Overview of Second PC
To solve 1st PC, you must take 3 pieces out of the 2nd bag. There will then be four leftover pieces, which are usually used in the setup. Since you use six out of the seven pieces out of the new bag to solve 2nd PC, the unused piece is referred to as the "saved piece," and will be the 3rd PC/DPC you go to. Usually, good setups will depend on whether you are DPC looping (O > SZ > I > JL > T) or doing pure PC (T > O > I > JL > SZ). This page is designed for pure PC.
If a setup has an exclamation mark after it (!), that means it cannot always be built with any queue. Usually, there will be a different setup that can be built instead, but again, no guarantees are given.
How this article is organized
Each four-piece queue can make multiple setups, and each setup can cover multiple queues. This page shows useful setups that usually cover multiple queues in order to be as efficient as possible. Some queues may not be covered, and other, more specific setups might be needed. These setups may not be exactly the best setups for specific queues, as some compromises are made in order to make sure this page is not too long.
With a T piece
Tub
Tub is a very reliable 100% 2nd PC setup that can save O almost always. The solves are very simple, just fill in the "tub" shape with ST or ZT and fill the 4x4 box with IJLZ or IJLS, respectively. Sometimes you are forced to box with IJLO which saves S, and should be avoided at all costs(although, you are forced to save S or Z 1.35% of the time).
(TIP: try and make the 3x4 JLS/JLZ box stand up if you can, as then you can get a Tetris PC!)
IJST/ILZT, ILST/IJZT!, JSZT/LSZT, IJLT
Solutions:
Note: These solutions are not comprehensive, and are just to give you an idea of what to aim for.
PCO + Heart
So called because it has the Perfect clear shape and the Heart shape, this setup, while sometimes hard to solve, has good saves.
ILOT/IJOT, ILZT/IJST, JOZT/LOST, LOZT/JOST!
Solutions:
Knoll
A weird setup with an even weirder name, however it's a good setup with good saves.
99.72%
OSZT, IOZT/IOST, JLTZ/JLTS, IJLT
Solutions:
ISZT pattern
This is a queue-specific pattern, only used for ISTZ. Only the first and last solutions are needed to achieve 100% PC rate, but the other two solutions will maximise the chance to save T, and minimise the chance to save S or Z.
Solutions:
Both J and L
3x4 box + O
JLZO/JLSO
Solutions:
Note: ABSOLUTELY NOT NECESSARY to learn all 18 minimals. While this article lists all minimals, they do not have good saves. 3x4 + O is a very advanced setups, and is very hard to learn. However, keep practicing, and you will become a Perfect Clear God!
Second note: Flipping the box on it's side makes it a lot easier to solve, however it is a lot worse for third pc.
4x4 Box
IJLO, IJLZ/IJLZ
Solutions:
6x4 solutions are many and numerous, and listing the solves would be a sisyphean task. Despite being a good perfect clear setup, the only good way to learn is to struggle through each solution one by one.
JLSZ
Solutions:
After the boxes, the solutions are easy enough.
No T, uneven J and L pieces
Here is where you will see the perfect clear chance dropping very, very quickly.
80% chance, oh my
Easy setup, 3 minimals, if only it wasn't 80%...
JOSZ/LOSZ, IJSZ/ILSZ, ILOS/IJOS
Solutions: