Our prediction of the FIFA World Cup 2018 consisted of three stages. Firstly, we determined the quality of every selected player using our Euro Player Index (EPI). The EPI is derived from the renowned Euro Club Index (ECI) and measures the individual contribution of every player to the team performance. For players outside of our database, we used a model to predict their quality using club and player-specific information, like the level of the competition, playing time, age and number of goals and assists.
Secondly, Remiqz calculated a weighted average EPI for all participating countries. Since not all 23 squad members are used equally as often, we looked at past World Cups to determine the expected playing time of every squad member. For instance, the first-choice goalkeeper played 98% of the available playing time in past tournaments, hence his EPI gets more weight than the EPI of the other two goalkeepers in the squad.
Finally, the match odds depend on the playing strength of both teams, the home advantage (for Russia) and the match performance of the teams. The playing strength is given by the weighted average EPI-values. We assume that the match performance varies according to a normal distribution. This way it is possible to calculate the probabilities of the different match results (win, draw, loss). Our predictions follow from Monte Carlo simulations based on these match odds.
The Sophisticated Prediction Contest consists of three separate competitions: predicting (1) the overall tournament, (2) the group stage and (3) the knock-out stage. As expected, our method proved to be most accurate in the group stage: Remiqz finished first out of 24 entries. In the knock-out stage, our prediction took a hit when Russia beat Spain on penalties in the Round of 16. Even though the tournament is still running, our prediction of the overall tournament will result in a silver medal (out of 31 entries) no matter what happens next. We look forward to participating in the next sophisticated prediction contest!