Has an AFL game ever ended 81-81?
Exactly once. On May 8, 1937, Sydney and Richmond drew 81-81, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 81-81 in league history.
That makes 81-81 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 82-81 has happened 5 times and 81-82 has happened never.