Searched a small jar of coins this afternoon and found these 2 coins. Lincoln cent with reverse die crack: then this nickle - to me looks like die deterioration doubling, but I've never seen the doubling from the worn die spread out so much from the letters/numbers before:
Yup, the Jeff is definitely DDD. I have a couple like that myself. When I first found one in 1999, I thought I had discovered the greatest doubled die ever. It was only after researching a bit that my hopes were shattered. A couple years later, I wrote the Wikipedia article on the subject, and shared pictures of my coin on it: https://en.wikipedia.org/wiki/Die-deterioration_doubling
Two completely different causes, with two completely different appearances. Machine damage, or strike damage, occurs right after the striking of the coin. As the dies begin to pull apart, they may "bounce" or "jiggle." This slight shifting of the die will "drag" the devices, and produce a torsional effect. The resulting appearance will be flat and shelflike, often with a rather shiny appearance. Die Deterioration Doubling occurs late in a die's life, after it has struck many coins. The friction of the coin metal rubbing on the surface of the die will wear away the fine details of the die, and may cause the devices to have a bloated or distorted appearance. The appearance is irregular, such as shown in the OP. It isn't flat and shelf-like, so some people confuse it for hub doubling. However, it isn't the rounded, notched, secondary image of true hub doubling - it is instead a shadowy outline of the devices.
No. Very much no. They have the same value (that is, zero premium), but they have very different causes and very different appearances.
Maybe one being more extreme than the other? I did not read your article but I will. Sorry if I am in err here. Edit-Great article and thanks for posting the link. I am much more informed as a result of reading this and I thank you.