It's elementary. E.g. if he's in seat 3 at a 6-max table, the donor is in seat 6, seat 1 on his right becomes vacant and all the other seats are occupied, the predator re-opens the table, sees two vacant seats that are separated by only one occupied, and lands into the right of these two seats.
To visualise the process:
Before closing
After reopening
In case of ambiguity, he can also memorise where the dealer button is at the moment of closing the table.
(You can select a seat if you use the small black 'Open the table' button at the bottom right of the lobby instead of double-clicking the table name on the list. I have no idea why this is still allowed. The player should be automatically taken to the seat where s/he was when last sitting at the table within a couple of hours, unless that seat has been taken by someone else, of course.)
Last edited by coon74; 05-30-2016 at 11:44 AM.