Current wisdom is to grab the string with the deep hook into the joints, and it is a stronger hold. I' ve tried it, but with the deep hook I wind up with a cupped hand. I still prefer to shoot off the pads of my fingertips. I get the string on the back of the pad on my middle finger, right in front of the joint, with the index finger and middle finger holding midway up the pads. The index finger and ring finger aren' t supposed to be holding as much weight anyway.
I' ve shot draw weights up to 120 pounds using that grip (when I was younger and had more testosterone than brains).