Team Performance Affected By Certain Constructions

[Cat Harrison]

Building has no affect on performance. Upgrading grass does lower injuries, a bit. But other than that there is zero affect on your players from building/upgrading.
Just a coincidence.

Teams can go through periods where they are not performing well, but the facilities won't change that..

[Tactician]

Building has no affect on performance. Upgrading grass does lower injuries, a bit. But other than that there is zero affect on your players from building/upgrading.
Just a coincidence.

Teams can go through periods where they are not performing well, but the facilities won't change that..

What is the duration and frequency of these so called unexplained bad periods?