F-Spin

F-Spin is an Polymer T-Spin opener that usually results in a Iso-T-Spin Triple in the second bag and a T-Spin Triple in the third bag into Super T-Spin Double in the fourth bag. Note that Iso-T-Spin Triple can only be done on games which have 180° rotations and SRS 180° kicks, like Tetr.io.

First bag
The second setup has a better build chance, but needs more key presses.

Variant 1
The main and best continuation.

Second bag
S>Z

Third bag
100% with 180 rotations

Fourth bag
if you can stack JZ like this, it will result in a better stack

Perfect Clear after 8 lines
46.7%, 97.7% early S. 4 minimals

TSD into DT Cannon
When it is impossible to build the main continuation in the second bag, you can freestyle the STMB Cave or use these T-Spin Double into DT Cannon continuations (found by Zera)