have an eye for the main chance

have an eye on/for/to the main chance

To be continuously seeking opportunities to advance oneself or make money. The term often refers to someone who is ambitious without consideration of others. Primarily heard in UK, Australia. You just have an eye on the main chance—you don't care if I succeed or fail.
See also: chance, eye, have, main, on
Farlex Dictionary of Idioms.

eye to the main chance, have an

Look out for one's own best interest. For example, Tom is watching the company's progress very closely; he always has an eye to the main chance . [c. 1600]
See also: eye, have, main
The American Heritage® Dictionary of Idioms by Christine Ammer.

have (or with) an eye for (or on or to) the main chance

look or be looking for an opportunity to take advantage of a situation for personal gain, especially when this is financial.
This expression is taken from the use of main chance in the gambling game of hazard, where it refers to a number (5, 6, 7, or 8) called by a player before throwing the dice.
See also: chance, eye, have, main
Farlex Partner Idioms Dictionary

have an eye to/for the main ˈchance

(British English, usually disapproving) be good at using opportunities for your own benefit: She’s certainly got an eye for the main chance. Her business has become highly successful.
See also: chance, eye, have, main
Farlex Partner Idioms Dictionary

eye for/to the main chance, to have an

To look out for one’s own best interest or for the opportunity that will be most profitable. The term is thought to come either from betting in cockfights (main being an obsolete word for cockfight) or from a game of chance called hazard, in which the main signified the number (anywhere from 5 to 9) called by the caster before the dice were thrown and chance signified the second throw of the dice, which determined the total. In any event, the expression dates from the sixteenth century, was recorded by John Lyly and Shakespeare, among others, and appeared in John Ray’s English Proverbs of 1670.
See also: eye, have, main
The Dictionary of Clichés by Christine Ammer
See also:
  • an eye for the main chance
  • an eye on/for/to the main chance
  • for (one's) (own) sake
  • for sake
  • keep (someone or something) in sight
  • keep in sight
  • keep sight of
  • keep sight of (someone or something)
  • keep sight of somebody/something
  • leave oneself wide open for