Has an AFL game ever ended 33-21?
Exactly once. On July 31, 1897, Geelong beat Fitzroy 33-21, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 33-21 in league history.
That makes 33-21 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 34-21 has happened never and 33-22 has happened never.