Check out these pictures http://www.chrisoleary.com/projects/Baseball/Pitching/PitcherProfiles/DanHaren.html
Look how he grips the ball
-second picture, is that a 4seam fastball grip? His thumb is under his index finger, not between index and middle finger. I gues he uses his pinky and ring finger to hold the ball as well?!
-third picture. Same thing with the grip, but its a 2seam fastball? If you zoom in the picture, you will see that his index finger is not on the seam?
So I gues when you grip a 4seam (or 2 seam) fastball your thumb dosen’t need to be under and between the index and middle finger(which I find to do with small hands of mine)?
Hard to know all these things since there are no pitching coaches in this part of the world…