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 to having little dependencies on piece orders.
Variant 1 SDT
The L piece can be tucked in after Z or ZO are placed in games with 180° rotation. This variant requires LZ before O.
97.22% PC Chance
There are 8 minimal solutions:
3rd bag T-Spin Triple route:
You will always be able to build this as the order of OSZ does not matter.
With the right piece order, you can delay the 2nd bag T-Spin and complete the BT cannon.
4th bag T-Spin Double route:
There is a 80.24% chance to achieve a perfect clear after 14 lines with 2 minimals:
The first solution may result in a T-Spin Single beforehand.
An alternate 4th bag TSD setup discovered by Nakamuraa which only needs J before S:
There is a 85.24% chance to achieve a perfect clear after 14 lines with 3 minimals:
The 2nd solution can lead to a Tetris perfect clear.
Variant 2 SDT
This variant requires OL before Z.
97.34% PC chance
There are 10 minimal solutions and they are shown below. All except the last two solutions cover at least 20% of all bags.
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 can 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.
All minimal solutions are shown. Each one can be stacked using at least 25% of all bags.
Variant 3 SDT
This variant requires O before I and LZ before S. Note that you can insert the O piece after the J piece is placed and tuck in the I piece after O and J pieces are placed. Additionally, the L piece can also be spun in after Z and S pieces are placed with the help of 180°spin. There is a 96.98% PC chance, providing both Tetris and TSD/TSS solutions and >60% chance to save O. It is quite rare compared to the 2 ways of building above but is very potent. Hold S when you can for 100% PC chance, refer to Hold 1 piece section for more details.
96.98% PC chance
There are 8 solutions:
3rd bag T-Spin Triple route, L before O:
With the right piece order, you can delay the 2nd bag T-Spin and complete the BT cannon.
4th bag T-Spin Double route, J before Z,I:
There is a 81.67% chance to achieve a perfect clear after 14 lines with 7 minimals, the 2nd solution may lead to a tetris PC: Link - >[1]
Some ways to continue t-spinning afterwards: Link - >[2]
4th bag TSD, 100%:
Some ways to continue TSD: Link ->[3]
3rd bag TSD, O before L:
You can delay the 2nd bag TSD to complete the TSD with the right piece order, in the same fashion with main route and L before O.
You can switch to main route TSD on 4th bag if I piece can be placed before S piece, do note that aiming this can be very risky and you will likely need to waste T if it fails:
Variant 4 Cut-copy
This variant requires OZ before L. This creates a jaws-shaped cut-copy that can be continued with a perfect clear. When there is no perfect clear, you can tuck the Z piece under the overhang to the right to freestyle a STSD/Trinity.
69.33% PC chance
Below are solutions with potential T-spin double:
Full list of minimal solution here: Link - >[4]
If you can hold the L piece, the perfect clear success rates are increased and you are also allowed more freedom of continuations such as a Fractal on the next bag.
87.22% PC chance
Below are examples of solutions with >33% chance of happening.
Solutions for hold L: Link - >[5]
Variant 5 T-Spin Double
This variant requires early L and will most likely cover what the other variants does not. While it does not offer an 8 line perfect clear, the shape is clean and allows a lot of freestyling for 6-3 stacking. In the next bag, you can simply put a S piece down for a T-spin double and start a 6-3 stack.
Variant 6 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 abort the second T-spin double and do a T-spin single and skim/downstack.
Variant 7 Hold 1 Piece
Here are some patterns that are even more focused on Perfect Clears. These setups all have 100% or extremely close to 100% PC chance, depending on what your held piece is. Note that this pattern is geared towards people who are already experienced with solving variant 1 or 2 PCs and/or relatively good at spotting PCs. Please also mind that sometimes the TSD can already be done with even fewer pieces placed such as a minimum of OJI in hold Z and IJLZ/OJLZ in other patterns.
Hold I, 100% PC chance
Solutions here: Link - >[6]
You can also always perform an alternate placement of main route SDT by holding I:
Hold Z, 100% PC chance
As shown in variant 2's subsection, you do not have to hold the Z here to have 100% PC chance but it does give you more options to solve the PC with.
This setup has 5 minimals.
Hold S, 100% PC chance
This setup has 4 minimals.
Below is an example of Tspin solution exclusive to holding S, you can also clear the double using the S without thinking but still have 100% PC chance with potential tspin solutions while giving up Tetris pc chance, there is still at least around 70% chance to save O by doing so:
Solutions here: Link - >[7]
Hold O, 99.37% PC chance
This setup has 8 minimals.
Miscellaneous
2 Line PC
You will have a small chance to do a 2 height perfect clear if not more than 1 piece among TSZ comes before all of ILOJ after performing a 8 height PC with O piece as the remaining piece like in this case:
You can follow this up with what is known as a TSZ 7th PC. There are a few forms but we will take the simplest ones here:
Above are a few examples of how to solve this setup and they're very simple and straightforward.
If you successfully get the perfect clear you will be returned to a fresh bag unless you used a piece from the next bag to solve.
In that case you will be led to what that is a 8th PC. (1st PC but with 1 duplicate piece and 1 missing piece)
For example, we will have 2 I pieces and no S pieces in the next bag if we solve it this way:
After 4th bag TSD in Variant 1
We can always build a TSD easily like the TSS solution and take the TSD. In some cases we can have a perfect clear after the TSD by using the first piece from next bag which will result in the same scenario as explained above.
ISZ are the key pieces and you can stack the rest as you like but with ISZO placed you can still Perfect Clear after TSD instead of TSS in some cases with this form if I piece is the first piece in next bag. Depending on your board state, you can quickly follow up after the TSD with a Tetris or Tetris PC.
Please note that these PCs are really rare cases.
