Ian Livengood, a puzzle editor for The New York Times, touched on this in last Friday’s Easy Mode newsletter: Some crossword entries are inherently difficult to write friendly clues for. Similarly, the relative ease of an early-week puzzle means that constructors are further constrained by what types of entries can go in the grid.

The Sunday scaries recently took on new meaning for avid New York Times crossword solvers. For the first time in the famed puzzle's 84-year history, a printing mistake rendered it impossible to solve. The puzzle—created by Michael Lieberman and titled ...