The phrase “to know the ropes” means to be familiar with all the details.
There have been differences of opinion about the origin of this saying, for it so happens that the earliest records make it appear that the phrase was first used by the gentry of the racetracks, and, because of that, some hold that by “ropes” the allusion is to the reins of a horse’s harness; that one “knows the ropes” who best knows the handling of the reins.
But, as with many other phrases, this one, we think, undoubtedly originated among sailors.
An experienced sailor, in the days of sailing vessels, was one who was familiar with the bewildering array of ropes leading to all parts of the many sheets of canvas under which the vessel sailed.
Such a man literally “knew the ropes.”