I've generally liked shooting three under but I noticed that I was having some string torque issues pop up every now and then. So I decided to try split again, but I really think of it as two under and a half. My top finger is hardly on the string at all but I use it to touch my eye tooth. Darn it if I don't feel more comfortable and the shooting shows. Anchor is double solid and sight picture feels sharper as well.
I switched back to split also,for the same reason and also because it gives me more confidence on the hook-up.If that makes any sense.I'm shooting just as well as I was 3 under.
I have always shot split finger, but a few weeks ago I tried 3 under(cause I see so many doing it). I kept my anchor the same, middle finger to corner of the mouth, and with the release the string bout ripped the side of my nose off. Needless to say,,,back to split finger! "If it ain't broke, don't try to fix it."
I have a bit of trouble with string torque with 3 under. FWIW, for awhile I was pulling with 4 fingers to get my elbow down, then remove the little finger when I was anchored. That reduced the torque. But then I finally realized that a deep curl with the fingers seemed to do the same thing. So, for now, I'm sticking with 3 fingers under.
I have noticed I can snap off a quick short range shot easier, and accurately with 3 under, But I prefer split.
3 under might be good if I surprise a bedded hog, or rabbit, but I'd need to practice more to be proficient.