I shot them underhanded with a couple of friends just a week ago. It is incredible how much easier it is and I am not a knockdown shooter. My friends each made 4 in a row, on their first try! Naturally, we came to some simple conclusions;
- you have a better balance, as you are aligned, squared up perfectly toward the board
- you use less force enabling a softer touch, favoring missed shots going back in.
- when I was a kid, my father taught me a general idea to use both hands to get better results. It applies here as well.
- Even if you overshot it, the attempt has a fair chance to bounce in from the backboard.
- both hands enable a better backspin
After those tries, we really couldn't figure it out, why some of the worse lumberjacks (DJ, Drummond, Robertson) don't use this overall better technique. If just one guy tried it he wouldn't be worse at it, he would show the willingness to improve his critical flaw to the fanbase, and it is so retro that it would be ultra cool to many.
I think that a guy like DJ could even get some severely uncontested 3pt attempts when aligned in perfect 90 degrees (only possible then) toward the basket. I bet that he would bank in some.
Historically the whole underhanded shot narrative reminds me of concrete.
We forgot how to use it from 400 BC to 1600 AD. http://www.auburn.edu/academic/architecture/bsc/classes/bsc314/timeline/timeline.htmat
At one point we abandoned the better technique, basketball or construction wise.
I haven't read your link yet since I wanted to have a clear empiric perspective on the shot. Now I will do it