I always felt that Holmesian reasoning was characterized by reliance on obscure technical knowledge, like the different kinds of ash produced by various cigars, or else by noticing seemingly irrelevant details.
For example, a screenshot of my desktop would reveal (among other things) a button labeled 'us' in the panel. From this you might infer that I use a nonstandard keyboard layout. Browsing through my comment history would probably give you enough text to guess that I'm a native English speaker, so from this a reasonable guess (and the correct one) would be that I use Dvorak.
This, on the other hand, is just silly. Holmesian reasoning should, above all else, sound plausible to someone who doesn't understand how evidence works.
In Sherlock Holmes fiction, we see that Holmes is capable of making correct inferences using insufficient information and long, tenuous chains of reasoning. I'm curious what would happen if we tried to apply this in real life. Here's a riddle containing insufficient information to come to the right answer with any certainty; will our Holmesian reasoning attempts be anything close to the "correct" answer, or will it be totally off?
Use your meta-riddle awareness: this isn't just a random event, but the sort of event that I would make into a riddle.
Here's the answer I had in mind, rot13'd.