Nintendo Rotation System

Right-handed version was used in Tetris (NES, Nintendo) and Tetris & Dr. Mario. Tetrominoes spawn with their highest block on row 20.

Left-handed version was used in Tetris (Game Boy). Tetrominoes enter with their highest block on row 17.

Games using this rotation system generally have no wall kick and no lock delay.

Later Tetris games published by Nintendo (Tetris DX, The New Tetris, and Tetris DS) use different rotation systems.