Pens, pencils and a facility with numbers. Also helpful: earplugs, plushies, a water bottle, calming herbal oil and the occasional “wild bifurcation” (a.k.a. a wild guess). Competitors at the World ...

The game’s most devoted solvers have unlocked creativity and complexity in the classic logic game. By Elie Levine and Sam Corbin Sudoku is like any other logic puzzle, in that it relies on deductive ...