PC-Spin is a Triple Double opener that starts with a T-Spin Triple which is then followed by either a T-Spin Double or a T-Spin Single and ends with a Perfect Clear after six or eight lines. It was invented by Hard Drop member Aitch and the name originates from a portmanteau between PC, the abbreviation for Perfect Clear, and C-Spin, a Triple Double technique. This opener was made as a reliable setup for a Perfect Clear after a few cleared lines. What is unique is that there are two different setups which were both named PC-Spin. One is for a Perfect Clear after six lines, and the other is for a Perfect Clear after eight lines.
"I use the first when I just want a C-Spin with a chance for PC, and I use the second when I want C-Spin PC."
— Aitch
6-line Perfect Clear opener
If you are targeting to achieve a Perfect Clear after six lines after a T-Spin Triple, this version should be used. After the T-Spin Triple, a T-Spin Single may be scored along with the Perfect Clear, otherwise it would simply be a single line clear. In total, it should require three bags, if not more.
First bag
In the first bag, this opener requires an early I, O and J pieces (specifically I before L then S, O before Z, and J before T). Like the creator who stated "A big downside is the first bag is not very likely.", this is likely to be one of the openers that is the most piece dependent in the first bag.
The overall setup rate, with Hold and softdrops allowed and also its mirrored setup, is 30.95%, or if only the left setup below, the rate would be 22.70%.
Second bag
In the second bag, ideally, if the O piece can be kept on hold until the T-Spin Triple is attained, there may be a chance to achieve a Perfect Clear. You have a 33.33% chance to stack the ideal way.
If you must place the O piece before the T-Spin Triple, one of the first two ways will always be applicable along with the J piece. If you want to have a chance to achieve a Perfect Clear in the third bag, choose one of the final two ways, both of which would result in the same shape.
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O → J
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J → O
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8 lines PC
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8 lines PC
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Third bag
Perfect Clear
- Setup A (33.33% setup rate, 19.05% PC rate, 3 solutions): There is a slight chance that a Perfect Clear could be achieved followed after a T-Spin Single, given the three solutions shown below.
T-Spin Triple / Imperial Cross
If it is impossible to achieve a Perfect Clear, one can make another T-Spin Triple or Imperial Cross in the third bag. In the case of the former, the second bag's O piece is used to convert the T-Spin Single to a T-Spin Triple and add an overhang from the third bag. For the latter, use the third bag's S piece (the second bag's O would be used somewhere else).
8-line Perfect Clear opener
If you are aiming to achieve a Perfect Clear after eight lines instead that may include a T-Spin Double or Single as a bonus, this version should be used. In total, it should use three bags, if achieving a Perfect Clear is attainable.
First bag
In the first bag, the J piece must come before S, and L piece before O and I.
The overall setup rate, with Hold and softdrops allowed and also its mirrored setup, is 73.33%, or if only the left setup below, the rate would be 56.67%.
Second bag
In total, there are four setups (or six if the cases that I piece was placed on J or L in the final master setup were considered distinct) that will cover the following second bag cases.
- Setup A - S → JO and I → L (32.22% setup rate, 96.94% PC rate)
- Setup B - S → OL and I → J (32.22% setup rate, 95.12% PC rate)
- Setup C - O → S (75% setup rate, 93.85% PC rate)
- Setup D - S → O and L → I or J → I (54.44% setup rate, 70.95% PC rate): If the I piece is on hold, there will be an 81.71% PC rate in the third bag.
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70.95%
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70.95%
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80.71% (I on hold)
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Third bag Perfect Clear
- Setup D1 (70.95% PC rate, 3 minimal solutions): For the solutions they will be shown with the second bag's I piece on the L piece. The solutions are the same when it is on the J piece.
Okey Version
- Main Article: PC-Spin (Okey Version)
This variation of the 8th Row Perfect Clear Setup was proposed by the player Okey_Dokey. It results in fewer case differentiations in the second bag, as well as better Perfect Clear chances in the third bag. The first bag is stacked in exactly the same way as in the standard version - except for the I piece which is placed vertically one column away from the left wall. In the second bag the player must pay attention to the order in which the O and J pieces show up. Like in the standard version, a T-Spin Triple is executed at the end of the second bag which also prepares a T-Spin Single for the third bag.
If O comes before J, then the second bag can always be stacked like this (this is the preferred way):
And if J comes before O, then the second bag can always be stacked like this (it may require a J-Spin if J comes after S and T):
The case O before J offers a 95.9 % chance to get a PC in the third bag, or 71.2 % if requiring a T-Spin Single beforehand (and 48.7 % if requiring a TSD).
The 71.2 % chance for TSS -> PC can be achieved by using these 14 PC solutions (all solutions):
If the T piece shows up among the first two pieces of the third bag, then it is always possible to achieve a PC after starting the bag with a T-Spin Single.
The 95.9 % chance for just PC can be achieved by using these four PC solutions additionally (all solutions):
The case J before O offers a 96.9 % chance to get a PC in the third bag, or 65.1 % if requiring a T-Spin Single beforehand (and 39.0 % if requiring a TSD).
The 65.1 % chance for TSS -> PC can be achieved by using these 11 PC solutions (all solutions):
Note that here the T-Spin is sometimes required to be vertical, in which case either J piece or L will stay on hold instead of S, Z, O or I.
The 96.9 % for just PC can be achieved by using these nine PC solutions additionally (all solutions):
See also
External links
- Post made by Aitch regarding his setups
