Jestli se budoucí Biff vrací do 2015 hned po tom, co dá mladému Biffovi almanach, mohl by se vrátit do 2015, kde Marty a doktor jsou.
If future Biff goes back to 2015 right after he gives young Biff the almanac, he could get back to the 2015 with Marty and Doc in it.