The brass ring
Definition 1 of 1
Pro Tip 1/3Idiomatic Origin
The phrase comes from carousel games where grabbing a brass ring gave you a prize; it implies a rare chance. 
Just getting to the interview stage is like reaching for the brass ring in this prestigious company.
Pro Tip 2/3Metaphorical Use
'The brass ring' represents any valuable opportunity that is hard to obtain or achieve. 
Winning this international award is seen as grabbing the brass ring in the field of architecture.
Pro Tip 3/3Cultural Ambition
In American culture, 'the brass ring' often symbolizes personal ambition and the pursuit of the American Dream. 
For entrepreneurs, creating a successful startup is like grabbing the brass ring.