The Yackspin is a troll TKI followup created by 2 French players named Yack Tenebreux and Trixciel. Although some people might find this setup viable for competitve play, it's mainly used to show off your SRS+ knowledge. It's with noting that this only works if the game has a 180° rotation button and SRS+. Yackspin is a TSD>TSD>TST>TSS opener with multiple Polymer T-spins.

1st bag

After building a TKI Flat Top, and clearing the T-Spin, you should be left with this shape:

2nd Bag

A T must be wasted. This setup requires to stack pieces high up the board in the 1st bag, and that's the main liability that comes with it.

First route

T or I has to come before L or J.

Second route

Early S

3nd Bag

A Fin T-Spin Double is needed to go further down this road. It requires a specific rotation sequence.

Soft Drop

Counter-Clockwise

180° Rotation

Clockwise

With the spin logic out of the way, here are 4 patterns that leave you with an OK stack. If you can't do any, you should try to build the best you can.

Early S/Z

Early L/J

4th Bag

From this point onwards, the only thing that matters is the Iso T-Spin Triple or TrIso T-Spin. The other pieces can be placed as the player wishes.

Soft Drop

Counter-Clockwise

180° Spin

Counter-Clockwise

After a Yackspin

There are quite a few options a player can choose after a Yackspin. There's no particular continuation, but the player could definitely take the T-Spin Single, increasing their Back-To-Back by 1, and leaving them with a 0-9 stack.

Soft Drop

Counter-Clockwise

180° Rotation