Have you looked at this?
https://www.ifpapinball.com/tgpguide/
If yes, play around with this:
http://tgp.slapsave.com/
Keep in mind that the IFPA has consistently tweaked their formula so it's hard to have a relatively high TGP in a relatively short event. It's still possible and reasonable to try to efficiently raise your TGP, of course.