Has an AFL game ever ended 129-121?
Exactly once. On April 18, 1998, St Kilda beat Hawthorn 129-121, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 129-121 in league history.
That makes 129-121 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 130-121 has happened never and 129-122 has happened 2 times.