Translation guide
A person or thing that is little known but unexpectedly successful or likely to succeed.
Describing a person or team in a competition who is not well-known but may win or do very well.
Direct loanword from English, widely understood in sports, business, and entertainment contexts.
彼は今回の選挙のダークホースだ。
He is the dark horse in this election.
Literally 'hole horse', originally from horse racing, meaning an unexpected winner. Used metaphorically for people or teams.
ダークホース is a direct loanword and used in general contexts. 穴馬 is originally from horse racing and carries a nuance of an underdog with long odds. 穴馬 can sound slightly more colloquial or sports-specific.
彼はダークホースとして注目されている。
He is attracting attention as a dark horse.
あの候補者は穴馬的な存在だ。
That candidate is a dark horse.
あのチームは穴馬的存在だ。
That team is a dark horse.
Literally 'eye of the typhoon', used for a person or team that causes an upset or becomes the center of attention unexpectedly.
彼女は大会の台風の目となった。
She became the dark horse of the tournament.