Mainspring Tower is a set of 2 different double-sided tower opener variations created by Winterfrost. When used together the build chances for either is 47% with mirrors and 31-34% without. Credits to Rixen/ReallyNotSomeone and epicgamer for some help with the opener.
TST Tower Version
The first bag of this opener can be built 36% of the time if the mirrored setup is considered and 23% of the time with only one side. The second bag and onwards can always be built. For the second bag, 2 setups will allow it to be built 100% of the time without the need for 180 rotations or gravity waits. In the third bag, T needs to be placed before S or the line clear will make it unplaceable.
The fourth bag is executed as below.
After the fourth bag, freestyling into midgame should be relatively easy, but there are some optional setups possible like the Mini-Triple below. The Z piece in the fifth bag may need gravity to be placed.
The first bag of this version can be built 31% of the time with mirrors and 16% of the time without. The second bag and onwards are always buildable, and the L should be held and placed last in second bag.
The third bag can always be built with one of these S placements. They both lead to the same field after the fourth bag, and L can be spun in after Z via clockwise or 180 degree rotations.
The fourth bag's S piece will fill where the third bag's could not. The L piece can be spun in if necessary.
After the fourth bag, it's possible to go into a Trinity to clean up the field or you can freestyle instead.
This path can always be taken if you want to go into normal stacking, the I piece should be held until it can be placed on the Z.
If you want to go into STSD Snaking, you can use this path. The I is held again and placed on the O after you T-Spin.
