What is the origin of the idiom "by a long shot" and when to use it?

The idiom "by a long shot" is believed to have originated in American English in the mid-19th century. It likely comes from the world of shooting or marksmanship, where a "shot" refers to an attempt or a bullet fired from a firearm. A "long shot" in this context would be a shot taken from a considerable distance, making it less likely to hit the target accurately. This phrase is often used when one thing surpasses or falls short of another by a noticeable degree.