Where does the phrase "You're a dark horse" come from?

Answer 1

Its from the "dark ages", years ago.

Its a common fact that "dark horses" are more secret and have a better time than their lighter coloured counterparts.

So observers of horses noticed this and one of the offical horse observers of the time was down the pub or "tavern" as it was called back then, talking to his mate, Harry.
Harry was saying that he often had a good time with a local lass and as this was previously unknown to the offical horse observer he casually said "your a dark horse".

This is believed to be the first noted use of this phrase.

Answer 2

A dark horse

Meaning

Someone who emerges to prominence; being previously little known.

Origin

This was originally horse racing parlance. A dark horse was one that wasn't known to the punters and was difficult to place odds on. The figurative use later spread to other fields and has come to apply to anyone who comes under scrutiny but is previously little known.

Benjamin Disraeli provides the earliest known reference to the phrase in The Young Duke, 1831:

"A dark horse, which had never been thought of ... rushed past the grand stand in sweeping triumph."

The figurative use seems first to have been taken up when referring to the candidates for academic preferment:

The Saturday Review, 1860 - "A Headship ... often given by the College conclaves to a man who has judiciously kept himself dark."

Sketches from Cambridge, 1865 - "Every now and then a dark horse is heard of, who is supposed to have done wonders at some obscure small college."

Taken from phrases.org

Answer 3

A dark horse is a political candidate who is nominated unexpectedly, or any other underdog.

Dark Horse may also refer to:

Dark Horse (astronomy), a large dark nebula
Dark Horse (album), one of George Harrison's solo albums
"Dark Horse" (song), a song by George Harrison
Dark Horse (film), a 2005 movie by Dagur Kári
Dark Horse Comics, a comic book publisher
Dark Horse Records, a recording company owned by George Harrison
Dark Horse Brewery, a brewpub in Marshall, Michigan
Dark Horse (1992 film), a 1992 movie by David Hemmings
The Dark Horse (film), a 1932 movie by Alfred E. Green
Dark Horse (novel), a novel by Fletcher Knebel
The nickname of the 3rd Battalion 5th Marines

Answer 4

This metaphoric expression originally alluded to an unknown horse winning a race and was so used in a novel by Benjamin Disraeli (The Young Duke, 1831).

Answer 5

"A dark horse candidate is one who is nominated unexpectedly, without previously having been discussed or considered as a likely choice. ... This metaphoric expression originally alluded to an unknown horse winning a race and was so used in a novel by Benjamin Disraeli (The Young Duke, 1831)."

Answer 6

during a horse race, a horse was running that had no chance of winning, but somebody said, look out for the dark horse!. and it stuck after the horse won..

Answer 7

horse racing the one that was not expected to win

Answer 8

no im not