EPL Analysis and Gameweek 7 Prediction
By: Abhijith Chandradas
Tags: Football, Data Visualization, English Premier League, Soccer, Data Analysis

EPL Analysis and Gameweek 7 Prediction

A data driven attempt in predicting English Premier League results using xG Statistics

This is an article on my EPL Prediction series. You can check out the prediction for previous Game Week and how it held against the actual performance here.

Expected Goals or xG is the parameter used for prediction. If you are interested in understanding the algorithm for prediction, I recommend that you check out this article where it is explained in detail.

Analysis up to Game-week 6

After 6 game weeks, 6 points separates the top 15 teams there are no clear title contenders as of now. The league is highly competitive and there are no unbeaten sides. The only unbeaten sides up to Game-Week 5, Everton and Aston Villa tasted their first defeats in Game Week 6.

Both the Mersey-side teams with 13 points top the points tally. Everton enjoys the top spot on the table, thanks to Goal Difference.

xG Scored and Conceded per match (Image by author)

The defending champions Liverpool is the best attacking team creating more than 2.5 xG per match, no other team manage to create more than 2 xG per game. The Spurs, Leeds, Toffees and the Villans average more than 1.5 xG per game.

On the other side of the spectrum, WestBrom struggles to create goal scoring opportunities with xG around 0.5 per game. To make matters worse, West Brom also has the most porous defence. Wolves and Burnley also struggles to create chances to score but they are able to partially compensate for it with their good defensive capability as indicated by low xG conceded.

Everton, Brighton, West Ham and Southamton possess the best defence conceding around 1 xG per game. Despite their disciplined defensive unit, Brighton has been unlucky in the tournament so far conceding 12 goals averaging 2 goals per game.

Image by author

Based on xG Scored and xG Conceded, teams can be grouped into 4 quadrants as shown in the above graph. The horizontal dotted line shows the average xG scored per game. Teams above the horizontal dotted line are strong attacking sides and the teams below weak in attack.

The vertical dotted line shows average xG conceded per game, teams to the left of have strong defence and the teams to the right have week defence.

The aim all teams should be in Q2 where both attack and defence are better than the average. For example, Burnley is a great low block defensive side in the leage. In Game Week 6, they were up against the Spurs who are the leading goal scorers this season. Burnley’s defence did a great job at containing the Spurs attack, they limited the shots on target to zero during the first half and the only goal of the game came from a set piece. However, Burnley ranks among the lowest in chance created. Unless they take proactive steps to improve their strike force, it is difficult to advance in the league table.

Image by author

Some teams are able to compensate for their weakness in one area with their strength in the other to emerge with a positive delta xG(difference between xG scored and xG conceded. We can look at the Leeds and Southampton. Bielsa’s team has not fared well in containing opposition attack but are able to create goal scoring opportunities to compensate for the former. On the other hand, the Saints defensive unit hardly makes errors but does not do a great job in creating chance for Ings and company up front to score. But their defensive capability can make up for the lack of creativity up front.

Game Week 7 Predictions

Before proceeding to the predictions, let me clarify that this is a very simple algorithm just based on past xG, so only baseline performance can be expected. The sample size is very small and also a lot of other important factors are not considered. The algorithm will evolve in the future incorporating more factors as the season progresses.

Predictions for Game Week 7 are provided in the table below.

The absolute value of GD shows the competitiveness of the match. The higher the value, more one sided the match is expected to be and higher the accuracy of prediction.

The lower the value of GD, the more the match could be anybody’s game. Positive value of GD means Home win and Negative value means Away team win.

Game Week 7 Prediction (Image by author)

In the upcoming fixture, we can expect plenty of closely contested matches. Newcastle vs Everton is the only match where more than 0.5 xG difference can be observed. Toffees are very likely to leave St. James’ Park with 3 points. Fulham has a fair chance at their first win of the season this week against the Sparrows. The defending champions can expect to win their home outing against the resurgent Hammers who have made Man City and Spurs drop points. The title contenders, De Bruyne and company is expected to steamroll over the Blades defence.

Liverpool vs West Ham is expected to produce the maximum number of goals. On the other hand, the battle of Defences-Wolves vs Crystal Palace is expected to be the lowest scoring match.

Update: Actual Vs Prediction

Predicted xGD vs Actual xGD (Image by author)

The algorithm did a very good job in predicting the direction of 9 out of 10 games of the GameWeek. The prediction was wrong only in Newcastle vs Everton match. Our algorithm predicted Everton to steamroll over the Newcastle side. However, the Magpies had the better of the Toffees handing them the second defeat in a row. The Toffees were certainly weak side due to the absence of the trio of James Rodriguez, Richarlison and Digne, which could not be factored in the xG model.

The predictions were not accurate with respect to the magnitude. In all matches, the dominating team able to create more goal scoring chances than that predicted. The difference was most prominent in Aston Villa vs Southamton, Tottenham vs Brighton, Newcastle vs Everton and Leeds vs Leicester matches. These matches also had penalty kicks awarded in favor of the dominating team.