Has an AFL game ever ended 104-51?
Yes. AFL has seen a final score of 104-51 2 times. It first happened on May 31, 1930, when Essendon beat Sydney, and most recently on August 6, 2006, when Fremantle beat Hawthorn.
That makes 104-51 the 2421st most common final score out of 6,607 that have ever occurred in AFL. One point away, 105-51 has happened 3 times and 104-52 has happened 3 times. At one point the score disappeared for 76 years, between 1930 and 2006.