the 'even good / odd bad' rule
Imo this never held any water as I considered III to be one of the best films (after II imho) but me aside maybe its not that well regarded and the IMDB/RT scores are probably more in league with the lesser entries
The next anomaly would be Nemesis where the rule completely falls part as everyone considers it one of the worst. and again it falls apart with XI as everyone loved it and it totally rejuvenated Trek. then with XII - STID audiences seemed to like it but hard core trekkies seems to loath as it dared to remake II (so I guess you'd call that a win for the even = good debate). but XIII Beyond was a stinker to everyone but the hard core fans maybe and even they have to admit it wasn't that great (so back to odd = bad)
So really the anomalies in the even good/odd bad theory are III (as its good), X (as its bad), XI (as its good)... and sort of XII (as trekkies consider it bad but general audiences are ok with it)