Number One

Number One is a single bag opener discovered by player Riviclia that results in a platform T-Spin Double. Thereby, the first T piece is spun into a vertical position like in STSD which makes it different from most other platform openers. It has quite some dependencies in the first bag (L after O, Z after S, J after I) but despite of its look it is a really good opener if applicable.

After the T-Spin Double
There is a single floating mino in row 2 located on the right side. However, with SRS spins it is possible to fill the area beneath it, and prepare a T-Spin Double as if the setup was just a regular STSD. Note that in diagram 3 J piece must be spun 2 times to reach the desired location.



Some advanced techniques:

6-line PC
If one can stack the right side like in the leftmost diagram, there may be a chance for a Perfect Clear after 6 lines. Sometimes, one does a TSS before the PC. There is no way to get a PC with a TSD. First invented by MalaiABUeditor.

If one gets an early I in their third bag, the below stack may work, but has several piece dependencies, so the above is better.

TST TSD Perfect Clear
The first continuation looks like a T-Spin Triple setup but with an empty cell in row 2. So it just results in a T-Spin Double and the empty cell can be used to prepare another T-Spin. This continuation can be reached by spinning the J piece beneath the floating mino whereas there are 2 different paths; one where J is placed horizontally (diagram 3) and one where J is placed vertically (diagram 2).




 * Path 1: 98.17%




 * Path 2: 90.4%



If one decides not to make a Perfect Clear, they can convert the remains to a T-Spin Triple or Imperial Cross.

Imperial Cross Perfect Clear
The second continuation involves building an Imperial Cross with the remains of the STSD. There are 2 different paths again; one involving an L-Spin (diagram 3) and the other involving a Z-Spin (diagram 2).




 * Path 3: 80.48%




 * Path 4: 80.28%



Again, if one decides not to make a Perfect Clear, they can convert the incomplete TSD to a T-Spin Triple or Imperial Cross.

After 14 lines
When it comes to 14 lines, there is no definite way. Below is an example, with three Imperial Crosses.