From Hard Drop - Tetris Wiki

Contents 1 3-Celled Well Patterns 1.1 000 / 000 1.2 001 / 100 1.3 002 / 200 1.4 003 / 300 1.5 010 / 010 1.6 011 / 110 1.7 012 / 210 1.8 013 / 310 1.9 021 / 120 1.10 022 / 220 1.11 023 / 320 1.12 101 / 101 1.13 102 / 201 1.14 103 / 301 1.15 202 / 202 1.16 203 / 302 1.17 020/020

3-Celled Well Patterns

000 / 000

001 / 100

002 / 200

003 / 300

010 / 010

011 / 110

012 / 210

013 / 310

021 / 120

022 / 220

023 / 320

101 / 101

102 / 201

103 / 301

202 / 202

203 / 302

020/020

Avoid this situation if you do not want to waste an I tetromino.

LI/JI - 100/001