Brazil has been FiveThirtyEight’s frontrunner to win the World Cup since the beginning of the tournament. But A Seleção will have to do it without its star, Neymar, who is out of the tournament after fracturing a vertebra in Brazil’s quarterfinal win against Colombia. In the semifinal against Germany on Tuesday, Brazil will also be without defender Thiago Silva, who was suspended after accumulating two yellow cards (Silva will return if Brazil reaches the final).
Our forecast, which gives Brazil a 54 percent chance of treating its home fans to a title, doesn’t account for these player absences. This article will attempt to measure their impact and recalculate the numbers.
We have some reasonably good news for Brazil. Even without Neymar and Silva, the team remains the leading contender to win the World Cup in our estimation. You may or may not agree with the math, but the intuition behind it is this: Soccer is a team sport, and Brazil is a very deep team. Whether Brazil is better than Germany without Neymar and Silva is up for debate. However, Brazil will play at home, where the national team hasn’t lost a competitive match since 1975.
Our rating system
Our World Cup forecasts are based on ESPN’s Soccer Power Index (SPI). SPI is essentially two ratings systems rolled into one. It measures a national team’s performance, placing more weight on its most competitive matches, and evaluates the talent on its roster based on players’ performance in national and club matches.
The player ratings work by means of a plus-minus system that assigns or subtracts points from players based on goals scored and allowed at the time they’re on the pitch. They include data from national team matches, along with the top-flight club leagues in Spain, England, Italy, Germany and France, and matches from the Champions League.
In principle, the system operates something like this. The average English Premier League team scores and allows about 1.4 goals per game. But let’s say Arsenal wins a game 3-1 instead against an average EPL opponent. Its three goals scored are 1.6 goals above the league average, so we have 1.6 goals worth of extra credit to apportion out to the players who were on the pitch at the time. Arsenal also allowed 0.4 goals less than average, so there’s 0.4 goals worth of defensive credit to split up, too.