Abstract/TLDR: The overwhelming majority (~62%) of ACL injuries occurred in the off/preseason. Of the 15 injuries that have occurred during the season, two have happened on a Thursday night game. This is slightly concerning considering the amount of games happening on Sunday far exceeds the number of games on Thursday, but really isn't enough to imply a correlation.
Background: Alright, we all know that ACL injuries are on the rise. I am part of the fan base most recently reeling as a result of a star going down from a tear, so I've been following all of the Geno Atkins threads. In the main "Geno Atkins out for the year" thread here in /r/NFL, someone asked if there was potentially any correlation between injuries and short week Thursday night games. I was curious, so I compiled data on all 39 players who have fallen this year due do an ACL tear.
I got the list of players from here.
OFFSEASON (24 injured in offseason/39 total)
Linebackers (4/6): Victor Butler, Darius Fleming, Jason Phillips, Jonas Mouton
OL(2/5): Dan Koppen, Bryan Bulaga
DE(4/4): Melvin Ingram, Greg Scruggs, Phillip Hunt, Will Smith
CB(3/3): Aaron Berry, Chris Culliver, Richard Crawford
WR(8/10): Jeremy Maclin, Armon Binns, Arrelious Benn, Denario Alexander, Joseph Morgan, Vidal Hazleton, Keolah Pilares, Kevin Elliott
FB(1/1): Mike Zordich
TE(1/1): Dustin Keller
FS(1/1): Stevie Brown
REGULAR SEASON (15/39): For this section I've noted if it occurred on or close to a bye week, Thursday night game, what week the injury occurred on, and who they were playing.
LB(2/6): Bryan Kehl-Sunday, week 6, playing Dallas.
Desmond Bishop- Sunday, week 6, playing Carolina after a bye week.
OL(3/5): Maurkice Pouncey- Sunday, week 1, playing Tennessee.
Garry Williams- Sunday, week 1, playing Seattle.
Amini Silatolu- Sunday, week 5, playing Arizona after a bye week.
WR(2/10): Charles Johnson- in practice, week 6ish.
Reggie Wayne- Sunday, week 7, playing Denver after Monday night game.
RB(3/3): LaRod Stephens-Howling- Sunday, week 1, playing Tennessee.
Vick Ballard- Practice, before week 2.
Mike Goodson- Sunday, week 6, playing Pittsburgh.
DT(3/3): Henry Melton- Sunday, week 3, playing Pittsburgh.
Nate Collins- Sunday, week 5, playing New Orleans.
Geno Atkins- Thursday, week 9, playing Miami.
QB(2/2): Brian Hoyer- Thursday, week 5, playing Buffalo.
Sam Bradford- Sunday, week 7, playing Carolina.
Interesting Notes
There have been a total of 103 games played on Sunday so far this year. There have been 13 ACL tears on those games, meaning there has been a tear in 12.6% of Sunday games.
There have been a total of 9 Thursday night games played this year. There have been 2 ACL tears in those games, meaning there has been a tear in 22.2% of Thursday games.
QBs, DTs, and RBs all exclusively got injuries in the regular season. Almost every other position was hit hardest in the offseason.
Pittsburgh, Tennessee, and Carolina have each played in two games where someone on the opposing team tore an ACL. Carolina has 3 ACL injuries themselves, and Pittsburgh has 2.
No ACL tear has happened on MNF. Reggie Wayne tore his the week following a MNF game. EDIT: Sidney Rice tore his ACL on MNF in Week 8 against the Rams. Thank you /u/folieadeux6.
While there have only been two Thursday night injuries, arguably the two most significant losses to their respective teams happened on Thursday night. Hoyer the Destroyer and Geno Atkins were the staples of the Browns offense and Bengals defense.
Final Thoughts
The offseason is really what stands out. I won't speculate as to why it's so overwhelmingly represented on this list, but I know many of you have pointed out the restriction of offseason practices and conditioning may contribute.
While it may look like the 10% difference between Thursday night games and Sunday games is significant, its not enough to start and outcry and bust out the pitchforks. The sample size is way too small. Part of the reason the Thursday night injuries stand out so much is because of the significance of the injuries to each team. Maybe the AFC North should just boycott Thursday night games.
Thanks for reading. If anyone wants to expand on this feel free. This is pretty bare bones, so any additional statistical analysis is welcome.
EDIT: /u/InheritTheWind has compiled a more up to date list of ACL injuries. There have actually been 45 total injuries. His thread where he is keeping an updated count of the injuries can be found here.
