Each piece has a nickname: I, O, T, L, J, S, and Z. Practice recognizing them instantly and knowing their rotation patterns. The S and Z pieces are the trickiest — learn to fit them into tight corners.
There is no secret code. The difference between a score of 5,000 and 50,000 is practice. Play for 15 minutes every day. Your brain is a muscle; Tetris is the workout. Tetris Computermeester