(Perfect Clear Guide)
Originally on harddrop community.
What is perfect clear (Zen Keshi) ?
Perfect clear is a bonus that is rewarded if you clear all the minoes.
How to make a perfect clear (Zen Keshi) ?
This guide tries to give a higher chance of successfully performing a ZEN-KESHI (Perfect Clear). The best scenario is to attempt it at the beginning of the game, when your opponent hasn't finished building up their stack. If you succeed, this usually becomes a K.O.
Note that this guide does not guarantee a 100% chance of success in making a perfect clear. It also requires a lot of understanding and practice to make it work in a game. However, failure is not as bad because you can continue making a stack for T-spin or Tetrises.
The process contain 2 steps.
- Create a stack that makes a perfect clear more possible
- Look for tetromino combinations that will make it succeed.
Stack for perfect clear (Zen Keshi)
This is a stack that makes a perfect clear much more likely, since it is built from a combination of every tetromino and has 12 holes in which fit the next combination of 3 tetrominos.
It consists of two parts that can be split. First is the 4x4 tetromino block. You can also split this part into 4x3 and 4x1, which works the same.
Second is the combination of TSZ, which is very important here. Note that you should get T before Z to make this shape.
Which means it is possible to create a shape like this.
or like this
or a mirror one applies to the similar theory(but not the same). Note the difference in TSZ combination.
Combining the Next Tetrominos for Success
Now lets assume you finished building your stack like the one below:
The next thing to worry about is what your next 3 tetrominoes will be. Note that you can use the queue to hold one unused tetromino. As a tetris player, you should know that the sequence is very important in many cases.
One successful positioning is shown here. This combination will work regardless of the order of tetrominoes. But L before T is easier, since otherwise you must use an L spin technique. Take note that you can insert the I piece at any point in the four line space during this combination.
first, insert L into the position by soft dropping it:
Then spin it clockwise once.
then insert the i tetromino (or t if it comes up next)
Resulted in a line clear making a perfect clear position for the T tetrimino