Last summer we converted my "big board" from vBulletin to IPB. We probably didn't go about it the right way because we changed the directory which changed all of the url's - ex. from /boards/ directory to /forum/ directory. After a couple months we decided to go from IPB back to vBulletin, changed the directory name again, and traffic dropped again. Now SE traffic is steadily climbing but it's still only 1/3 of what it originally was.
I would like to eventually convert that vBulletin forum to XF but I don't want to take another hit on the search engines. I guess I'm wanting someone to explain the conversion / url redirection process like they were explaining it to a child. Is it possible to convert without taking a huge hit? There must be, I see big forums do it all the time.