Mini Triple Double

Mini Triple Double (or abbreviated as MTD Attack) is a class of openers where one starts the game with a T-Spin Mini Single followed by a T-Spin Triple and a T-Spin Double, usually by using the first 3 T pieces. It behaves similar to STD Attacks (see Mr. T-Spin's STD and pwn's STD), with the difference that the T-Spin Single is substituted with a T-Spin Mini Single. In both cases, the single line clear is used to prepare a Triple Double Attack (also known as C-Spin). T-Spin Mini instead of T-Spin Single sends fewer lines but it can result in a higher chance to achieve a Perfect Clear after 8 cleared lines in total. Note that starting with a T-Spin Mini Single does not send any lines in most games but it will enable the back-to-back bonus. However, there are also games like Tetris Battle or Tetris Online Japan where T-Spin Mini Singles will send a line and where T-Spin Triples are especially powerful with back-to-back bonus.

Joystick
Joystick is an example of an MTD Attack. The name originates from the left part of the setup after the first bag: the L+J piece combination forms a shape which looks like a joystick. Note that L and J can be dropped in any order; the only important thing is that O piece must be placed before I piece in the first bag.

If possible, stack the second bag like shown below (resulting in a T-Spin Triple). The first pieces of the third bag can be used to fill the bottom 2 lines to get a T-Spin Double (thus Mini Triple Double). With some luck one can also get a Perfect Clear: 75% of all third bags can result in a Perfect Clear after getting a T-Spin Single (sometimes even Double). This chance increases to 82%, if ignoring the T-Spin line clear.

Here is another way to clear a T-Spin Triple at the end of the second bag (in case one has to place J before S). However, this one is worse because it leaves an even number of cells empty below the T-Spin Triple. This worsens the chance for a Perfect Clear after 8 lines. In fact, there is no way to get a T-Spin Single (or Double) and a PC both at the same time. 44% of all third bags can result in a PC, if not going for the T-Spin line clear.

TD Parfait
The following setup is called ＴＤパフェ in Japanese, pronounced TD Parfait (TD = Triple Double, Parfait = Perfect Clear, parfait means perfect in French). It is another example of an MTD Attack. One interesting thing about this opener is that the T-Spin Triple can be stacked with its mouth facing both sides. Preparing the T-Spin Triple with the J piece (first 2 options) is favored because this will give a good chance for a Perfect Clear after 8 lines.

In case of the first option, 76% of all third bags can result in a Perfect Clear after getting a T-Spin Single (sometimes even Double). This chance increases to 96%, if ignoring the T-Spin line clear.

In case of the second option, 66% of all third bags can result in a PC after getting a T-Spin Single (or Double). This chance increases to 85%, if ignoring the T-Spin line clear. However, those Perfect Clear solutions are usually hard to spot, if T piece comes late in the third bag. There are many options but none of them offers a significant probability. Note that L piece can be placed after Z piece in the second bag.