I've heard of that 2nd knuckle release, but I'm like you im not sure how it works. TJ Conrad said in his book to shoot from the finger tips, but I get a cleaner release with a deep hook in the first finger joints. Somewhere I read that the deep hook relaxes your hand and fingers for a better release. If I shoot of the fingertips with a tab that I made. I get all kinds of erratic arrow flight if I hook it deep in the first joint they fly perfect, I dunno, I stay confused about it mostly and just shoot whatever makes my arrows fly right.