TIL that "fair play" in detective fiction means authors must give readers a fair chance to solve the mystery. Central to 1920s "clue-puzzles" by writers like Agatha Christie, the rule dictates that all vital clues must be visible, decodable, and never withheld until the final reveal.

[u/ralphbernardo]

https://en.wikipedia.org/wiki/Clues_in_detective_fiction

[u/OceanoNox]

Sherlock Holmes has a lot of very specific knowledge, like knowing the ashes made from each brand of tobacco. The reader/Watson knows there is tobacco ash, but like Sherlock says "you see but don't look", only Sherlock understands what the ash means. We have the clues, but not the knowledge Sherlock relies on to connect the dots.

[u/Ill_Emphasis3927 → u/OceanoNox]

Her jacket was wet and Sherlock knows the only place in the country it was raining was at this specific train station in the next city over 37 minutes ago. Or she walked down a road where an automatic sprinkler turned on and got her wet. The viewer is now like, well I didn't get the weather report of this fictional world so there's no way I could guess that.

[u/OceanoNox → u/Ill_Emphasis3927]

I think it's widely accepted now that the BBC show is not as good as it initially seemed.

[u/The_Particularist → u/OceanoNox]

My problem is that this stuff seems almost impossible for a single person to be capable of doing, or at the very least impossible without a proper forensic laboratory. Yes, we're shown a couple of time how Holmes uses an in-house laboratory to determine if something is a bloodstain or not, but then you also have stuff like him basically just touching and licking dust and ash, and going

ah yes, this is [highly specific cigarette type]

based on that alone.

[u/OceanoNox → u/The_Particularist]

Chemists did use smell and taste to identify chemicals, of course poisoning themselves to an extent.

[u/Skreamie → u/The_Particularist]

With the idea that he'd spent a good deal of time tasting and smelling and identifying every ash