What is a dark horse in soccer?
A dark horse is an unfancied team nobody expects much from — until they start knocking out the favorites and crashing the late rounds. Every World Cup has one.
Explain further
The term itself is borrowed from horse racing, where a "dark horse" was a runner the bettors knew little about, so when it won, it caught everyone off guard. Soccer adopted the phrase for the same idea: a team with no big reputation, no superstar roster, and low expectations that suddenly goes on a run nobody saw coming. They are the side you didn't circle on your bracket who ends up ruining everyone else's.
What makes a dark horse special is the upset chain. At a tournament like the World Cup, the favorites are a small handful of usual suspects. A dark horse beats one of them, then survives the next round, and the further they go the bigger the story gets, because every win is one the so-called experts swore wouldn't happen. Real examples include South Korea reaching the semifinals in 2002, and Croatia, a country of under four million people, reaching the final in 2018 and finishing third in 2022.
Here is what trips up Americans: a dark horse is not the same as the eventual champion, or even a Cinderella that wins it all. The label is about defying expectations, not necessarily lifting the trophy. Most dark horses get knocked out eventually, but by then they have already become the most fun team in the tournament to root for.