The values of the letters in Scrabble were assigned according to the front page of a US newspaper in the 1930s. Is it time the scoring system was updated to reflect today's usage?
According to Lewis's system, X (worth eight points in the current game) is worth only five points and Z (worth 10 points now) is worth six points.
Other letter values change too, but less radically. For example, U (one point currently) is worth two in the new version, G (two points) becomes three and M (three points) becomes two.