Elo Predicts

Congratulations to the West Coast Eagles on their thrilling victory over Collingwood to close out the 2018 Season! Starting this Elo rating project has provided me with a new insight into team performance, and I hope the same for the readers of this blog. The rating system predicted 4 out of 9 finals, including correctly predicting the winner of the Grand Final. This is a lot lower than I would like, so there is room for improvement in the offseason. Like the BBL ratings I found that home ground advantage doesn't necessarily apply in the AFL, especially as West Coast were technically the home team (as they finished higher up the ladder) on Saturday but the game was played at Collingwood's home ground. Another change may be to move to an adjusted rating system similar to the BBL, where the rating is adjusted before the game to take into account the ground, rest days and other conditions. This would help I think in situations like the West Coast v Melbourne game where Melbourne...

The prediction for the Grand Final is West Coast 53.2% chance to win A lot of games in this finals series have really been not much more than a coin toss, so this could be a close game. I am tipping West Coast  to win based on their experience in 2015 which I think will help their preparation. In terms of ratings, neither team is very interesting statistically. The highest rated winners in recent history were Hawthorn in 2015 (1743 before the Grand Final) and Geelong in 2011 (1772 before). This years Finalists are well outside those numbers. Interestingly the winners of the last two flags have been quite low-rated, with the Bulldogs going into the 2016 Grand Final with a rating of 1586 and Richmond going in with a rating of 1601. Every other winner since 2009 has had a rating over 1700, except Sydney in 2012 with a rating of 1640.

With the second week of the finals done, Elo predicted only 50% of the games again. Again given the Collingwood v GWS game was only slightly in favour of GWS this is not surprising. In the games for week 3 of the finals, West Coast v Melbourne looks like it will be very close. It could just come down to home ground advantage.

Melbourne and GWS are the heavy favourites going into this week. The ratings tell a similar story! Hawthorn (1545) v Melbourne (1609), Melbourne 59.1% chance to win Collingwood (1565) v GWS (1597), GWS 54.5% chance to win

The first week of the finals delivered. Elo correctly predicted 50% of the games, and two of those predictions were a less than 55% chance to win so this is acceptable although 3 from 4 would have been preferable. The finals series is shaping up. Richmond still look the dominant team, and with a rating of 1684 they deserve the tag of favourite.

There really should only be one team that everyone is talking about this year, and that is Richmond. Their rating is so much higher than any other team, they are a clear standout. That being said, what should happen and what does happen is very different. Some changes were made to the system over the bye weekend, and the accuracy is now 73.0% for the 2018 season. The major change is the amount of rating points gained or lost, which is approximately half what it used to be. Finals week 1 Home Rating Away Rating Prediction Richmond 1675 Hawthorn 1554 Richmond 66.7% Melbourne 1594 Geelong 1606 Geelong 51.8% Sydney 1589 GWS 1567 Sydney 53.1% West Coast 1604 Collingwood 1574 West Coast 54.4% The game to look forward to is Melbourne v Geelong. The Cats have gained 9 r...