The pre-qualifying "reshuffle" took place at the mid-season point (after round eight) and was reorganised to take into account the top 26 cars/13 teams (not necessarily the same thing with single-car entries still in the mix) of the previous two half-seasons - in this case the final eight races of 1989 and the first eight of 1990. By the time you get to the last couple of races of 1990, though, enough cars had dropped out (Onyx/Monteverdi, EuroBrun and Life) that there was no need for it. Until the start of '91...