Sudoku vs Crossword: What the Research Shows

Sudoku and crossword are the two most-played puzzles in the English-speaking world, and they get compared all the time. Newspapers run both side by side. Older readers often do one, younger readers often do the other. The polite question is which one is better for you.

The honest answer is that they exercise different things, and neither one is medicine. Here is what the research actually shows.

The PROTECT study, again

The largest observational study of puzzle players over fifty, the PROTECT cohort at the University of Exeter, did not split crossword players from sudoku players. Both groups appeared in the "regular puzzling" category, and that category showed better scores on memory and reasoning tests than the non-puzzling category. The study cannot tell you which puzzle deserves the credit.

Earlier work by the same group has hinted that crossword players show slightly stronger verbal benefits, and sudoku players show slightly stronger pattern-recognition benefits. The differences are small and the study designs vary, but the direction makes sense given what the puzzles actually demand.

What each puzzle exercises

The verbal advantage of crosswords

Crossword clues require retrieving facts, words, and trivia from long-term memory. That kind of retrieval is closer to everyday conversation than sudoku scanning is. It is also more vocabulary-dependent, which is one of the reasons crosswords feel harder when you do them in a second language.

The downside, depending on your goals, is that crossword skill is partly knowledge dependent. A crossword that asks for the name of a 1970s Italian footballer is unsolvable to most under- thirties, no matter how much working memory they have.

The visual advantage of sudoku

Sudoku does not require cultural knowledge of any kind. It is purely a structural puzzle, and the rules are universally teachable in two sentences. A sudoku is the same puzzle for an eight-year-old in Toronto and a seventy-five-year-old in Tokyo, and both can solve it if they can read digits.

That universality is the reason sudoku spread faster than any crossword variant in the 2000s. The puzzle does not assume any background beyond literacy in any one writing system that uses recognisable digits.

The honest comparison

For most adults, the choice between sudoku and crossword should be based on which one you will actually do every day. The consistency of daily engagement matters more than the marginal cognitive advantage of one puzzle over the other.

If you already do one of them, keep doing it. If you do neither, try both for a week. Whichever one you reach for unprompted on day eight is the one that fits you.

Doing both

Many lifelong puzzle players alternate. A crossword with the morning coffee and a sudoku in the evening, or vice versa. The two exercise different brain regions and do not crowd each other out. A daily one of each takes about thirty minutes combined, which is no longer than a single bad commute.

For a longer look at the sudoku side of the research, see sudoku and the brain. Or try a medium puzzle now and see how it feels next to your morning crossword.