To further clarify 20G, a regular Tetris playfield is 21 blocks high and in 20G gravity your piece falls 20 in a frame. So, it doesn't technically spawn directl

To further clarify 20G, a regular Tetris playfield is 21 blocks high and in 20G gravity your piece falls 20 in a frame. So, it doesn't technically spawn directly on the stack, but it will fall on top of your stack before you can move it horizontally. It is only possible to play 20G if you have what is called TLS (Temporary Landing System) and IRS (Initial Rotating System) in TGM games. This means that even before your piece spawns and falls, you can rotate it by one rotation either clockwise or anticlockwise and when the piece drops, it doesn't lock into its' place immediately, you can move it for a short while. Also, if the piece drops vertically, the locking time resets which means that you should build a pyramid shaped stack so that you can slide your pieces down on either side and rotate it where you want it before it locks.