IDIOMS

acknowledge the corn

(idiomatic) To acknowledge defeat or admit to a mistake; to cop a plea; to admit to a small error but not a larger one.

Example: 1859, J. Underwood, letter to the editor, Samuel W. Cole (editor), The New England Farmer, Volume 11,
  I should like to take a job of that kind on a wager with him, or any other New Hampshire man, and if I did not come out a little ahead on the "home stretch," why then I would "acknowledge the corn," and own myself beaten.
1880, Parliament of Canada, Official report of the debates of the House of Commons of the Dominion of Canada‎,
  Will the hon. gentleman acknowledge the corn? He does not do it. He is non-committal.
1892, The American magazine‎,
  They had simply to "acknowledge the corn," round up, and — "vamoose"; then, so soon as the soldiers had gone back to the fort, there was no law to prevent their returning.