I use a deep hook on my string. I shoot split fingers. My index finger goes aginst my jaw tooth, the next finger( middle)goes into the corner of my mouth, my thumb knuckle rest tight behind my jaw bone. This gives me a solid ancher that is consistant each and every shot. You need to experiment and find what is comfortable for you. Just make sure you use a good solid anchoring system against your face.( hand to bone) something that won't move from shot to shot. I don't think it matters weather you shoot split or 3 under just as long as it is comfortable and you find a solid nonmovable anchoring spot, that you can repeat for each and every shot.