C-Spin

The C-Spin (TKI積み) is a kind of Triple Double Attack. It is invented by TKI. This name is given because of the "C" shape that is formed by the J and L. As the name suggests, it results in a T-Spin Triple which is usually followed by a T-Spin Double within three bags. As an opener, it is most often built with an ZST core whereas L and J are used to build the overhang.

It is difficult for beginners to use the C-Spin opener because accidents are likely to happen.

C-Spin Opener
There are many C-Spin openers, both with a vertical T and horizontal T piece. In this page, some of the most notable setups are listed. However, for some openers, stacking the second bag is fixed.


 * ZST Core: This is the most common C-Spin opener. You must stack the second bag spontaneously. However, if you can place the Z piece early, the whole stack will be stabilized. Below is an example with a Trinity followup in the third bag.



Similarly, you can use a Donating T-Spin Triple technique. This will work if either the I or O piece is still on hold (I piece held in this example).

Additionally, similar things are also possible in the case of a 2-columns wide gap, especially the third diagram shown below.




 * TOJ Core (TKI signature): In the second bag the S, Z and O pieces always form this "Plus" shape which can be done in 4 different ways. If you are aiming to achieve a Perfect Clear in the third bag, you must place the pieces differently, except for J and T.


 * IST Core: It is best if the first O piece is placed on the far right as this will allow the second bag to be always stacked differently, alongside the traditional way. In the case of the latter, it is continued with a Trinity.


 * TZJ Core: This setup is invented by Aitch. This setup can always be assembled if the I piece comes early, although the TKI 3 Opening is more appropriate in the case of that. Normally, the J piece would be on hold, but for this example, it is placed on the L piece. You must spontaneously stack in the second bag. For example, the S, Z and O pieces are placed along with a late L piece.


 * ITZ Core: Like the ZST and TZJ Core setups, the second bag is stacked improptu. However, there are quite some ways you can stack the second bag in such a way you can achieve a Perfect Clear after 6 or 8 lines in the third bag.

C-Spin Opener Continuations
There are several ways you can stack the third bag after the T-Spin Triple.

T-Spin Triple and Imperial Cross
No matter how wide the gap between the overhang and the stack on the right is, you can replace the T-Spin Double with a T-Spin Triple or Imperial Cross after the T-Spin Triple from any C-Spin setup.

STMB Cave
The STMB Cave continuation will only work if the following cells in diagram 1 (marked with X's) are free. If one of them is occupied, you can try making a T-Spin Triple or Imperial Cross.

LST Stacking
Generally, if you have a 2-columns wide gap, you can continue to LST Stacking by placing a Z or, in this case, L piece on the overhang. Addionally for this example, in the third bag, the Z piece is placed after the T-Spin Double.

Perfect Clear after 6 lines
The usual C-Spin opener to achieve a Perfect Clear after 6 lines is built with a ZST core. This continuation for this C-Spin opener is discovered by Chopin. There is a low chance to stack the right side perfectly flat with a 3-columns wide gap to the overhang while keeping the unused piece on hold, but if you can stack it, you may have a chance to get a Perfect Clear. You may have to sacrifice the T-Spin in order to achieve a Perfect Clear, particularly if the I piece is the remaining piece left.

If you cannot execute a Perfect Clear after 6 lines, there still may be a chance to execute a Perfect Clear after 8 lines. Otherwise, it can be continued with a T-Spin Triple, Imperial Cross, STMB Cave or T-Spin Double.

Perfect Clear after 8 lines

 * Main article: C-Spin Perfect Clear

Most C-Spin setups can be stacked in a way that can result in a Perfect Clear after 8 total lines in the third bag. For example, using the TKI signature C-Spin opener, one can sometimes make the stack below and may also have a chance to achieve a Perfect Clear (41.90% for this example), though not always with a T-Spin Double. For more setups, see C-Spin Perfect Clear.