So close

 A simple Sudoku game.  Put a number from 1 to 9 in each empty square, but without duplicating that number in any row, column, or larger square of nine individual squares. I’ve got a particular game this far.  So close.  How hard could it be?  We could trial and error the remainder; it wouldn’t take long, but is there a solution that doesn’t require that initial trial and error guess?