Is the NFL's 'Next Man Up' Mantra Really Working?

By Steve Moser, Managing Director, High Performance Associates

Tune into practically any Monday morning press conference and you’re bound to hear an NFL head coach utter the phrase ‘Next man up’ when going through the injury report.

The idea behind this phrase is that teams can weather any injury storm as their benches are so strong that coaches can just put the next man in and get the same performance outcomes. This sounds great in principle, but is it a reliable mantra or just a meaningless catchphrase? Put simply, do injuries really matter?

There are certain statistics that every NFL team know to be strongly correlated to their winning percentage; point differential or turnovers to name but two. However, as the focus on athlete health, injury prevention and recovery continues to grow in importance, more data is now available to analysts and sports science staff. This is giving event greater insight by allowing them to look beyond on-the-field performance, and be able to analyse what happens off the field too.

Using data provided by ManGamesLost, I ran regressions to analyse how significant the trend was between injuries and a team’s winning percentage over the past three seasons.

Interestingly, the results demonstrated a significant trend of an increasing correlation between man games lost due to injury to winning percentage, over the previous three seasons.

2015-2016 – Correlation: 81.1%

2016-2017 – Correlation: 90.5%

2017-2018 – Correlation: 96%

Looking at the data, it can be concluded that the relevance of players missing games due to injuries increasingly impacts winning percentages.

In comparison to other statistics, when we look at the correlation to point differential or turnover differential, the significance every year will be 99.9%. In the 2017-2018 season, however, we found a 96% correlation between injuries and winning percentage – a percentage that has been steadily increasing.

However, we must bear in mind that these variables are certainly not independent of one another. Man games lost due to injury can of course have negative effects on your point or turnover differential. Nevertheless, these findings underline the importance of keeping your players on the field, or if injured, ensuring they can recover as soon as possible.

These conclusions can raise questions in a team regarding their performance staff. Whilst avoiding injuries altogether in any sporting industry is unfeasible, the question stands – how many teams can confidently say they dedicate as much time and resources in protecting their players and preventing injuries, as they do to protecting the football and preventing turnovers?

As the data shows, ensuring team injuries and recovery time is kept to a minimum is directly correlated to the health of the win-loss column.