History Backs Melbourne in Grand Final Rematch
The 2022 Toyota AFL Premiership season kicks off tonight with the Melbourne Demons hosting the Western Bulldogs at the MCG in a Grand Final rematch.
If you ask me who I think will win, I’m backing Melbourne.
Now, I know picking the reigning premiers to with a Grand Final rematch isn’t an outrageous opinion.
In most cases, it’s a matter of common sense. A team that is good one year can normally be expected to be good the following year, provided there isn’t a mass exodus of playing and coaching staff, or they get smashed by injuries.
But if you’ve read any of my previous AFL-related posts, you know that I look for answers in the stats.
And the stats back Melbourne.
Don’t get me wrong, stats can be misleading. They don’t account for changes in personnel, injuries, or performances in the pre-season—although ignoring that last one is challenging after the thrill of seeing Carlton knock Melbourne off in the AAMI Community Series.
But back to the stats. Throughout V/AFL history there have been 273 Grand Final rematches, or games where the two Grand Final teams play again the following year.
There has been at least one Grand Final rematch every year. Interestingly, most years (74 of 122, or 61%) have had two Grand Final rematches. And if you can believe it, there have been 13 years with four Grand Final rematches the following season; most recently in 2003 when the Brisbane Lions played Collingwood in round 4, round 19, the qualifying final, and the Grand Final.
The reigning premier has won 146 of the 273 Grand Final rematches, which comes in at 53%. The stats don’t really change if you only look at the first Grand Final rematch the following season: 65 of 122 matches fall the way of the premier (also 53%).
Things look more positive for Melbourne if you look at Grand Final rematches that have occurred in round 1. Two thirds of these rematches have been won by the premier (12 of 18 for anyone who is interested). However, the only time Melbourne played a Grand Final rematch in round 1 (versus Essendon, in 2001) they lost by six points.
Interestingly, the reigning premier seems to perform better in Grand Final rematches the earlier they occur in the season. Let’s look at the figure below, where I’ve plotted the percentage of times the reigning premier wins the first Grand Final rematch by the round the game was played in.
From the graph above we can see a trend for the win percentage to decrease the longer into the season. I have no idea what happens in round 9 Grand Final rematches, where the reigning premier has won every time. If anyone has any ideas, I’d love to hear them.
The table below details a range of different scenarios with corresponding win percentages for the two Grand Final teams.
Admittedly, it’s not all bad for the Western Bulldogs. They have a better win percentage in all the scenarios presented above compared to Melbourne. However, it’s important to remember these figures are somewhat inflated due to the smaller number of Grand Finals the Western Bulldogs have appeared in.
Which is a perfect segue into this great meme about effective and reliable sampling methods:
Credit to u/Bmchris44, who posted this to reddit, and the original creators of the post from tumblr
Overall, the stats back Melbourne. Hopefully the Grand Final rematch is every bit as entertaining as the Grand Final itself.
As always, I apologise to anyone who has already looked at these stats.