What Were the Other Six?

Holmes and Watson with their client in "The Copper Beaches"

"What can be the matter, then? Can you suggest no explanation?""I have devised seven separate explanations, each of which would cover the facts so far as we know them."

-- "The Adventure of the Copper Beaches"

Has anybody figured out what were the other six?

Holmes says something like this on a couple of other occasions, as I recall - again tossing out the mystical number of seven possible solutions or courses of action. The good Watson, of course, never challenges him.

Enoch Hale, hero of what eventually will be a trilogy of Holmes-related historical mystery novels by Kieran McMullan and me, isn't so passive. In the The Poisoned Penman, in a chapter called, "The Seven Solutions of Sherlock Holmes," Hale challenges Holmes's claim that he could think of seven separate solutions.

“Wait a minute.” Hale looked at Holmes square in the face. “Whenever you told Watson that kind of thing—‘seven separate solutions’—he just swallowed it without question. I’m not so easy. What are all these possible solutions? And I want to hear seven, not six.”

With a sigh, Holmes lists all seven. But, of course, there will be no spoilers on this blog. I hope you read the book and see what they are.