Mostly the hitter.Are you trying to highlight the pitcher or the hitter?
For hitter, dual cameras are nice, if you can swing it. One camera to capture the field from behind. The second camera would be placed on the opposite side of the hitter, perpendicular to the ball path.
We edit all of our video in Adobe Premier Pro. Premiere Elements will serve most people, but you lose the ability to batch process renderings (the very long, system intensive process of producing the final file). The PnP process can be as complex as using "Keying" which allows for the fuzzy round edges shown in our sample above. You create a black BMP file representing the shape you want the video. You use the keying effect and apply the second video file. Or you could just as easily go low tech and drop the second video on top of the main. Then use the sizing, cropping, and moving effects to place the video wherever you want. It isn't as pretty. But it is much faster to develop and renders much faster as well. This is an example of that:What do you use to get the picture in picture? Is there an app?
deadHere is a website with the examples I have used for all my video, let me know if you have questions, happy to help.
www.fastpitchsportsvideos.com