T-SPINS · LESSON 1 OF 6
What makes a T-spin?
AFTER THIS GUIDEYou can inspect a locked T, count its pivot corners and explain why a T-shaped landing alone does not prove a T-spin.
The game checks the move, not just the silhouette.
A T-spin starts with a T rotated into its final position. In the common SRS-style test used here, at least three of the four diagonal corner cells around the T’s centre must be occupied. Board boundaries can count as occupied. The corner cells are not the four cells of the T itself.
Full versus Mini is a second check. The two corners on the side the T points towards are its front corners. Both occupied normally gives a full spin; one can give a Mini. Some kick tests override that distinction. Stacking Lab implements the final test of a quarter-turn kick sequence as a full-spin exception. Do not assume every 180° rotation receives the same exception.
Finally, count the rows cleared. A recognised full spin clearing two rows is a T-spin Double. A spin without a clear can still be recognised. Moving the piece after rotation can change its recognition state; finish the intended entry and check the result rather than adding unnecessary corrections.
Different games can classify edge cases differently. Start with an ordinary TSD, then learn the exceptions for the game profile you actually use.
Count first. Rotate second.
Locate the pivot
In the corner diagram, find the centre marker. Check the four diagonal cells around it, ignoring the empty cells beside the arms. Three occupied corners pass the first geometry check.
Watch the final turn
Step through the TSD diagram. The T enters vertically and turns under the roof. Compare the orientation before and after the turn; this is the action a straight drop cannot replace.
Separate the result
After the turn, two rows clear. “T-spin” describes the placement; “Double” describes the two cleared rows. Neither name tells you a universal attack value.
Three outlined diagonal cells are occupied; one is empty. The required final rotation and Mini classification still matter.
The T is in position beneath the overhang.
One clockwise turn completes two rows.
T-spin Double: two lines cleared.
Common mistakes
Counting the arms as corners
Draw the 3×3 box around the pivot. Its four corners are the cells to test; the T’s own arms are different cells.
Rotating anywhere and expecting a spin
A rotation high above the stack does not make an ordinary T placement a useful spin. The final position, move history and recognition rules must agree.
Calling every small spin a Mini
Mini is a classification, not a casual description of how much the piece moved. Check the front corners and kick rule.
TAKE IT TO THE BOARD
Explain three recognised spins
- Open TS practice with Gravity Off and NEXT 5. Build manually or watch the coach until a TSD is ready.
- Before executing, point to the pivot, three occupied corners and the two rows you expect to clear.
- Make the move, then compare the event label with your prediction. Repeat for three examples; use Undo to inspect an unexpected result.
What counts as progress? You can name the recognition conditions separately from the number of rows cleared.
Open practice ↗Opens the mode. Set Gravity and NEXT yourself; your current settings are kept.
Keep these terms nearby
NEXT IN THIS PATH
Building your first TSD
Find the slot, build the overhang and keep the entry open.
Read the next guide →Further reading
For setup variations and additional examples, see FOUR: T-spin recognition. The practice task here is original to Stacking Lab.