Sherlock Holmes is renowned for his exceptional deductive reasoning and ability to draw astonishing conclusions from seemingly insignificant clues. Throughout the Sherlock Holmes stories, he demonstrates numerous remarkable deductions. Here are a few notable examples:
In "A Study in Scarlet," Holmes deduces that Dr. Watson has been in Afghanistan based on the tan line on his wrist, which indicates that he used to wear a wristwatch but had stopped recently since the watch would leave a paler mark when worn regularly.
In "The Adventure of the Blue Carbuncle," Holmes deduces the owner of a lost hat and the events that led to its abandonment by carefully examining the hat's condition and the man's profession based on the type of hat he wore.
In "The Adventure of the Speckled Band," Holmes determines that a woman was killed by a venomous snake due to the presence of a ventilator leading to her room and a saucer of milk left outside, which the snake drank from.
In "The Adventure of the Dancing Men," Holmes deciphers a series of coded messages sent to a woman by recognizing that the characters represent a substitution cipher based on their frequency.
In "The Adventure of the Norwood Builder," Holmes deduces that a supposed murder victim is still alive based on the lack of a body, the financial motive, and the victim's handwriting in a will.
In "The Adventure of the Greek Interpreter," Holmes deduces that a man is held captive based on his client's knowledge of Greek and the secret message conveyed by the client's brother through a coded phrase.
In "The Adventure of the Engineer's Thumb," Holmes deduces that a man had a dangerous encounter by observing his injured thumb and deducing the events leading up to it.