More and more, probably most really fine archers use the deep hook. It seems counter-intuitive at first. But once you get it down it enables you to relax most of your hand and arm muscles and get a cleaner release.
Note that some anchor in the crease, but many including me anchor still deeper in the pad of the second phalange of the middle finger, beyond the crease. The first and third fingers then fall where they may.
I let the string roll down that pad and get a small callous just above the crease of the second finger. I find it comfortable, relaxed, and pain free.
I believe that most Olympic coaches, who have studied all aspects of archery form, generally teach this method.
One clear result is that it enables you to hold the back of the hand flat, not curled as with the finger tip hold. And I think this is a stronger, more relaxed position. - lbg