ZOS Tower (Japanese name: ZOSタワー) is an opener to set up STSD after TSS. Overall, it requires less softdrop times and can be stacked quickly. This opener was invented by Sioyaki.

1st bag

It performs TSS, so named because it can be loaded when Z>O>S and can tower with ZOS. Setup rate is 33.33% on one side and 58.33% on both sides.

2nd bag

ideal shape

ideal shape

compromise shape

always Dulse Flame

Perform TSD. 91.67% of the time, the ideal shape can be stacked to produce a TSD. If not possible, TSD can be done with compromise shape. If terrain is important, Dulse Flame is always possible without using T-pieces for Spin.