Which 2001 Tetris game introduced the Super Rotation System?

The 2001 Tetris game that introduced the Super Rotation System was Tetris Worlds.

Released in 2001, Tetris Worlds used the Super Rotation System, commonly abbreviated SRS, to define how tetrominoes rotate. SRS specifies the rotation states of pieces and the wall-kick tests used when a rotation would otherwise collide with the playfield or stacked blocks.

That technical framework helped make modern Tetris movement more predictable. Players could learn consistent rotation patterns and use wall kicks to maneuver pieces into tight spaces. Tetris Worlds also introduced or popularized other guideline-era mechanics, including infinite spin, in which repeated rotations could delay a piece’s descent.

The answer is sometimes confused with The New Tetris, which is associated with the hold feature, and with later games such as Tetris DS. SRS is not a scoring technique like a T-spin; it is the underlying rotation rule set that determines how pieces turn and reposition.