I don't know the mathematical formula either, but I do know that to gain trust rank you have to receive zaps, preferably high ones, from stackers with high trust rank. zapping hard top posts and comments too.

Yes, I know. But whenever I see such a huge difference I see 'trust rank' as something that might be a very powerful thing for SN in future. 

I'm still to understand how one gains this power on SN.

Coinsreporter

Yes, trust rank has more influence. It's a kind of ranking point multiplier. It's the same thing for downzaping.