ever wondered what the mythical "supertest" is and how many players are there testing vehicles?
Supertest is an assembly of regular players (not experts or professional) testing various WoT elements internally for Wargaming. In theory they are all under non-disclosure agreement but from the previous posts you can see how well that is working. Supertest is exclusively RU-server. There used to be an European supertest but it was closed two years ago after series of leaks.
The following post (leaked from supertest internal forums) shows the numbers and distribution of winrate amongst the supertesters. There are apparently 629 supertesters in total with such winrates (Marokko is supertester leader):