Linux

Is gaming stat based on steam survey? If so that shows wild variation, and also has a flawed metric collection. From a steam article they measure your game play of a title during the first 2 weeks of purchase, so if you dualboort and play more time on Windows for that period, that is the stat, negating if you then played months or years on Linux after it.

Statcounter has an other category, and when Linux drops or raises % there is a symmetrically opposite change in the Other %. To me this Other probably includes the machines you mention.