Perfect DT

Perfect DT (Perfect Double Triple / パーフェクト DT) is a setup invented by a Japanese player named Yuu. It resembles a TKI 3 Opening but with the L placed upright on top of S which makes it looks kind of like a "wing". Usually made to achieve a T-Spin Double which could then be continued with T-Spin Triple without wasting a single T and usually ends with 8th row Perfect Clear. This is one of the only discovered setups that could achieve 8th row Perfect Clear without wasting a single T (other setups like Albatross Special and Pelican could only do Perfect Clear after 10 cleared lines). This setup could be made with an early I and S have to come before L. Perfect Clear after 14 lines is also possible.

T-Spin Triple
This setup is usually continued by T-Spin Triple. Notice how JI and LO could be swapped which increases the chance to score a T-Spin Triple without wasting a single T. It uses an unusual overhang but it works nonetheless.

If J comes early but Z comes before I, one could still create a T-Spin Triple with Z placed vertically on top of J.

T-Spin Double
If it is impossible to make a T-Spin Triple on the second bag, one could still continue with a T-Spin Double. The chance to stack this one is 100% because O, S and Z can be stacked in any order.

The O, S and Z pieces can be stacked in one of four ways:

It is possible to continue the T-Spin Double with Type 1 ST Stacking. Here is an example:

3 Bag Perfect Clear
If one did the normal setup, then there is a 75.87% chance to do a Perfect Clear after 8 lines.

Mirrored Setup
On the other hand, if one did the mirrored setup, then there is a 74.33% chance that it could end with 8th row Perfect Clear. The probability is lower because fewer I-Spins work there.

Form 1.1
If one cannot make a Perfect Clear after 8 lines, sometimes, they can achieve a PC after 14 lines. For this form, O should come before S and T.


 * 96.07%: An STSD. There are two ways to stack it. Only O should come before J (first diagram only). A few solutions can make a T-Spin beforehand.

If one cannot make a Perfect Clear, then they may transition to LST Stacking.

Here are some additional stacks, though not necessary to memorize.


 * 96.11%: There are three ways to stack and has a high probability, but cannot make a T-Spin during Perfect Clear.

Below are examples of a T-Spin that can be made from this form (the second example shows an STSD).


 * 99.13%: This one has a high probability, but has so many solutions and is a bit unsuitable for Perfect Clear. It is better to make a T-Spin instead.

Below are examples of making a T-Spin from this form:

Form 1.2
One is always able to stack their third bag like this; only the ZOS shape varies. However, there will be one hole clogged after the TSD.

Use the fourth bag to open the hole. Some examples (the fourth example shows forecasting):

In this form, 5-bag Perfect Clear is possible, but its efficiency is too low to memorize. Below is an example of how the fourth bag might be used (93.57%):

Form 2
For this form, Perfect Clear after 8 lines is impossible, so use any of the three forms below.

Form 2.1
Use this whenever O comes early in the third bag.


 * 95.40%: An Imperial Cross. T-Spin Double is often possible before the PC and four solutions. Only S needs to come before Z and T.


 * 99.88%: It has a high probability and is not difficult to create, but T-Spin cannot occur during a Perfect Clear.

If one cannot make a Perfect Clear, they can make a T-Spin. The fifth and sixth examples show King Crimson and T-Spin Triple, respectively.


 * 100%: Although the probability is 100%, the above form is better. Also, one cannot even make a T-Spin in bag 5.


 * 12-line PC: 54.29%, 14-line PC: 33.33%: The probability is not high, but the outcome is flat.

Try King Crimson if Perfect Clear is not possible.

Form 2.2
Try this form if one gets an early S.


 * 28.89% + α : It is easy to memorize because there are few solutions and one can do a T-Spin.

If one cannot make a Perfect Clear, make a T-Spin. The third example shows a T-Spin Triple Tower with a TSS beforehand.


 * 51.55%: Perfect Clear is possible, but try making a T-Spin instead.


 * 16.67%

Form 2.3
If one cannot make any of the two above forms, then try this form. Always possible if they get an early Z.


 * 12-line PC: 54.29%, 14-line PC: 33.33%: Only J needs to come before O. The solutions are the same as the last form in Form 2.1.

One can also try making a T-Spin this way.