The injury database from which we calcluate our return to play data is derived from publically available injury information from the NFL, NBA, NHL, and MLB and includes over 50,000 injuries. We consider the time at which the player was injured to the time the player again plays in a regular season game to be the return to play time. If a player does not return to play in a given season the injury is considered season ending. Our goal is to provide a cursory estimate for return to play based on type of injury. In reality every athlete and every injury is unique - we are simply presenting the averages.

"Average return to play" is presented in days. For all injuries, we calculate both a median and a mean return to play time. In general, the median and mean are roughly equivalent. However, in some cases, the mean greatly exceeds the median, usually due to an extreme outlier. Thus, the reported "average" is typically the mean return to play time, but in cases where the mean exceeded the median by more than 30%, likely due to an outlier, the median is reported.

"Percent season ending" is calculated as the total number of injuries of a certain type that resulted in the player not returning that season divided by the total number of injuries of that type.

There are significant limitations in the data we collect and therefore the return to play times we present. We are bound to the accuracy of reported information. Injuries are often reported with minimal specificity; for instance, an athlete might suffer a femur fracture, but it's simply reported as a "thigh injury." While expansive, we do not claim to be comprehensive. Some injuries are rare, or rarely recorded, resulting in an average that may be based on a small sample size. Finally, our database is not updated on a regular basis. The current version includes injuries through 2016. We hope to gain resources in the future that will allow us to update regularly.

Our ability to collect injury data would not be possible without the players, teams, staffs, and reporters involved in reporting athletic injuries to the public in addition to the incredible work of websites that work to consolidate this information such as and . We highly recommend visiting these websites.

For more information, feel free to contact us directly.