ChessCalisthenics is a training system of structured repetitive exercises that involve no resistance.  For our purposes, resistance refers to the effort you may have to exert in solving a chess problem.   Our training system encourages you to start by simply replaying combinations with similar patterns.   We provide the chess positions and you replay them.  In time, because of the visualization skills you acquire, you will naturally start to analyze positions more and more deeply.  Eventually, you will develop the ability of conducting a quick and sharp analysis when presented with a chess position.  Potential three and four move combinations will jump out at you as being obvious.