9–0 stacking

Related terms

• Well →

  An intentionally open vertical channel for clearing lines, often with an I. Keep its entry accessible. Some older writing also uses well to mean the entire playfield.

• Tetris →

  Four rows cleared by one placement, normally using a vertical I. The name also refers to the game itself. A Tetris can leave many blocks behind, while a Perfect Clear leaves none.

• Dependency →

  A shape that strongly needs one particular piece. A deep one-column gap needs an I; several such demands at once make the stack inflexible. Prefer placements that leave multiple useful options.