If a person tells you that something is "the real McCoy,” they are telling you that it is the real thing. It is not a copy or replacement. There is nothing false about “the real McCoy.” And, not only is it the real thing, it is the best version that exists.

As usual, word experts do not agree on how this expression came into common use. A popular belief is that it is connected to Charles “Kid” McCoy, a famous boxer of the past. During the 1800s, he was a one-time world champion. His real name was Norman Selby. Word historians also cannot agree on which Selby story is the origin of “the real McCoy.”

One explanation goes like this: McCoy was having a drink in a bar with a woman friend. As the story goes, a man at the bar insulted McCoy by calling him a liar. He said he was not the famous prize-fighter. So, McCoy knocked him out with one hit. When the man came to his senses he called out, “That was the real McCoy!”

The second version of the Kid McCoy story is much less flattering to the boxer. McCoy was accused of throwing many fights. To throw a fight means to lose on purpose for money. So, sportswriters would ask, “Who is going to show up for the boxing match? The boxer who throws the fight or the real McCoy?”

However, there are other explanations for “the real McCoy.” One story takes us back to the days of Prohibition in the United States. During this time, it was illegal to sell alcohol. That, however, did not stop people from selling it. And many people sold low quality alcohol.

As this story goes, there was one dealer who was honest. His name was Bill -- you guessed it -- McCoy. He refused to sell bad alcohol. Over time, his product became recognized as the best. It was called “the real McCoy.”

The expression made it through the days of Prohibition and soon became a general term. But not so fast.

Yet another possible explanation is from Canada. Canadian inventor Elijah McCoy made a successful machine for keeping train engines running smoothly. He patented his design in 1872. But that did not stop others from copying it.

These copies were all inferior, or not as good. So, railroad engineers would request the patented design by name. They wanted “the real McCoy” system for their trains.

Similar expressions include “the real deal” and the “genuine article.” The adjective honest-to-goodness means the same thing. Now, let’s hear these expression used in a short dialogue.

"Wow, is your computer the new Banana Book Pro 5000?"
"You bet it is. It is the real McCoy. And it should be. I paid enough for it!"
"I’m afraid to ask … but how much did it cost?"

"More than $2,000."
"That is a lot of money. But like you said it’s the genuine article."
"Yep, you get what you pay for. There are many copies out there. So, you have to be careful."

"Absolutely. The only way to really buy the Banana Book Pro is at the Banana store. That is where you bought it, isn’t it?"
"No. I bought it from a guy selling them out of his car. But he promised that it was an honest-to-goodness Banana Book Pro. He showed me the paperwork and everything."

"Well, then. I’m sure it’s the real deal. Do you mind if I see the … uh oh, sorry, the logo just fell off. It’s a good thing you have the paperwork."

Is the Banana Book Pro the real McCoy? We may never know. And we may never know which story, if any of them, truly explains “the real McCoy.”