These statistics have been arrived at based on two fundamental assumptions: (a) adpositions constitute a large fraction of function words; and (b) the strict ordering between the adposition and the noun phrase leads to differential co-occurrence characteristics on the left and right sides of the adposition.
if the function words of a language are automatically detected and the co-occurrence statistics on the left and right of those words are appropriately analyzed, then it should be possible to tell the prepositional languages apart from the postpositional ones.