TKI stacking: a T-spin double from the first seven pieces

TKI stacking builds a T-spin double from the first bag alone: the finished shape, the stacking order, how to spin the T in and when to use the mirror image.

October 5, 2026

TKI stacking is an opener that builds a T-spin double from the first bag (seven pieces) alone. With 7-bag the first seven pieces contain one of each kind, so as long as the order works out you can always build the same shape. It uses fewer pieces than the DT cannon, and its strength is that the first T-spin comes early. For how to put the T in for a T-spin double, read “T-spin basics: the T-spin double” first.

The finished shape

The finished shape with six pieces stacked. The bottom cell of the third column from the left and the three cells in the row above it are empty. The dotted outline is the T (T-spin double).

Six of the seven pieces, all but the T, build the slot, and the T goes in last. Each piece has the following role.

I: flat on the floor. It is the floor on the right-hand side of the slot.
L: upright at the left edge. It is the left wall of the slot and the left side of its bottom.
Z: flat on top of the I. Its top-left cell sticks out over empty space and becomes the overhang.
S: upright to the right of the Z. It fills the second row from the bottom.
O: at the right edge.
J: flat on top of the S and the O. The T-spin double works without it, but placing it makes what comes next easier.

Stacking order

① Three pieces that sit directly on the floor: I (flat on the floor), L (upright at the left edge) and O (at the right edge). These three can go in any order.

② Place the Z flat on top of the I, and stand the S upright to its right. Both the Z and the S come after the I.

③ Place the J on top of the S and the O. Finally, put the T in.

There are only three rules.

Place the Z and the S after the I.
Place the J after the S and the O.
The T goes last. If it arrives early, keep it in hold.

While the T is in hold, you cannot use hold to put off any other piece. If the six pieces that come after the T arrive in an order that cannot follow the rules above, consider the mirrored shape described below.

Putting the T in

Rotate the T counter-clockwise so that it stands upright (the nub points left).
Move it two cells to the left, so that it is directly above the empty column.
Soft drop it to the bottom.
Rotate counter-clockwise once. The T tucks in under the cell of the Z that sticks out.
Hard drop to lock it. T-spin double.

After the T-spin double. The top of the L, the upper halves of the Z and the S, and the J remain.

The mirrored shape

The shape mirrored left to right. Instead of the L, stand the J upright at the right edge, and instead of the Z, use the S as the overhang. The T goes in with clockwise rotations.

Depending on the piece order, the mirrored shape can be easier to stack. Telling which to use is simple: whichever of J and L arrives later goes on top last. If the J is later, use the standard shape; if the L is later, use the mirrored one. The piece that goes on top can only be placed after the others, so it suits you better when it arrives late.

	Standard	Mirrored
Piece stood at the edge	L (left edge)	J (right edge)
Piece that forms the overhang	Z	S
Piece that goes on top last	J	L
Rotation of the T	Counter-clockwise	Clockwise

When it does not work

The I takes a long time to arrive. The I is the foundation, so while it is missing neither the Z nor the S can be placed. Place the L and the O first, and keep just one piece, the Z or the S, waiting in hold. If that is still not enough, give up on TKI stacking and stack flat.
The T went in, but it only says “Double”. Check that the overhang (the top-left cell of the Z) is directly above the T. If you place the Z one cell too far to the right, it does not form an overhang.
You block the column that should stay empty. Check two things: that the L is pushed tight against the left edge, and that the I is not too far to the left (it starts in the fourth column from the left).

In Setup Drills, “TKI stacking” lets you practise either the standard form or the mirrored one. The piece order changes every time. Start with 20 runs with the dotted targets shown, then see whether you can reproduce the shape without them.

Practice this