You're referring to the chess courses by Grandmaster Igor Smirnov!
Calculation is the engine of chess. Smirnov teaches a disciplined method for calculating variations without getting lost in the "trees" of the position. Tactical vision and calculation accuracy. gm igor smirnov all 9 chess courses new
A dedicated course for improving calculation and visualization speed. You're referring to the chess courses by Grandmaster
: A psychological and tactical guide on handling higher-rated players. Pawn structure and mobility Piece placement and coordination