Well, grapplers it is real and it's origins are from Jujutsu (also known as Jiu Jitsu and Judo later on.) Yes, the chop existed before the Japanese started using it, but today we are talking strictly about jiujitsu and you.
Some of you are probably fidgeting in your recliners, readying your fat fingers to type in all caps and respond to this post saying something like "My Sensei told me it's from ...." or "Well, a friend of a friend trains with Eddie Bravo and he says he created it" or maybe my favorite "The Gracie family has created jiujitsu and more than 60% of it is new and unique to them." Sorry, grapplers. But, there's about as much truth in these kinds of claims as the assertion that humans roamed the earth with dinosaurs (yes, even though the "Flintstones" seems so real).
Traditional Japanese jujutsu (jiujitsu) is a complete art that has combative aspects that cover standing techniques, throws, ground grappling, weapons and yes strikes. Edge of hand blows were used extensively in jiujitsu, not only to deliver debilitating and possibly lethal strikes, but they were also used to weaken your opponent and open them up for locks, chokes and throws.
Why it's so effective? Well the thought behind it is that closed hand punches are often unreliable and often lead to broken hands and wrists and a closed fist also has a much larger surface area. The edge of hand strike has much less surface area and concentrates the blow to a precise area. It can also target vital spots on the body such as the neck much more efficiently than a punch.
What what does this mean for you? Well I suggest you play with the edge of hand technique and maybe pick up a book to read more about prewar Judo and Jujutsu. It also might be fun to chop the crap out of that whitebelt that won't let go of his grips.