Analyzing Impact of Goals: Liverpool’s and the English Premier League’s Goal Scorers of the 21st Century
By: Abhijith Mundanad Narayanan
Tags: Liverpool, Soccer Analytics, Data Visualization, Premier League, Soccer

I love Liverpool Football Club (LFC) and football, in that order. Through my years of supporting the club, I have seen great goal scorers in the 21st century. From Michael Owen’s fast-burning rise and fall to Mohamed Salah’s Liverpool kingdom. Since not all goals are equal in the context of a match, a question rose to my mind, whose goals have had the most impact on Liverpool’s English Premier League (EPL) matches? By impact, in terms of changing the state of the game- from a draw to a win or from trailing to drawing a game. To answer this question, I set on my data visualization journey and immediately got stuck, because, there was no data!

With the recent surge in football analytics, the data available from matches is huge. However, for the common man, access to this data is not easy and not free. There are tremendous websites like LFC History, which gives you details from every single match that Liverpool has ever played. However, if one wanted to know “Which LFC player has scored the most goals in the last 10 mins at Anfield in the 21st century?”, there is no easy way to get hold of a structured database to answer such a question.

Since the internet is vast and full of possibilities, I set to work. With the help of a few lines of code in python, the awesome tool of Beautiful Soup, and persistence, I built a database. The story of building this database is for another day. Suffice to say, I created a structured database containing all the goal events (the time of goal and name of the goal scorer), of every English Premier League fixture from 2000 to the current 2020–2021 season.

With this data in my hands (on the computer, of course), I charted my next path. Creating metrics that would help me analyze the impact of goals. I started with a basic attribute of Goals per 90 minutes. The attribute is clean enough, easily interpretable, and removes bias towards players who play a lot of minutes. Next, I tried to quantify how many points a goal, thereby the goal scorer, won for Liverpool. If a goal was the final goal in a game and it was the game-defining goal, i.e. leading to a draw or a win, the player was awarded +1 or +3 points respectively. The points won by a player was normalized by dividing it by the number of appearances. Using the two metrics defined to visualize all the LFC goal scorers in the 21st century, we get the wonderful plot below.

In all the plots below, the size of the individual blobs correspond to the total goals scored by the player. Larger the blob, higher the total number of goals.

Impact of LFC Goal Scorers in 21st century: Points won

The most impactful goal scorer is not even debatable: Fernando Torres. The rate of points he won for Liverpool with crucial goals is second to none.

I was genuinely surprised by the results. The most impactful goal scorer is not even debatable: Fernando Torres. The rate of points he won for Liverpool with crucial goals is second to none. Riding at the top of his chasing pack is Mohamed Salah, comfortably ahead of Sadio Mane and Bobby Firmino, his contemporaries. Interestingly, the plot seems to show that Daniel Sturridge’s goals have had a much bigger impact on points won by LFC than Luis Suarez’s goals, though the latter has had astonishing seasons.

Once I started this journey, I was in no mood to stop. The result of a match is dependent on the defense and the rest of the team’s performance as much as on an individual’s goal. Hence, one can be a little more lenient on how the impact of a goal is rated. To this end, I introduced a new metric called the Game-Changing Goal. A game-changing goal is the one that takes the lead for the team or ties the match. Each goal of a player was assigned the status of a game-changing goal or not. Similar to the normalized points-won metric from before, game-changing goals were also normalized, but this time dividing by the number of appearances by the player for the club. Visualizing game-changing goals to Goals-per 90 returned the following plot.

Impact of LFC Goal Scorers in 21st century: Game changing goals (minimum 15 goals)

The most impactful Liverpool goal scorer of the 21st century: Fernando Torres. However, Mohamed Salah can change that. He is hitting his peak playing years and he is in sublime form this season. I have a feeling he will overtake Torres soon.

Again, there is no competition on who has had most impact on games. Torres! However, Mo Salah enters the picture as a close second, with 0.4 game-changing goals per appearance.

In summary, there is no doubt who is the most impactful Liverpool goal scorer of the 21st century: Fernando Torres. However, Mohamed Salah can change that. He is hitting his peak playing years and he is in sublime form this season. I have a feeling he will overtake Torres soon.

For general public consumption, I made a webapp where you can have a look at your favorite teams’ goal scorers! Check it out here! My twitter feed will keep you posted with new fun football analyses. Give a follow here!

This post illustrated the most impactful goal scorer for Liverpool. However, I had collected data for all the EPL clubs from the 2000–2001 season to 2020–2021. For general public consumption, I went ahead and made a webapp where you can have a look at your favorite teams’ goal scorers! For instance, Tottenham Hotspur fans can confirm what they already knew. Harry Kane is their greatest (and most impactful) goal scorer. However, who comes second? I have the answer for you. It is pretty crowded! Nevertheless, Heung-Min Son is gradually inching ahead of Jermain Defoe and Robbie Keane.

Impact of Tottenham Goal Scorers in 21st century: Game changing goals (minimum 15 goals)

We have seen that Torres is the undisputed goal scorer with the most impact for LFC in the EPL. How does he fare against the EPL greats like Thierry Henry, Sergio Aguero, et. al? Well, again, you know I have the answer. The plot below gives your answer:

Impact of the great EPL Goal Scorers in 21st century: Points Won (minimum 30 goals)

In the impact of his goals for his team, Fernando Torres leads every single great EPL goal scorers of the 21st century

Impact of the great EPL Goal Scorers in 21st century: Game changing goals (minimum 30 goals)

The analysis leads to the surprising observation regarding the impact of Fernando Torres on Liverpool. Not only does he lead amongst Liverpool’s goal scorers, he easily surpasses every great EPL goal scorer of the 21st century! His acrimonious departure mid-season to Chelsea FC and his subsequent sharp drop in form has lead to severe underappreciation of his contributions for LFC. Moreover, I believe even his standing amongst the generally accepted greatest of the EPL is undervalued.

The plots shown here are a bit crowded with blobs and hard to discern beyond the top players. You can visit this page to have a look at the visualizations yourself here: https://goalscorers-21st-century.herokuapp.com/. There is one for every team that played in the English Premier League along with a combined visualization to contrast different players. Moreover, the visualizations are interactive with a lot of customizations.