that he could be a top striker if he got the chance. Nigeria will need a little luck and lot of work from its striker to make it out of a tough Group D. Taking a bet on a player with incredible potential at precisely the position where it is needed most could propel the underdogs to the knockouts.

CORRECTION (June 11, 2018, 1:35 p.m.): A previous version of this story incorrectly described Nigeria’s coaching staff. The current manager is Gernot Rohr, not Salisu Yusuf.

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