Tactical rotation

The New Tetris uses smooth falling animation for tetrominoes. The way this implementation mixes the falling animation with collision detection means that when a tetromino must be moved under an overhang to reach a ledge, by the time it has moved left one space with no support it has dropped more than zero spaces. In some cases it can therefore not reach a ledge.

Nothing can be done in the case of the O piece:

There are, however, ways of getting a piece other than O further under the overhang by making use of "tactical rotation": rotating the piece in the right direction at the right time. The rotation system allows such twists.

With L and J pieces
This is useful for completing spiral L monosquares on the left and spiral J monosquares on the right (in which case the move is reversed) if the space above the block is already occupied in such a way that the L cannot be overhung as in the second figure of the L/J shuffle below. With the opposite multisquares (L on the right or J on the left), the third piece requires some tactical rotation if there is not enough support underneath. If there is sufficient free space above the construction, an easier method can be used (shown below).

L/J swing
This is useful when building a spiral L monosquare on the right or a spiral J monosquare on the left as above, provided there is enough free space above the construction.

L/J shuffle
This is useful for completing spiral L monosquares on the left and spiral J monosquares on the right (in which case the move is reversed).

S/Z pop
This move is required for ZLLZ/SJJS, TTLZ/TTJS and LJZI/JLSI multisquares. All rotations should be reversed for the right-hand versions.

Building a T monosquare quickly
The quickest way to add the final piece of a T monosquare is to spin it into place: If there is no free space above: