a chance in a million

a chance in a million

An extremely unlikely chance, opportunity, or possibility. According to the tech company, there is only a chance in a million that their new facial recognition software could be fooled by a picture or someone who looks similar to you. I knew it was a chance in a million to photograph the rare bird during its mating ritual.
See also: chance, million

a ˌchance in a ˈmillion

(informal) a very unlikely possibility: If you lost your ring on the beach, it’s a chance in a million that you’d find it again.
See also: chance, million