Why seven letters on a Scrabble rack?
I’ve read a lot on Scrabble history and have never seen this addressed directly. It is clear that Alfred Butts chose this number when he first began experimenting with what would eventually be called Scrabble. It is also clear that Mr. Butts did painstaking research on letter distribution in the English language. My best guess is that he discovered that the average word length in English is close to five. Further, he likely determined that the vast majority of English words can be spelled with eight or fewer letters. With seven tiles in the game, most words will be formed with eight or fewer letters. The other factor is the difficulty of forming words. Too few letters and the game becomes nearly impossible to play. Too many and the game becomes ridiculously easy.
