leave to chance

leave (something) to chance

To resign oneself to something's outcome being determined forces outside of one's control. My boss always scrutinizes the smallest details of any deal she makes—she says there's nothing more foolish than leaving things to chance in business. You could just pick a few different investments and leave the whole process to chance, or you could let our firm plan your investments meticulously in order to maximize your return.
See also: chance, leave
Farlex Dictionary of Idioms.

leave something to chance

to allow something to be settled by chance. Plan your day. Don't leave anything to chance. It is not a good idea to leave any of this to chance.
See also: chance, leave
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • leave (something) to chance
  • leave (something) to fate
  • leave (something) to luck
  • replace
  • be replaced by (someone or something)
  • be replaced with (someone or something)
  • disappear without (a) trace
  • trace
  • vanish without (a) trace
  • establish
References in periodicals archive
But who runs the Lottery is too important to leave to chance and too important to leave to people few have confidence in.
Sunday Mirror Comment: Numbers up for all these lottery flops
"It seems it's far too important to leave to chance or indeed to men.
GIRLS WANT TO LOVE IN SIN; 86% favour sex before marriage