Statistics on Difficulty of Sudokus

There is now reliable, objective way to measure the difficulty of a given Sudoku. Therefore these statistics compiled from how fast or slow humans solved the Sudokus on the one hand, and how many people solved a given Sudoku on the other hand.

Average Solving Time

All times are given in Seconds.

Overall Statistics

Average	652
Std. Deviate	112
Minimum	412
Maximum	2601

Easiest and Hardest Sudokus

The Sudokus that were solved fastest/slowest on average.

	Easiest		Hardest
No	Mean Time [s]	Sudoku	Mean Time [s]	Sudoku
1	413	2010-08-04	2602	2011-01-22
2	424	2009-08-04	1845	2006-10-14
3	425	2011-06-12	1316	2012-02-04
4	430	2006-10-04	1276	2011-06-30
5	431	2007-04-03	1270	2010-12-25
6	431	2011-07-31	1245	2010-04-21
7	435	2007-01-18	1228	2009-11-18
8	436	2009-11-15	987	2008-10-29
9	436	2011-03-25	984	2009-12-07
10	442	2009-12-03	974	2010-10-07
11	442	2009-12-09	966	2009-08-03
12	444	2010-01-13	960	2007-09-07
13	444	2010-10-20	956	2010-10-06
14	447	2007-06-16	944	2009-02-17
15	450	2006-11-06	942	2010-02-06

Number of People Who Solve a Sudoku

Most Difficult Sudokus

These Sudokus have been solved lest often: