MLS Fantasy Boss A Fantasy MLS Community
The following predictions are based on the ELO ranking system. This system was first used in chess to calculate the skill level of players and predict the most likely winner. It’s a good system, but soccer is not chess because soccer can end in a draw. Fortunately chess also allows for a draw and the ELO system is setup to factor this into its calculations. I’m using a modified formula that tries to predict the chance that a team will come away with points. This includes not only wins, but also draws.
The system starts each new team at a score of 1500 and then adjusts their rating as the season goes on. My current team scores include data from 1996-2017 (with some adjustment to account for the changing MLS win/draw rules). The following are not included: Domestic tournaments, preseason friendlies, and international games. These scores are used to rank teams for my Power Rankings table and the values are now included in the chart.
2018 Running total of Prediction Success
- 2018 Overall: Correct = 34 Incorrect = 17 Draw = 14. Total accuracy of predicting teams earning points = 74%
- Round 7 Predictions: Correct = 5 Incorrect = 3 Draw = 3. Total accuracy of predicting teams earning points = 67%
2018 Round 8 Predictions and Power Rankings
Predictions for Round 8
Power Rankings for Round 8
I always wondered about the best way to tell how well any probability model is working. Rather than look at %correct, is there a way to test if your predictions are significantly different from the true probabilities? For example, you say Columbus has a 66% chance of getting points. If they lose, that doesn’t necessarily mean you were wrong. They did, after all, have a 34% chance of losing.
Inserting suggestion. The ELO model attempts to be self correcting over time, and the one variable I look at during the off season is the home field advantage modifier.