The Adventures of Sherlock Holmes
Arthur Conan Doyle's twelve stories from the Strand.
216 cryptograms drawn from it, every one by Arthur Conan Doyle.
How hard they are
59 easy, 87 medium and 70 hard, graded by the model described in our guide to solving cryptograms.
They average 70.7 letters over 19.2 distinct ones, with 4.3 letters appearing exactly once.