Last is an opener with a series of TSS→ TSD→Perfect Clear patterns by Eternalaws. You will need a L before S to execute the T-spin single in the first bag(J before Z when mirrored). This opener can frequently be done due having little dependencies on piece orders.
Variant 1 SDT
The L piece can be tucked in after Z or Z and O pieces are placed in a game with 180°rotation. This variant requires LZ before O.
97.22% PC chance
There are 8minimal solutions:
3rd bag T-spin triple route:
With the right piece order, you can delay the 2nd bag tspin and complete the BT cannon.
4th bag:
There is a 80.24% chance to achieve a perfect clear after 14lines with 2 patterns:
The first solution may result in a T-spin single beforehand.
Variant 2 SDT
This variant requires relatively OL before Z.
97.34% PC chance
There are 18minimal solutions, below are solutions with >25% chance of happening:
Full list of minimal solution here: Link - >[1]
3rd bag T-spin triple route, it is not recommended to build a T-spin triple when you cannot place down O before S:
Like the first variant, you may delay the 2nd bag T-spin double to complete the bt cannon when you have a late T on 3rd bag.
4th bag T-spin double route:
100% PC chance
There is an alternate way of stacking the 2nd bag which gives a 100% chance for perfect clear in 3rd bag, note that the T-spin double can be done as soon as I,J and O pieces are placed down so you can actively lookout for such a queue.
Variant 3 Cut-copy
This is for when you need to place down the Z piece after O piece is placed, usually a jaws-looking cut-copy is made. When there is no perfect clear you can place the Z pieve to the right to freestyle a STSD/Trinity. This variant requires OZ before L.
69.33% PC chance
Below are solutions with potential T-spin double:
Full list of minimal solution here: Link - >[2]
If you can hold the L piece, the chance to perfect clear is raised and you are allowed more freedom of continuations such as a fractral on the next bag.
87.22% PC chance
Below are examples of solutions with >33%chance of happening.
Solutions for hold L: Link - >[3]
Variant 4 T-spin double
This variant requires early L and will most likely cover what the other variants does not. While it does not offer a perfect clear at 8th line, the shape is clean and allows a lot of freestyling from 6-3stacking. In the next bag, you can simply put a S piece down for a T-spin double and start a 6-3 stack.
Variant 5 T-spin Fin
With an early Z, you may also build a T-spin Fin to 2 T-spin double setup like this:
Note that the J piece can be spun in after other pieces are placed, the second pattern will likely result in a bad board state if both L and I pieces are late next bag. You may need to abord the second T-spin double and do a T-spin single and skim/downstack combo.
