The most obvious way to calculate the age of any given Premier League squad is to look at the roster and take a straight average of the players that you find on their roster. This is certainly not an inappropriate way to evaluate but it has some obvious flaws. If the club lists a number of young players who never actually feature in meaningful competition then the club's "average age" would look younger than it actually is. Likewise, if the club employed a few veteran reserves in the event that a member of the preferred eleven were to be out injured for an extended spell but that player never really played much then calculating a straight average would make the club look older than it effectively is.
The solution that we have developed to help navigate the effective age of each club in the Premier League is Minute Adjusted Age. The concept is pretty simple, attach an age to each minute played at each position for a given club and then divide by 37,620 (11 positions on the field x 90 minutes played x 38 matches). This gives us as good a sense as we can get as to the effective age of each club by weighting the average based on the ages of the players who are actually competing week-to-week rather than the ages of the players on the roster overall.
As we evaluate each team, we'll discuss how each club looks going forward as well. For instance, Arsenal was the sixth youngest team in the Premier League based on Minute Adjusted Age AND they ended the season even younger than that as 20-year-old Hector Bellerin took over the starting right back role from 29-year-old Mathieu Debuchy and 24-year-old Francis Coquelin tood over a holding midfield role from 33-year-old Mikel Arteta and 31-year-old Mathieu Flamini. Heading into next season, Arsenal's overall roster may not look any different as each of these players will likely still be present in some capacity but the club's Minute Adjusted Age will likely go down as Bellerin is likely to improve on his 1562 minutes played and Coquelin on his 1663 minutes played. At center back, 24-year-old Gabriel is likely to find more than his 349 minutes in the Premier League season and bring down the total even further as he replaces either 30-year-old Per Mertesacker or 29-year-old Laurent Koscielny. It could conceivably go the other direction as Gabriel picks up some of the 1571 minutes that 20-year-old Calum Chambers wasn't quite ready to handle.
Overall, we hope that using this measure of squad age will help supporters understand how urgent it might be for their favorite club, or at least the one they happen to be reading about at the moment, to start overhauling the roster or risk dropping down the table as Fulham did the season they were relegated with veterans Mark Schwarzer (40), Brede Hangeland (31), Sascha Reither (30), Dimitar Berbatov (32), John Arne Riise (31), Damien Duff (34), Steve Sidwell (30), Aaron Hughes (33), Georgios Karagounis (36), and Chris Baird (31) all playing significant roles. Every one of those players was at serious risk of declining individually and the combination of what were probably minor drop-offs from each player with no corresponding improvements from younger players on the roster - because there weren't any playing significant roles, was enough to push the Cottagers from mid-table to relegation fodder in the blink of an eye.
As we look at a club like Manchester City, we will see that while the risk of relegation is almost nil, the potential for a drop-off from the oldest team in the Premier League based on Minute Adjuted Age is significant. If they don't refresh significantly over the summer they risk a number of their players regressing slightly with no corresponding uptick in performance from younger players because, like Fulham in 2012-13, there are precious few young players with projectable upside playing a significant role at the Etihad.
We hope you find this a useful addition to your understanding of each club's position heading into the summer, our thanks to Galin for doing the dirty work and compiling the number for each of us to integrate into our respective analyses.
Below are the numbers for each team.