Question 1

What is a Tetris?

Accepted Answer

A Tetris is clearing four lines at once with a straight I-piece.

Question 2

When should I use hold?

Accepted Answer

Use hold to save key pieces for planned clears or to avoid dangerous placements.

Question 3

Is clearing singles bad?

Accepted Answer

Not always. Singles can stabilize a messy board and prevent top-outs.