Well Clifford... I'll tell ya.
I recently went from split-finger to three-under myself. I have a buddy that shoots a lot of 3-D tourneys and we were goofing around one day, stump shooting. "Closest one picks the next shot" sort of thing and he was kicking my butt!
Now, I know he doesn't practice more than I do, heck he's nearly blind in one eye and can't see to good out of the other! That's why I enjoy shooting with him, it makes me feel better about myself. I just couldn't figure out why he was shooting so well. It wasn't that I was shooting bad, I was hitting at my "so terribly close, but no cigar" best.
Then I noticed he was shooting three-under. I asked about it and he admitted to switching a few weeks ago. He said that it had increased his 3-D scores by a huge margin, especially for those targets at further distances. He said that I should try it; it couldn’t make me shoot any worse. I didn't think it could make THAT much difference, but, being a friend I didn't want to Poo Poo what might just be his only mental crutch (in spite of the sharp verbal jab). I humored him and gave it a try. BINGO! We were back to the normal 50/50, he gets one, and I get one manner I was accustomed to.
Upshot of all this is, I shoot more accurately with three-under than I do split finger, especially at greater distances. Don't know why. Maybe because it’s closer to my eye; maybe I get a cleaner release that way. Maybe it cuts down on the Sub-Space Interference between my ears, no clue.
All I know is that it works for me, maybe not for others. Some folks like green Jell-O, some don’t. Although I consider myself a fairly inquisitive kinda guy, I'm leaving it alone. I don't want to jinx anything, it works, 'nuff said.
Sounds like it works for you too. If you find out why it works, FOR GOD’S SAKE DON’T TELL ME!
Good luck with your shooting, welcome to the club.
OkKeith