The Post-Bubble Effects on NBA Players’ Healths

A trending narrative that has emerged in the Playoffs is that regarding the players’ deteriorating healths, instantiated by the injury-riddled postseason. NBA All-Stars, such as Jamal Murray, Kawhi Leonard, Donovan Mitchell, and most recently Giannis Antetokounmpo, have sustained injuries which have had lasting impacts on their respective teams’ Playoffs standings. Media outlets as well as NBA players themselves have come out and denounced the NBA for letting this happen.

James’ comments on the NBA continuing with the season as early as in December

The basic logic backing these claims here is that the league wrapped up a few months later than it would have — due to the season being suspended due to the pandemic and then restarting later. Thus, as some players finished their seasons in October and had to come back on court as early as December, it caused them not to have the appropriate amount of ‘rim rest’.

And so, I will be crunching the numbers to see to the truth of this narrative. The GitHub repo of this project can be found here.

Data Used

As always, I’ll be using the Stats NBA API for this project. You can check out data.py in the repo to see how I came across the data. I’ve also included .csv files showing the data I pulled.

Analysis

The first metric I’ll be looking at is the average minutes played by an NBA player in the past year coming in to the Playoffs. The ‘past year’ here quite literally refers to the past 365 days, and not the season itself. The two datasets I pulled for the same conform to the players’ minutes played in the 365 days prior to the 2021 Playoffs as well as to the 2019 Playoffs (I chose 2019 as 2020 would’ve been difficult to account for due to the pandemic).

Interestingly enough, I found the average minutes played by an NBA player in the 365 days leading up to the 2021 Playoffs to be:

1117.71633 minutes

The similar stat-line for the 2019 Playoffs was:

1255.89286 minutes

Clearly, the players on average played many more minutes in 2019 than they did in 2020. I could think of a couple of reasons as to why this is:

• The 72-game 2020–21 season obviously affected the minutes played by players as they played 10 games (potentially 480 minutes) less.
• The injuries themselves could have plausibly caused the average to go down in 2020–21, as the injured players played for less time.
• Some players and teams didn’t show up in the Bubble for various reasons. Eight teams, including the Cleveland Cavaliers and Golden State Warriors and more, were not part of the Bubble. Players such as Trevor Ariza and DeMarcus Cousins opted out of playing in the same. This could very clearly bring the average down.

The Bubble-Adjustment

The last point could be an issue. The player data for the 2020–21 season should be adjusted to include only the players who played in the Bubble. Perhaps a more specific stat would include the average minutes of the players in the Bubble in 2020 and the players who played in the 2020–21 Regular season. I’m going to simply adjust the 2020–21 average minutes played to include only the players who played in the Bubble. The result:

1163.18256 minutes

Only a bit higher, but not helpful in answering our question.

To give the trending narrative one more chance at redemption, one can criticise these results by claiming that the span of 365 days would be way too wide to spot any differences. I should thus be using the last 6 months instead of 12. Results for the 2020–21 season:

897.19846 minutes

And similarly for the 2018–19 season:

1121.89811 minutes

And there you have it. The Bubble did not cause players to play more on an average within a small timeframe, as can be seen by these averages. It, in fact, gave them more time to rest and recuperate in the form of having them play lesser minutes.

Individual Player Analysis

I’m still not satisfied with the answer. Another critique here could be that the All-Stars who have been injured carried a considerably significant workload (i.e., played more minutes) than others, and their efforts could have gotten incorrectly averaged out due to their minority. Well, here are select stats for some of the players who got injured this Playoffs:

Individual Player Data

As can be seen, there isn’t a direct correlation between the minutes the player played and his injury. Notes from this table:

1. Only Chris Paul and Jaylen Brown played more heavily within the past 6 months (as well as 1 year) before the 2021 Playoffs as compared with the 2019 Playoffs. While Brown’s injury could plausibly be fully accredited to the amount of extra time he played, Paul’s age could also be a factor for his.
2. Kyrie Irving did not attend the Bubble, and thus doesn’t belong in this discussion at all.
3. Kawhi actually did play for more minutes for the year coming into these Playoffs, but had more time off in the past 6 months.
4. The rest of the players, surprisingly, played for more minutes in both 6 month and 1 year periods before the 2019 Playoffs.

Conclusion

Not only does the data show that the condensed season had nothing to do with the injuries, it in fact shows that players on an average ended up playing less minutes than they would have in a normal 82-game season. Why did this narrative come about, then? Firstly, the research done here doesn’t provide a conclusive proof on the matter. Of course, more factors than the mere minutes played must go into the game. As LeBron James stated earlier:

“I always think from the moment we entered the bubble to now, it’s been draining, […] Mentally, physically, spiritually, emotionally draining.” (Source: ESPN)

Secondly, the data still shows that there were more injuries this season. The most common assumption would be to blame the irregular circumstances. However, I do believe that there could be other reasons that led to the same.

Future Work

For lack of a better method, I manually pulled the ‘minutes played’ stat for each active player per season. I’m still discovering the NBA API, and have a long way to go to perfect the same. I also want to gather more diverse data in order to answer the ‘why’ of these injuries. Perhaps, the scoring boom over the past few years has caused players to be more offensive, which itself would lead to more injuries.