Original Rotation System

The black dot marks the segment of the piece which spawns in row 20 column 6. It's also the axis of rotation (except for the O piece, which doesn't rotate).

Original Rotation System is the rotation system used in the original Tetris game for the Electronika 60 and the IBM PC Tetris game.

It is identical to the right handed version of the Nintendo Rotation System, except that the horizontal orientation of the I piece is one block higher.