Main Article: ST Stacking
Base
Two Columns Wide
Two columns wide bases do not have the modular flexibility of three columns wide bases. They, however, provide more room to stack the field. The simplicity of required tetrominos in the setups also makes them easy to learn.
Three Columns Wide
Unlike the two columns method, three columns wide bases have the advantage of modular cores. A player can opt for a different core to accomodate an unfavorable preview. Although the player has less room to stack the field, tetromino dependence is minimized. I tetrominos are also not needed to fill in leftover gaps.
Alternatives
ST L Start
For two column wide ST bases, an L start may be desired if an L comes early in preview order. An L start will also fill in the first leftover gap created by the S tetromino. Note that the notch for the L start is one row lower than that of an S start.
After performing four T-Spin Doubles using an ST base and plugging the leftover gap with an I, a player can use the L Start base in place of an S base. Note that the notch for the L base is one row lower than that of an S base.
ST JL Alternative
For two column wide ST bases, a player often waits for three or more T-Spin Doubles before filling in the leftover gap with an I tetromino. A player may opt to use a J to fill in the leftover gap formed after two successive T-Spin Doubles. Identical to the ST L Start, an L will be used as the base for the next T-Spin Double, after which regular ST base stacking may resume. This method can be used repeatedly to eliminate the need of using an I tetromino to fill in the leftover gaps normally created from only using S tetrominos.
Notch
Type 1
Type 1 notches can be used as openers for ST bases and for three column wide bases because they are three rows high. Type 1 notches require only two tetrominos to complete and are interchangeable with one another.
Type 2
Type 2 notches cannot be used as an opener because they are only one row high. Type 2 notches require only two tetrominos to complete and are interchangeable with one another.
Not Recommended
This notch is not recommended because it requires the usage of the T tetromino, of which can be used for the T-Spin Double. This setup can be stacked on top of other type 2 notch setups but the opposite cannot be done because of the overlapping T tetromino obstruction. This setup should only be used for emergency cases because it will also force the usage of two Z tetrominoes to create the next notch.
Type 2 openings
Practical openings for type 2 include the following.
Type 3
Type 3 notches resemble Back-To-Back T-Spin Triple Setups. They can be used as openers for LT, SLT, and L Start bases because they are two rows high. Type 3 notches require three tetrominoes to complete the first notch and four to complete the setup, with the exception of TJ and LT. Type 3 setups are interchangeable with one another only after the full setup is complete and are the least recommended of the notch types because they require too many tetrominoes.
Not Recommended
This setups require only two tetrominoes to complete. These notch setups are not recommended because they require the usage of the T tetromino, of which can be used for the T-Spin Double. This setup can be stacked on top of other type 3 notch setups.
Notch Type Converter
Type 1 -> 2
Type 1 -> 3
Type 2 -> 1
Type 2 -> 3
Type 3 -> 1
Type 3 -> 2
Situational
Notch
