Bruce Dias 
The modern era represents something of a golden age for fans of Football data, with a greater array of stats and metrics available than ever before. Few areas of the game are free from the watching eye of the statisticians, with interceptions, ball recoveries, and total meters covered being just a few of the new measures commonly discussed amongst fans and punters assessing the very best New betting sites.
Amidst this ever-expanding collection of measurements, the one stat most representative of this data explosion is that of Expected Goals or xG. First introduced by Opta in 2012, this stat quickly caught on with fans – inspiring several books on the subject and becoming a regular topic of discussion on the leading football analysis shows.
With that popularity in mind, and have now moved past the mid-point of the season, this seems an opportune time to assess the xG performance of the 20 sides in the English Premier League, looking at xG for, xAgainst, and xPoints.
What is xG?
First things first, what exactly is xG?
Whereas fans have long been used to stats such as total shots and shots on target, xG aims to go a step further in assessing not only the total number of chances created but the quality of those chances.
In xG, each chance created is handed a numerical rating according to how often the chance could be expected to result in a goal, using data collected for similar chances across 1000s of games.
For example, a chance from 6 yards out, with only the keeper to beat, would receive a far higher xG figure than a speculative effort from 30 yards. By combining the xG values for all chances created in a game, a figure is then produced to represent the number of goals a team would be expected to score, given the quality of the chances created.
xG Against is then simply the number of goals a side would be expected to concede given the quality of chances they conceded, whilst x Points combines the two to represent the number of points a side would be expected to achieve based upon their xG For and xG Against stats. Below figures are correct as of 28/02/2023.
Expected Goals For Analysis
Top 5 Overachievers
1. Leicester City: xG = 26.36, Actual Goals = 36, Difference = 9.64
2. Tottenham Hotspur: xG = 37.97, Actual Goals = 46, Difference = 8.03
3. Manchester City: xG = 57.58, Actual Goals = 64, Difference = 6.42
4. Arsenal: xG = 47.91, Actual Goals = 52, Difference = 4.09
5. Fulham: xG = 33.16, Actual Goals = 36, Difference = 2.84
Sitting down in 14th position, Leicester City nevertheless tops the overachiever’s table, having scored almost ten goals more than would be expected from the quality of the chances they have created. If unable to maintain this stat over the remainder of the season, they may yet find themselves looking over their shoulders.
Top 5 Underachievers
1. West Ham United: xG = 32.03, Actual Goals = 23, Difference = 9.03
2. Liverpool: xG = 46.86, Actual Goals = 38, Difference = 8.86
3. Everton: xG = 25.73, Actual Goals = 17, Difference = 8.73
4. Chelsea: xG = 31.16, Actual Goals = 23, Difference = 8.16
5. Newcastle United: xG = 41.87, Actual Goals = 35, Difference = 6.87
West Ham United finds themselves perilously close to the relegation zone, but the xG stat suggests there is cause for optimism heading into the second half of the season. If able to keep up their quality chance creation process, the Hammers should soon be out of trouble.
Expected Goals Against Analysis
Top 5 Overachievers
1. Fulham: xGA = 46.35, Actual Goals Against = 31, Difference = 15.35
2. Newcastle United: xGA = 25.56, Actual Goals Against = 15, Difference = 10.56
3. Liverpool: xGA = 37.77, Actual Goals Against = 28, Difference = 9.77
4. Everton: xGA = 40.60, Actual Goals Against = 32, Difference = 8.60
5. Crystal Palace: xGA = 37.17, Actual Goals Against = 31, Difference = 6.17
Fulham is currently flying high in 6th position and faring comfortably with the best of the newly promoted sides. However, purely on the xG Against stats, that may be something of a false position, with the Cottagers having the worst xG Against figure of all 20 sides in the division.
Top 5 Underachievers
1. Southampton: xGA = 34.54, Actual Goals Against = 41, Difference = 6.46
2. Bournemouth: xGA = 42.92, Actual Goals Against = 48, Difference = 5.08
3. Leicester: xGA = 37.48, Actual Goals Against = 42, Difference = 4.52
4. Tottenham Hotspur: xGA = 30.61, Actual Goals Against = 35, Difference = 4.39
5. Brighton & Hove Albion: xGA = 26.87, Actual Goals Against= 29, Difference = 2.13
Southampton is the side in deepest trouble after Match Day 24, sitting rock bottom of the standings and 4 points adrift of safety. Purely from a defensive standpoint, however, they are not without hope, with their xG against stat ranking 11th overall in the league. If able to get something going at the top end of the pitch, they may yet stage a revival.
Expected Goals Points Analysis
Top 5 Overachievers
1. Fulham: xPoints = 27.99, Actual Points = 39, Difference = 11.01
2. Arsenal: xPoints = 48.70, Actual Points = 57, Difference = 8.30
3. Manchester United: xPoints = 43.04, Actual Points = 49, Difference = 5.96
4. Tottenham Hotspur: xPoints = 39.51, Actual Points = 45, Difference = 5.49
5. Nottingham Forest: xPoints = 22.09, Actual Points = 25, Difference = 2.91
Given that huge overperformance versus their xG For stat, it is no surprise to learn that Fulham has registered the biggest discrepancy between xPoints and Actual Points. Will Marco Silva’s men be able to keep this up? Or will the predicted points and actual points draw closer together as the season wears on?
Top 5 Underachievers
1. West Ham United: xPoints = 35.24, Actual Points = 23, Difference = 12.24
2. Leeds United: xPoints = 30.31, Actual Points = 22, Difference = 8.31
3. Southampton: xPoints = 25.26, Actual Points = 18, Difference = 7.26
4. Brighton & Hove Albion: xPoints = 40.71, Actual Points = 35, Difference = 5.71
5. Everton: xPoints = 23.49, Actual Points = 21, Difference = 2.49
A similar pattern emerges when looking at the sides who have not achieved as many points as their performances suggest they should, with xG For underachievers West Ham United also topping the pile in the xPoints underachievers table. Time is beginning to run down if West Ham is to convert xG performances into real points, but on balance, the figures suggest they may simply have been unlucky so far this season.
