Dot Cannon (ドット砲)/Seven Seas Stacking

Document by: myaobyao!#3892        @ame_lia#3892         @papersephone

Original page available here.

Dot Cannon, also known as Seven Seas Stacking, is a Japanese TD>PC opener not to be confused with the (notoriously) popular DT cannon.

Compared to Gamushiro and MS2, Dot Cannon excels in only needing one build path without varying 2nd or 3rd bags, also needing only 5 minimals for a Perfect Clear coming in at an 85.24% chance to PC.

Being an 8-height PC, it will also allow you to follow up with DPC, similar to most other TD openers.

Note: All the entries past 3rd Bag PC were researched and experimented by me, if there are any optimizations kindly DM me for any recommendations.

Cheers!

1st bag

The only requirement for building this bag is J before S, as long as you do not put down the L piece first.

You will have a 91.47% chance of building it without the mirror, or 100% with it.

2nd bag

The 2nd bag can also always be built this way, given that you have soft drop as well as 180 rotations.

If you end up getting J, O and T before L (without the Z piece to land on), you may have to compromise with the following. This has a low chance of occurring, at only 5%.

It’s useful to keep in mind for high gravity runs like in Blitz. Note that you can just wait for gravity in versus gameplay, as shown below:

3rd bag PC

You will be left with this field after the TD:

There are only 5 minimals, with the first one alone yielding a 55.87% chance to PC.

If you happen to receive 2 or more lines of garbage below the T-spin, it is viable to opt for a TSS instead of a TSD, as shown below:

3rd bag Kaidan (credit to: orz)

You can also opt out into a Kaidan in the 3rd bag.

3rd bag Imperial Cross

If the PC fails, you can opt out into an Imperial Cross, which also has a chance to PC.

The only prerequisite to building this is an early Z piece.

There is also an alternate build for the Imp Cross, which is rarely needed but is useful to know regardless:

4th bag heart PC

Given an early I, there is a 17.14% chance to PC with the remaining field:

Only 6 minimals are required below, which will put you on 7th PC:

Solves are mostly intuitive.

4th bag STMB cave

In case a PC cannot be built, you can opt out into an STMB cave.

Note that the T used here will be the T from the 5th bag, as the 4th T will be required to finish the Imperial Cross.

It’s also useful to note that you can chain both of the Ts together (i.e. the second T in the Imperial Cross) for more spiking potential:

5th bag T-spin

A simple T-spin can be built by using S, with the overhang as a Z or L.

You can transition into 4-5 from this as well.