Hard work is pointless — but it's where setters begin (4)
I believe the answer is:
grid
But I can't explain it at all! Could you help me understand?
(Other definitions for grid that I've seen before include "Regular pattern of horizontal and vertical lines" , "Crossword pattern" , "this 15x15 space?" , "a network of squares as in this puzzle" , "Electrical network - American football field - grating" .)