Gamushiro Stacking

Gamushiro Stacking (ガムシロ積み) is a T-Spin Opener first created by Mr. Goods. It opens with a Triple Double Attack. In the first bag, J and O should come early. After a T-Spin Triple from the second bag is performed, it may lead to a Perfect Clear opportunity (99%) or other continuations. Sometimes, one will do a TSS or TSD before the PC. If one considers the mirrored version, it is always possible to stack this opener as long as O comes early.

Second Bag
In the second bag, one can stack it in one of four ways. The first way is the most preferred. In all cases, the Z piece can be placed in even though the S might be there already.

Third Bag
There are various continuations for the third bag.

Perfect Clear
This is usually the best continuation. In some cases a T-Spin Single or a T-Spin Double may be done beforehand. If one gets an early T in the third bag, they may do a TSS immediately.


 * Form 1 - 71 solutions, 99.09% PC Chance


 * Form 2 - 27 solutions, 72.82% PC Chance (these solutions also apply to one of the setups in PC-Spin)


 * Form 3 - 24 solutions, 49.37% PC Chance

Other continuations

 * T-Spin Triple


 * Imperial Cross


 * Center 4-wide


 * Nil-cross


 * Trinity

Perfect Clear after 10 or 14 lines
In this case, one can go for a Perfect Clear after 10 lines or 14 lines. There are some dependencies in the third bag: S before J, O before Z then I. At that point, one will have a chance to make a Perfect Clear after 10 lines. If this fails, then 14 lines is always possible, provided that S comes before Z in the fourth bag. The I, J, L and O pieces can be placed in any order. The solutions are the same as Riviclia's Pelican.

In case of the third form, below is another way, discovered by MalaiABUeditor. Perfect Clear is easier to spot here because there are fewer solutions. This one only needs S then J then O. The one above is also possible here.

Double Triple Cannon (2)
In case of the fourth form, one can make a Double Triple Cannon or a Double Triple Cannon 2. In the third bag, J should come before S and Z before O. In the fourth bag, if T comes late, then DT Cannon is possible. If T comes early then DT Cannon 2 is possible.


 * Double Triple Cannon 2