A LOT IN COMMON
The correlation between certain types of puzzles and, say, forms of poetry is fairly straightforward. Here we have the constraints imposed by Sudoku puzzles and Villanelle poems.
As Peter Turchi explains:
It must be a nine-by-nine inch grid. The grid must be further divided into nine three-by-three squares. Each square in the grid must be filled with the numbers 1-9. No number may be repeated in any horizontal line.
No number may be repeated in any vertical line. No number may be repeated in any three-by-three square. The puzzle composer omits certain numbers, and those omissions
allow for one unique solution.
It must have nineteen lines. The nineteen lines must be further divided into six stanzas. The first five stanzas must be tercets. The final stanza must be a quatrain. The poem must have two refrains. The poem must have two repeating rhymes. The repeating rhymes must be in the first and final lines of the first tercet. The rhymes must repeat alternately in tercets two through five. The quatrain must include both repeated lines and both rhymes.