Playing forever

From wiki

The following outlines a method of playing forever given the following conditions, which apply in many Tetris products since 2001:

• the Random Generator is used to generate piece sequences
• the game has the Hold feature
• at least 3 piece previews are available

Contents 1 Standard procedure 1.1 The S, T, and Z piece loop 1.2 The L, J, and O piece loop 1.2.1 Advanced techniques for when only 3 previews are available 1.2.2 Tricky starts when only 3 previews are available 1.3 The I piece loop 2 Balancing the Stacks 2.1 The L, O piece loop 2.2 The I, J piece loop 2.3 Putting it all together 2.4 The Final Bag 3 Open questions 4 See also 5 External links

[edit] Standard procedure

The general method is achieved by dividing the screen into self contained sections as shown below. Specifically, the 4 left columns, the 4 right columns, and the 2 middle columns will be treated as distinct regions, with specific pieces assigned exclusively to each region. Because the random generator provides strings of bags containing each of the 7 pieces in a random order, it is possible to construct a strategy around the relatively small variation, with looping patterns.

S, T, and Z will be placed to the left, L, J, and O will be placed to the right, and I pieces will fill the middle.

[edit] The S, T, and Z piece loop

This pattern loops after 4 bags of pieces. Depending on the order of the pieces for each bag, you may need to use Hold to force a piece to come last. Piece previews are technically not required to play this pattern.

The Z piece must drop after T, so use Hold to change the order if necessary:

The T piece must not drop first, so use Hold to change the order if necessary:

Option 1

Option 2

The T piece must land diagonally adjacent to the other T, so use Hold to change the order if necessary:

Option 1 (needs T before S)

Option 2 (needs T before Z)

The T piece must drop last, so use Hold to change the order if necessary:

[edit] The L, J, and O piece loop

This pattern loops after a single bag of pieces. Depending on the order of the pieces, you will need to use a different construction. At least 5 previews are required to choose the appropriate construction. Alternatively, it is possible to use 3 previews and clever use of Hold (that does not conflict with the STZ loop's Hold needs) to choose an approriate construction using some advanced techniques.

O first (OJL, OLJ):

O last (JLO, LJO):

JOL: (mirror for LOJ)

Drop J

Soft-drop O

Slide O