Dolphin

Dolphin (previously known as Misfire-Beta) is an opener developed by Kerrmunism, intended to be used mainly in TETR.IO for bags where Misfire isn't applicable. It's notable for having many freestyle ways to stack, as well as potentially being a (worse) alternative to MKO Stacking. The opener consists of a T-Spin Single, followed by a Single Double shape into a DT Cannon or Fractal, or a second bag STSD.

In all cases on this page, if you see a transparent piece, it means you should place it after the T piece in your current bag.

First Bag
The first bag will always be stacked like this. There's a number of dependencies, being that you need to be able to stack the pieces L, S and O in that order.

Second Bag
The second bag is mainly built using this method, forming a Single Double which all future continuations will be built based off of. In games that have 180 (such as TETR.IO), you'll be able to place your J after your L has already been placed, making the opener much more viable than in other guideline games.

You can also stack the second bag using these methods, though the follow-ups would be different.

There is one alternate stacking method in particular that requires a closer look however.

B.A.S.S Method
Standing for "Best Alternative Second Stack", this method gives you an immediate TSD for the second bag, with extra damage potential available. It also tends to be safer to stack when available.

Build the second bag like this, placing your S (or Z, if you put your S first on the other side) after your T

From here, you have various options available.

4-5 Stacking

Cut Copy

Fractal

T-Spin Triple

Double Triple Double

Trinity

Try to adjust the method you use to stack the second bag according to your opponent's game plan and your current board state.

Ahab's Whale
This is an unlikely, though devastating Perfect Clear continuation for the Cut Copy build shown above. Start by building that, shown again below.

After this, build like below, if at all possible. You'll need your T to be one of, if not the first piece to come in your fifth bag in order for the Perfect Clear to work properly. You may also be able to hold all your Ts from the third, fourth and fifth bag together to form an incredibly powerful spike, which will also work.

At this point, assuming your board looks exactly like seen above, you have an 84.44% Perfect Clear chance with 2 minimals.

After the perfect clear, you will be back to a fresh bag, which you can use to make this opener again or another opener.

Third Bag
There's various continuations that you can do after the second bag's main build, namely setting up a DT Cannon or a Fractal.

Fractal
A fractal can be stacked in the third bag using various methods. Namely, you just need to make the shape below, with the ghost piece representing any block.

Some examples are shown below.

DT Cannon
A DT Cannon can always be built in the third bag if you're playing in a game with 180 spins by using the method below. You may have to place your T pieces before the entire structure is finished being built, but you will still always be guaranteed a T-Spin Double into a T-Spin Triple.

Depending on what your board looks like after the DT, you may be able to build a C-Spin after your DT. The T (purple) minos in this diagram show extra bits that would need to be filled in.

Shamu Special
This is a meme continuation that can be performed after the DT Cannon performed in this bag if you're playing a game with 180 Spins. Stack using one of the following paths:

After this point, the paths will be the same, and both follow the same pattern shown below. The placement of the S (Z if mirrored) and I pieces in the first two diagrams will depend on which path you used before.