knuckles

As per title, doing knuckle conditioning on flat surface bit by bit (tbh I just like the feeling), on my right hand bottom three connect perfectly, but on my left it's impossible, ring finger knuckle just sticks out too much or something, I can't touch all three even on purpose, unless the ring...

In the book "Championship Fighting: Explosive punching and Aggressive Defense" Jack Dempsey reccomends to punch with the last three knuckles of the hand (the pinky, the second and the middle), and to aim with the second. Some people recommend punching with the index and the middle. Some...