Four leaf clovers happen on plants that normally have three leaves. Mutations and variations happen. Here's a link to a website on 4-leaf clovers and shamrocks. It has the "estimate" of finding a 4-leaf clover is 10,000 to 1. I don't know how likely ginseng is to have extra leaves but I'd probably liken the 6-leaf to the 4-leaf clover.

FataMorgana

Here is a link that might be useful: Shamrocks & 4-Leaf Clovers

yeah i feel so lucky to have found a plant like this. i mean as rare as ginseng is anyway. if the odds of this plant were about the same odds as a four leaf clover. then that would make this a really rare plant. makes me feel lucky. I carefully dug the plant up and replanted it in a place closer to my house so i could keep up with its growth from year to year. i also wanted it around for good luck lol.