Football technology has grown significantly over the last decade or so and has become a prominent feature in the sport over time. Apart from the traditional statistical breakdown of performances, analytics have gone on to play a key part in football and parameters such as xG (Expected Goals), xG90 (Expected goals per 90), xA (Expected assists), and more, have become more and more reliable metrics used to draw conclusions over a player's performances over a period of time.
xG is an advanced metric to deduce the number of goals a player could or should have scored based on a number of circumstances up until that point of the season or through the 90 minutes of a game. In short, it is a study of the quality of chances a player has received. It can also be used as a metric to define how good or bad a player's finishing ability is. British sports analytics firm Opta defines the metric in this manner:
"Expected goals (xG) measures the quality of a shot based on several variables such as assist type, shot angle and distance from goal, whether it was a headed shot and whether it was defined as a big chance."
As we have reached the halfway point of the Premier League season, here, we take a look at the Premier League's xG leaders and try to list the players who have overachieved or underachieved based on the chances they have received.
Note: The following list only contains players who have played a minimum of 15 Premier League games in the 2019/20 season.
#5 Chris Wood - 10.08
A relatively surprising name to begin the list off with, Burnley's Chris Wood makes it at fifth place by the skin on his teeth. Mohamed Salah's 16 appearances so far have yielded an xG of 10.00, with Wood edging him out by just 0.08.
The 28-year-old has played 18 times for the Clarets this season, scoring 7 times, all seven of which are non-penalty goals.
His xG, on the other hand, is 10.08 in the 1491 minutes he's played so far. This essentially means that he has underperformed by 3.08, wherein he could have added 3 more goals to his name if he'd converted approximately 3 more relatively easy chances that went missing.
The New Zealand international has an xG90 of 0.61, the same as Chelsea's Tammy Abraham, having played one game lesser than the Blues' striker.
#4 Tammy Abraham - 10.35
Tammy Abraham has had a sensational season so far for the Blues, and is expected to be the long-term fix for Chelsea's cursed No.9 role. The London club haven't had the greatest luck with talismanic strikers for a few years now bar the odd exceptional talent. Abraham looks to change that and is fresh off another superb strike to down cross-town rivals Arsenal in the London derby.
The Englishman has played 19 league games this season scoring 12 non-penalty goals to lead the Blues' charge for a Champions League spot. His xG, though, is 10.35, which means that he overperformed his expected goals metric, albeit by a small margin of 1.65. Abraham's finishing has been one of his greatest qualities and the metrics back up this claim.
Having played 1518 minutes so far, his xG90 of 0.61 isn't the greatest in the league but is certainly up there with many more notable names.
#3 Jamie Vardy - 11.48
Jamie Vardy just doesn't appear to be slowing down. Ageing as beautifully as fine wine, the Leicester City striker has had an astounding season so far, scoring 17 goals in the 19 games he's played so far. Out of his total goal tally, only 3 came from penalties, in a total of 1710 minutes. The Premier League winning-striker has looked unstoppable this season, with defences having nightmares trying to shut him out due to his unbelievable athleticism and superb finishing.
Speaking of finishing, the fact that he's notched 17 goals despite having an xG of just 11.48 reiterates his reputation as one of the fiercest strikers in the Premier League. The 32-year-old has outperformed his xG by a mind-boggling figure of 5.52, highlighting his ability to finish from extremely acute angles, long distances and occasionally poor service from his teammates.
Vardy has the ability to make something out of nothing due to his direct approach to the game. And, as highlighted by him overshooting his xG by 5.52 (and some glorious goals scored by the striker this season), one thing is for certain: Jamie Vardy is unquestionably the best finisher in the 2019/20 Premier League campaign at the midway point.
#2 Raheem Sterling - 11.59
Manchester City's crown jewel, Raheem Sterling has been one of the best players in the Premier League over the last couple of seasons and was central to Pep Guardiola's domestic reign. The former Liverpool player has appeared 19 times so far for the Cityzens, scoring 11 times, all of which are non-penalty goals over 1680 minutes.
Goalscoring was something that Sterling was criticised for notably until Guardiola's arrival in Manchester. The Catalan's system enabled the Englishman a lot more freedom to hover around the 18-year-box and pushed him to find more dangerous spaces from where he can find the back of the net.
His xG for the season is at 11.59, which is almost in keeping with his actual tally of 11 goals. Sterling's finishing has improved significantly and considering how sustainable his current scoring pace seems to be, he could have a prolific second half of the season to look forward to.
Albeit his xG90 of 0.62 is higher than anyone on this list so far, it is still a far lesser figure when compared to Sterling's teammates Sergio Kun Aguero and Gabriel Jesus, who have xG90s of 0.88 and 0.91 respectively.
#1 Marcus Rashford - 13.43
Manchester United's Marcus Rashford has, by some distance, accumulated the highest xG up until the midway point of the Premier League season. The prodigious striker has blown hot and cold and has often failed to convince the world of his ability to lead the line by himself.
Under the tutelage of Ole Gunnar Solskjaer though, this no longer seems to be the case. The Englishman has played both at centre-forward and left-wing this season and has already racked up 12 goals so far, including some crucial ones against Manchester City, Chelsea, Tottenham Hotspur, and the champions in waiting, Liverpool.
4 out of his total of 12 goals came from penalties, but despite having the highest xG in the league, he is still 5 goals away from top-scorer Vardy, signifying the difference in levels of finishing and decision making in the English strikers. Rashford amassed 1710 minutes in 20 appearances the league and managed an xG90 of 0.69, all of which are more than anyone on this list.
Although he has underperformed by a figure of 1.43, his consistent displays and the numbers behind them suggest that he is set to have what could potentially be his best goalscoring season in the Premier League.