What super powers would you want to have if you could only use them while playing baseball? I think a lot of people would say Superman's powers because then you could crush the ball and move really fast. Maybe use X-Ray vision to see if the pitcher's wearing a cup.
Me? I'd want the Invisible Girl's powers from the Fantastic Four. I wouldn't tell anybody that I had the powers though. It would be tons more fun to pull off the old Hidden Ball Trick by turning invisible. And if a throw's coming into home and I'm looking to take out the catcher, I might project an invisible barrier just before the ball reaches the infield to by myself a little more time.
INVISIBLE HIGH FIVE! GO PADRES!