From Hard Drop Tetris Wiki
Setspin is a 1st bag TSS opener created by 10Penta. Its main continuation is a TST Tower, which can always be executed on the 3rd and 4th bags, unlike most other TST Tower openers. There are also Incomplete TST and LST continuations.



First Bag
The first bag has a 63.3% chance to stack the first bag including the mirror, and a 43.3% chance not including mirrors.

TST Tower Continuation
There are 2 setups that cover the 2nd bag with LJO interchangeable:
Z<T 
T<Z 
You may need to use hold.
Route 1 Z<T
The first image can always be built, but the second and third may result in a flatter stack:



10Line PC Chance
If you can stack like below, you have a chance for a 10Line PC:


You now have a 12.62% chance to PC with 4 minimals, with a 7.6% chance for a TST solve:




Route 2 T<Z
There are 3 good ways to stack bag 4. The last one is messy so avoid it if possible, but it may be required.




CSpin Followup
After most TST tower setups, it is possible to build a Cspin followup. Below is an example after the flat Z<T setup:

Incomplete TST Continuations
The following continuations, created by 10Penta, build an incomplete TST followed by an Imperial Cross, TST or TSD into 14L PC.
Route 1 O<Z
L and J are interchangeable. There are many good ways to build an Imperial Cross on the 3rd bag, the setup below covers all bags with the JLS interchangeable:




10Line PC Chance
If you have I<S, then you can stack as below for a chance for a 10Line PC:


You now have a 67.6% chance to PC with T on hold with 29 minimals.
Route 2 Z<O, J<L
On the 3rd bag, we can make a TST with 2 setups (first one may require gravity):


O<L 
L<O 
If you can hold I until after the TST, you can spin it under the overhang to create a better stack. Below is an example for O<L:



Alternatively, you can perform an 100% TSD > TST made by seacucumber (OLJ interchangeable); There are many ways to build the TST, the two setups below cover all bags.


O<J 
J<O 
Route 3 Z<O, L<J


There are TST continuations here, but most of them are messy, so freestyle is possible or the TSD 14L below:




You now have a 99.46% chance to PC with T on hold with 12 minimals.
Alternatively, on the 4th bag, you can setup this STSD with OSZ interchangeable (by winterfrost):

LST Continuaton
This LST Continuation, discovered by ADT, requires L<S:


Full Document
There are some less important details, setups and PC solutions that have not been included in this wiki page, but are on the full opener document which can be accessed here.