The T-spin triple (TST): shape and entry
The T-spin triple clears three lines with one T piece: its slot, made of a well, a notch, an overhang and a shelf, and how a wall kick drops the T in.
A T-spin triple (TST) clears three lines at once with a single T piece. It is worth 1600 base points, more than the 1200 of a T-spin double. The T has to end up upright at the bottom of a deep hole, and it can never get there just by falling from above. What sets this move apart is that a wall kick “drops” the T into place. It is easier to follow if you read “T-spin basics: the T-spin double” and “Wall-kick rotation basics” first.
The shape of the slot
The slot is made of four parts.
- Well: one cell wide and three cells deep. The upright bar of the T goes here.
- Notch: one cell beside the middle row of the well. The nub of the T goes here.
- Overhang: one block directly above the well, with one empty row in between. It sticks out from the side opposite the notch.
- Shelf: the row just under the overhang. This is where the T lies flat for a moment.
The three lower rows must be completely filled apart from the four cells the T will occupy. Compared with a T-spin double, there is one more row to prepare and the shape is more complicated.
Putting it in
With the shape in this figure, soft drop the T onto the shelf, move it one cell to the left and press rotate clockwise once. If the notch is on the left, everything is mirrored.
Why it drops
When there is a block where the T is trying to rotate, the game tries to put the T in a slightly shifted position instead. This is the wall kick. There are five candidate positions, and they are tried in order.
- Rotate in place … hits the wall of the well.
- One cell sideways … hits the overhang.
- One cell sideways and one cell up … hits the overhang.
- Two cells down … hits a wall.
- One cell sideways and two cells down … fits.
The overhang’s job is to rule out the second and third candidates. Without it, the T would stop at the second candidate and never drop into the well. Remember it as “because the overhang is there, the game gets as far as the last candidate, and the T drops”.
When the space under the overhang is closed in
In the figure above, the shelf has the field wall on its left and the overhang on its right, so the T cannot be lowered straight onto the shelf. In this case, add one more rotation.
- Rotate the T clockwise so that it stands upright, and lower it against the left wall.
- Rotate counter-clockwise once. The T lies flat and settles on the shelf under the overhang.
- Rotate counter-clockwise once more. The T drops to the bottom of the well.
Choosing between the double and the triple
| Double | Triple | |
|---|---|---|
| Base points | 1200 | 1600 |
| Rows cleared | 2 | 3 |
| Depth needed | 2 rows | 3 rows + shelf + overhang |
| Ease of building | Easy to build from flat stacking | Mostly built as part of a fixed shape (a setup) |
If you are building a shape yourself in the middle of a game, start with the double. The quickest way to the triple is to use it inside setups that you “memorise as a whole shape”, such as the DT cannon.
Common mistakes
- Forgetting the notch. If the well is just a straight shaft, the nub of the T has nowhere to go and the T does not drop.
- No overhang, or one that is too high. The overhang has to be immediately above the end of the T lying on the shelf. If it is even one row higher, the T only shifts sideways and does not drop.
- Rotating the wrong way. Rotate towards the side with the notch. If you rotate the other way, the T just changes orientation on the shelf.