Line clears and scoring
From Singles to Quads, T-spins, back-to-back, combos and perfect clears: an overview of how each kind of line clear is scored and how it is detected.
When a horizontal row is completely filled, it disappears. This is a line clear. But not all clears are worth the same. The same two-line clear scores four times as much with a T-spin as it does the ordinary way. This page sorts out the types of line clear and the three bonuses that raise your score: back-to-back (B2B), combos and perfect clears. The point values are the ones used in this site’s practice modes.
Types of line clear
A single piece can clear at most four lines at once. The name depends on how many lines are cleared together.
| Name | Lines cleared at once | Base points |
|---|---|---|
| Single | 1 | 100 |
| Double | 2 | 300 |
| Triple | 3 | 500 |
| Quad | 4 | 800 |
A Quad is only possible with a vertical I piece. Leave one well open at the edge, stack four rows, and drop the I in. This is the first “clear several lines at once” shape to learn.
T-spins are counted separately
When you put a T piece into a gap by rotating it and it locks there, that is a T-spin. Lines cleared with a T-spin score far higher than the same number of lines cleared normally.
| Name | Lines cleared | Base points |
|---|---|---|
| T-spin single | 1 | 800 |
| T-spin double | 2 | 1200 |
| T-spin triple | 3 | 1600 |
| T-spin mini (single) | 1 | 200 |
A T-spin double is one piece and two lines for 1200 points. That beats the 800 points of a Quad, and it needs only half as many rows. This is why intermediate players learn T-spins.
How a T-spin is detected
There are two conditions.
- The last action on the T piece was a rotation (no sideways move or drop after the rotation).
- Of the four diagonal cells around the centre of the T, at least three are filled by blocks or walls.
Of those four cells, if both of the two on the side the T’s nub points to are filled, it is a regular T-spin; if only one of them is, it is as a rule a T-spin mini. A mini scores little, so the regular T-spin is the one to aim for. “T-spin basics: the T-spin double” explains how to build the shape.
Back-to-back (B2B)
Let’s group Quads and T-spin line clears together and call them “difficult clears”. When you make difficult clears one after another, the base points of the second and later ones are multiplied by 1.5. This is back-to-back, or B2B.
- Quad → T-spin double: the second clear scores 1200 × 1.5 = 1800 points.
- A Single, Double or Triple in between breaks the B2B.
- Placing pieces without clearing any line does not break it.
To keep B2B going, you have to stack by the rule “when I clear, it is a Quad or a T-spin and nothing else”. Take this on once your flat stacking has become accurate.
Combos (Ren)
Clearing lines with every piece you place, several times in a row, makes a combo. Two clears in a row count as a 1 combo, three in a row as a 2 combo, and the combo count × 50 points is added. Place even one piece that clears nothing and the combo goes back to 0.
Perfect clear
If a line clear leaves no blocks at all on the board, it is a perfect clear (PC). A bonus is added depending on the number of lines cleared.
| Lines in the final clear | Bonus |
|---|---|
| 1 line | 800 |
| 2 lines | 1200 |
| 3 lines | 1800 |
| 4 lines | 2000 (3200 during B2B) |
In versus play a perfect clear is worth even more than its points. It sends a big attack to your opponent while your own board goes back to empty. That is why this site focuses on perfect-clear stacking.
Summary: what to aim for
- First, get consistent at Quads by dropping an I into a well at the edge.
- Next, learn one T-spin double shape.
- In the opening you can go for a perfect clear. Thanks to 7-bag, the first ten pieces are easy to plan.