It's July 21, 2021. Two of the best international football teams in the world gather at Wembley Stadium in London. England, the fourth-best team in the world according to FIFA metrics, is up against Italy’s seventh-ranked squad. It’s the final match of the 2020 European Championships, a highly awaited tournament delayed a year due to the COVID-19 pandemic.
England vs. Italy. The teams remain in a tie after 120 minutes, and when the final whistle blows, both teams know what's ahead of them: a penalty shootout.
Field players and goalkeepers alike dread penalty shootouts. "The beautiful game" might be beautiful, but it can also be cruel: there is nothing worse than losing in a penalty shootout.
Sidenote: It's worth mentioning that stopping a penalty kick is one of the hardest thing to do in sports. Want to know why players go so crazy when a goalkeeper gets their hands on a shot? Because it is genuinely very difficult. In fact, a professional player placing a speedy shot toward the outside of the goal can be physically impossible for a goalkeeper to stop if the goalkeeper fails to move in the correct direction before it's kicked.
Back to the Euro final. In the final minute of the match — right before the penalty kicks started — English Manager Gareth Southgate brought in two young upstarts: Marcus Rashford and Jadon Sancho. Why did he do this? The best guess is that he wanted them to be eligible penalty takers (FIFA rules dictate that only players on the pitch at the end of the match can take a penalty in a shootout).
I'll save you the theatrics: England loses. Three of their players miss penalties, including Rashford and Sancho.
English fans take to social media. Many of the posts are blatantly racist (all three English kickers who missed were Black: Rashford, Sancho, and Bukayo Saka). Those posts, of course, were deplorable.
But some more reasonable individuals on social media raised an interesting quandary: are substitutes less likely to score on penalty kicks in penalty shootouts? Was Southgate’s strategy statistically ill-advised? Those are the question this study seeks to answer.
Or, to put it bluntly: can fresh legs kick? That is the topic of my latest statistics paper.
You can read the full report below. It's full of tables, and I've made attempts to make it as readable as possible. But in case you aren't interested in that, I've organized some conclusions here.
Yes, last-minute substitutes perform worse on penalty kicks. And yes, it's statistically significant.
I looked at 1,671 different penalty shootouts across 162 matches dating back to the year 2000. I chose 11 different tournaments and competitions from all over the world and looked at every match that ended in a penalty shootout.
For each penalty kick, I tracked how long the player was on the pitch. If he played for 5 minutes or less, he would be counted as a "last-minute substitution." Any player with more than 5 minutes of experience in a given match is treated the same for the purpose of my study, no matter if they were a substitute or a starter.
The table below displays the success rate for each group.
Last-Minute Substitution Group
That's a different of almost 15%.
My next step was to perform a significance test. Basically, I threw these values into a complicated mathematical formula, and my computer spit out a number. We compare that number to a critical value, and if it is within a critical range, we determine it's significant. You can examine that in the figure below.
Since that black line (our value) falls to the left of that red line (the critical value), we determine it is significant.
My data is located in an open, accessible database
I hold the firm belief that any researcher or statistician should be honest and open about the database used in their studies. In the searchable database below, you will find every penalty kick examined in my study.
In the "Make/Miss" column, any successfully converted penalty kick is coded as 1, while an unsuccessful penalty kick is coded as 0.
Different competitions differ in how often a penalty kick is saved or converted
I evaluated, in total, 159 occurrences of 11 different competitions. You can evaluate how often players missed or converted penalty kicks in each competition with the visual below.
Questions? Comments? Disagree with my methods?
Please, reach out and tell me! I'm trying to get better. My contact information is readily available.