In a decade, soccer's biggest tournament is set to become even bigger.

FIFA, the game's governing body, unanimously voted to expand the tournament to 48 teams from 32 teams starting in 2026.

The new format starts with the 48 teams playing one another in 16 groups of three. Then, the top two teams from each group will advance into a 32-team group for the knockout stage.

"We are in the 21st century and we have to shape the football World Cup of the 21st century," said FIFA President Gianni Infantino, who had promised to expand the number of World Cup teams during last year's election to replace Sepp Blatter.

Of the 211 member associations in FIFA, "135 of them have never played at a World Cup," according to Reuters.

The change will help develop the game and expand its reach, Infantino said. He added: "Football fever that you have in a country that qualifies for the World Cup is the biggest promotional tool for football that you can have."

The expansion is also a money-maker — "FIFA forecasts the equivalent of $1 billion extra income at current rates from broadcasting and sponsor deals, plus ticket sales," according to The Associated Press.

And, rebuffing criticism, Infantino said the new format will take place in the same number of days as the previous one, 32, thereby not adding to the time that clubs would need to release players. The tournament will also be played in 12 stadiums, as it is currently.

Some powerful stakeholders remain opposed. The European Club Association said the "regrettable" decision was based on "political reasons rather than sporting ones and under considerable political pressure."

Critics such as The Independent's chief sports writer argue that adding more teams will reduce the quality of play. "The prestige attached to World Cup qualification will be watered down at a time when international football is already fighting a losing battle for relevance in the face of the club game," he writes.

But others say the change presents exciting opportunities, such as ESPN:

"The positives ought to be obvious. You would have far fewer dead rubbers (provided the top seeds play first). You would have another round of knockout games, which tend to be more tense because the stakes are higher. Most of all, you would turn the game's global showcase into a truly global event, offering a greater shot to countries who would otherwise only watch it on TV."

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