Hand positioning -- curling the pinky under??

[Monte]

I've seen a couple of pros do this. Instead of laying their pinky finger on the ball, like you do with your index finger, I've seen a few of them curl it under. Does that actually do anything, or is it more psychological?

[Amyers]

It allows you to generate additional revs but I believe it can add to wrist problems.

[got_a_300]

I used to do it back years ago when I was younger and it
helped me to achieve somewhere around a 600+ rev rate
but it also caused me a great deal of pain in my hand/wrist
along with creating a large callus on top of my pinkie finger
which has since disappeared.

[bowl1820]

I've seen a couple of pros do this. Instead of laying their pinky finger on the ball, like you do with your index finger, I've seen a few of them curl it under. Does that actually do anything, or is it more psychological?

The pinky tuck is one of those thing's that it either works for you or it doesn't. (IMO I think if someone really wants to do it all the time, they should have their span remeasured while doing it and have the grip adjusted.)

Bill Spigner said this about it: "Tucking your pinky is a mostly outdated method of increasing revs. It’s more important these days to have the fingers behind the ball, which lets swing speed generate revs."

You can read his article here (it's old):
http://www.billspigner.com/pdf/0604_Bill_BD.pdf