But I do like some video games, so it’s not the mindlessness or lack of productive engagements. But then given your comment, maybe it’s exactly that “mental abstraction” that’s attractive about Sudoku.

Thanks for the explanation of complexity — I was expecting something asymptotic (something about complexity in general as problem size grows in terms of number of cells).

]]>Savage, L. J. (1976). “On rereading R A Fisher.” The Annals of Statistics 4(3): 441-500.

that it was shock to him to realise what a very good mathematician RAF really was.

]]>As for the complexity, Watanabe considers depth (minimal number of forward steps necessary to reach a solution or a deadend) and width (number of parallel scenarios one had to pick from). I cannot tell what went wrong with his derivation, producing a puzzle I was able to

solve in half-an-hour…

See Bennett, J. H. (1990). Statistical Inference and Analysis Selected Correspondence of R.A. Fisher. Oxford, Oxford University Press. (pp273-276).

]]>See R. A. Fisher and F. Yates (1934). The 6 × 6 Latin squares. Mathematical Proceedings of the Cambridge Philosophical Society, 30, pp 492-507. doi:10.1017/S0305004100012731.

A picture of a stained glass window in the form of a 7×7 Latin square honouring Fisher can be found here: http://www.senns.demon.co.uk/FisherWeb.html and you will also find a link to the Fisher archive at Adelaide where you can obtain the paper.

Stephen

http://www.colloquial.com/games/sudoku/java_sudoku.html

How do people study the complexity of Sudoku? Is there a class of Sudoku-like puzzles that grow in size? Do you just grow from 3 x 3 to 4 x 4 puzzles with numbers 1:16? Does that then require an overall 4 x 4 grid?

]]>” (Added on Mar. 11, the created puzzle can be solved easily by hand. Our definition of the difficulty is inappropriate.) “ ]]>