Aaron Sorkin wrote or co-wrote 85 of The West Wing’s first 88 episodes.
Those 88 episodes comprise the show’s first four seasons, the period in which Sorkin served as creator and principal writer. His unusually dominant role helped give the series its distinctive rhythm: rapid exchanges, elaborate political arguments, and long tracking shots through the White House corridors.
Sorkin did not work entirely alone. The writing staff developed research, story ideas, and drafts, and several other writers received credits. Nevertheless, the final writing responsibility for nearly all episodes in the first four seasons remained associated with Sorkin.
He left the series after season four, along with executive producer Thomas Schlamme. The show continued for three more seasons under new creative leadership, but viewers and critics often distinguish the Sorkin era from the later episodes. The number 85 is therefore not a claim that he personally wrote every line without assistance; it counts episodes credited to him as writer or co-writer.