why does holmes find the jabez wilsons story intresting

Sherlock Holmes likes a challenge. His razor-sharp intellect loves nothing more than to get to grips with cases that are out of the ordinary or have an unusual combination of facts. Jabez Wilson's story definitely fits into that category. At the beginning of "The Red-Headed League," Holmes reminds Dr. Watson of what he told him recently, that real life has more strange effects and extraordinary combinations than the imagination could ever possibly conceive. Watson was doubtful of this. But Holmes is confident that, when Watson hears the full details of Jabez Wilson's case, he'll come round to his way of thinking.
What is particularly fascinating for Holmes about Wilson's story at this stage is that he doesn't even know if an actual crime has been committed. This only adds to the mystery, and makes Holmes even more intrigued. Not only will Holmes have to solve a crime—if indeed a crime has been committed—he'll first have to establish that one has taken place. The case of Jabez Wilson promises to test Holmes's famed powers of deduction to the absolute limit. He can't wait to get started.