Has an AFL game ever ended 99-23?
Exactly once. On May 21, 1904, Fitzroy beat Melbourne 99-23, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 99-23 in league history.
That makes 99-23 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 100-23 has happened never and 99-24 has happened never.