Also known as Microsoft's Best Of Windows Entertainment Pack or BOWEP for short.
Scoring
The current piece starts with an initial score value, which increases for each successive playing level. Each time you rotate the piece or move it horizontally, its score value decreases.
If you drop the piece, its score value increases proportionally to the distance it falls. Therefore, you can achieve the highest score per piece by immediately dropping the piece from the top of the playing area. (The lowest score per piece will result when you continually manipulate the piece until it lands on another piece or the bottom of the playing area)
Programmers used integer variables to store points gained by the player, so in effect when you reach 32,767 your score goes to the beginning of the variable (which is -32,767).