Gamushiro Stacking

Gamushiro Stacking (ガムシロ積み) is a T-Spin opener created by Mr. Goods. It is a Triple Double Attack opener. In the first bag, only the J piece is required before the S. If the mirrored setup is considered, it is always possible to stack the first bag. After the T-Spin Triple from the second bag, it may lead to a Perfect Clear opportunity or other continuations.

First Bag setup
You only need the J piece before S (L before Z in the mirrored setup). The L piece is kept on hold as it will be used along with the second bag.

Here is the first bag with all 7 pieces:

Second Bag
The second bag is always placed in one of these ways. The first 2 ways are the most desirable ways. The first 4 ways can result in a Perfect Clear.

Third Bag (Perfect Clear)
In the case of the first 4 forms mentioned, you can get a Perfect Clear after 8 total lines.


 * L → O (99.09% PC rate, 22 minimal solutions)


 * J → O (96.94% PC rate, 19 minimal solutions)


 * S → O (86.59% PC rate, 15 minimal solutions)

Form A1 and A2 (L → O)

 * T-Spin Triple


 * Imperial Cross


 * Center 4-wide

Form B (J → O)

 * Nil-cross


 * Trinity

Form D (O → L)

 * T-Spin Triple: In the third bag, the O piece must come before Z and S before J.


 * Double Triple Cannon: In the third bag, the J piece must come before S and Z before O. In the fourth bag, you can mostly stack the below. It will fail if you get J before T, S and O. It also requires a late T.


 * Double Triple Cannon 2: The third and fourth bags are stacked the same way, except that the T piece comes early in the fourth bag. Unlike the DT Cannon continuation, you can always stack the fourth bag, as long as you get the T piece early.

Perfect Clear after 10 or 14 lines

 * 10-line Perfect Clear (63.73% PC rate, 22 minimal solutions): You can use this continuation from Form A or C. There are quite some dependencies in the third bag, namely S before J, O before Z then I, or in the case of Form C, O and Z before L and I.


 * 14-line Perfect Clear (100.00% PC rate, 10 minimal solutions): In the fourth bag, only S must come before Z. The I, J, L and O pieces can be placed in any order. The solutions are the same as Riviclia's Pelican.

3rd bag
The firepower will be lower, but it can always be stacked instead. perform TSS.

4th bag
Always Tetris.

5th bag(PC)
PC rate is 100.00%, TetrisPC rate is 76.67%, 2 filter solutions.

2nd bag
The placement of the L-piece is distinctive. This allows for a 14-lines PC.

3rd bag
Always TSS.

4th bag
Always TSD. Z-piece, J-piece, and L-piece are interchangeable in placement. Hold the S-piece.

5th bag(PC)
PC rate is 100.00%, 7 filter solutions.