That group of Actors from the 80s that seemed to be in every movie made during the period.
The Original Brat Pack is culled from three movies:
The Breakfast Club
St Elmo's Fire
Other actors have to have acted with the main Brat Pack at least once.
Four tiers of actors
The central Brat Pack, who were in at least 3 films of the period
The outer Brat Pack, who were in at least one of the original Brat Pack movies above
The Secondary Brat Pack, who were in at least 3 Brat Pack films
and the outer ring, who acted in at least 1 Brat Pack film