Final Answer:
John Clay and Ross Duncan start The Red-Headed League in Sir Arthur Conan Doyle's "The Adventures of Sherlock Holmes" to divert the attention of Jabez Wilson, a red-headed pawnbroker, by creating a fictional league and thus enabling them to execute a bank heist without interference.
Step-by-step explanation:
In the story, John Clay is a skilled criminal, and Ross Duncan is his accomplice. They devise a clever plan to distract Jabez Wilson, who possesses a unique characteristic—his distinctive red hair. To keep Wilson occupied and away from his pawnbroking business, Clay and Duncan create a fake organization called The Red-Headed League, claiming that Wilson has been chosen as a member. The league's supposed activities involve copying the Encyclopedia Britannica, and Wilson is paid for his participation.
The true motive behind this ruse is to ensure Wilson's absence during specific hours, allowing Clay and Duncan to tunnel from the pawnshop into the nearby bank for a planned robbery. Sherlock Holmes unravels the scheme, exposing the criminals and thwarting their intentions.
Therefore, the answer is that John Clay and Ross Duncan initiate The Red-Headed League to carry out a bank heist by diverting Jabez Wilson's attention.