Jimmy Wells and "Silky" Bob are so much like the tortoise and the hare in Aesop's well-known fable that it almost seems as if O. Henry wanted to write a modernized version of the story with human characters. In the fable the two animals engage in a foot-race. The tortoise moves slowly, of course, but advances steadily. The hare takes off with a burst of speed and leaves his opponent far behind. But then the hare decides to take a break, since the poor tortoise does not seem to have a chance of winning. When the tortoise catches up with him, the hare speeds off again and then takes another break. In the end the tortoise beats the hare to the finish line because he passes him while he is sound asleep. The moral of the fable, which is spelled out at the end in some editions of Aesop's Fables, is "Slow and steady wins the race."
Bob has been like the hare for the past twenty years. He tells the policeman, whom he doesn't recognize in the dark as Jimmy:
"You see, the West is a pretty big proposition, and I kept hustling around over it pretty lively."
Bob is obviously some kind of a crook, probably a confidence trickster. He has to keep "hustling over it pretty lively" for at least two reasons. One is that he cannot stay in any place where he has made enemies by victimizing the local inhabitants. The other reason is that he is in chronic danger of being arrested, either for a local crime or for one he committed elsewhere at an earlier date. These two truths about the life of crime have been dramatized in at least three excellent movies: Bonnie and Clyde, Butch Cassidy and the Sundance Kid, and Paper Moon.
Bob describes Jimmy in the following terms:
"He was a kind of plodder, though, good fellow as he was....A man gets in a groove in New York."
In the end it is Jimmy, the plodder, the tortoise, who wins the race. He has a good steady job. He is probably married and has a home and a family. Bob has a diamond scarf pin and a diamond-studded watch, but he is being hauled off to prison, where he might have to serve multiple sentences for multiple crimes. Whatever money he has managed to accumulate, if any, will probably go to pay a lawyer. Bob has nobody to care about him, which is why he has traveled a thousand miles to see his old friend Jimmy.