USA: Play as fast as possible. It seems its country illegal to use the full time - for example 10 minutes - of a game. Strong in opening, bad in endgame.

India: Bad in opening and get stronger the more pieces are captured. (Endgame monsters)

Russia: Like India, but opening theorie focused and endgame monsters. Think at move one strategic.

Germany: Like USA, but opening is allways theorie.

Brazil: The warlocks in chess. In midgame, they use their most time, then find moves, nobody can see - maybe Stockfish? Their practice of chess is obviously very different from rest of the world and I stopped played against them, because it looks everyone is cheating - even if it doesnt apply. (500 games versus brazil only 2 victorys in same ranking) No thank you.

Indosia, Egypt, Iran, etc: Usually playing fast, everyone has different strenghts in game phases.

Beside that stuff, chesscom is FULL of CHEATERS and TROLLS. Fair matchmaking? Of course NOT. Chesscom do nearly nothing to bann those guys.

Gadakar86