Cut copy

Cut copy (formerly Kiritori Kopi) is an 'investing' technique where you save the T shape underneath the T-Spin. Translated into English, the term means Cut Copy. The setup is also called 千鳥格子/Chidori Goushi, meaning "A Thousand Birds Grid", which shape looks like this Japanese art.

Generic Structures
Cut Copy has two types of generic structures. Both types are considered Cut copy because both of them consist of a T-Spin "cut" by another T-Spin.

The first type of Cut copy is the one where only the bottom-half of the second T-Spin Double is saved underneath. Many player considered this type as the "true" Cut copy.


 * fumen #1

The second type of Cut copy is the one where the whole second T-Spin Double is saved underneath. It could be easily mistaken with STMB Cave.


 * fumen #2

Variations, Other Uses and Comparisons

 * Cut copy could be made using pieces other than the generic structure and still maintains the same function as long as the structure is similar to those.

fumen #3


 * This variation of Cut copy requires a deeper hole and involves a line clear, but uses S and Z rather than 2 Zs.


 * Repeating the second type of Cut copy is possible although it is adequately hard to detect the opportunity of doing so.


 * Even though it is very difficult to see the favorable occasion of making this, it is possible to mix both types of Cut copy to make three consecutive T-Spin Doubles.


 * Using Cut copy along with Donation could help getting an efficient pieces usage.


 * It is possible to make a Cut copy underneath an STSD.