TETRIS GLOSSARY
Bag boundary
Also called Bag seam · Bag transition
The join between two shuffled bags. Consecutive matching pieces can occur here. Tracking the boundary tells you which pieces remain guaranteed in the current seven-piece set.
View in the A–Z glossary →END OF BAG 1
LTI
START OF BAG 2
IOZ
An I can end one bag and begin the next. A repeated piece across the boundary is valid.