Captain Stacking

Captain Stacking is an opener that starts with a T-Spin Double and chiefly results in a nice chance for a Perfect Clear after a further T-Spin Double, mostly after 6 or 8 lines. In the first bag it requires an early I piece. The Z piece is kept on hold as it will be used in different situations. TKI 3 Opening variants are also frequently used for such first bags.

There are so many ways you can make Perfect Clear after the T-Spin Double in the second bag. If a piece is split into 2 parts in a diagram, it means that the piece must be inserted after the T-Spin line clear. If a diagram contains less than 7 pieces (not counting the first bag's Z piece), it means that the missing piece can be kept on hold while filling the empty cells with the 2 first pieces of the third bag.

These continuations have the missing piece kept on hold while filling the empty cells with the 2 first pieces of the third bag.
 * J and L: Either the I, O, S or Z piece is held.


 * O and I: The Z piece is held. There is only one way if the Z piece is placed vertically on J.

If the Z piece placed as shown, it will form the same shape as TKI Flat Top. It can be continued with any of the following.

Perfect Clear after 8 lines
To be constructed
 * O kept on hold (100.00% PC rate, 31 minimal solutions)


 * SI → O (99.68% PC rate, 14 minimal solutions)


 * L → O (95.00% PC rate, 23 minimal solutions)


 * J → O (87.82% PC rate, 11 minimal solutions)


 * O → L (Compromise, 48.89% PC rate, 14 minimal solutions)