TETRIS GLOSSARY
Parity
Also called Checkerboard parity · Column parity
A way to reason about even/odd balance in a stack or empty region. Checkerboard coloring helps test tiling possibilities; column-height parity helps explain awkward surfaces. Passing a parity check alone does not prove a solution exists.
View in the A–Z glossary →O · 2 LIGHT + 2 DARK
T · 3 + 1
Dots retain the underlying checkerboard colors. Counting them can rule out some tilings; equal totals alone do not guarantee a solution.