This is a quick hack to produce stems as per Stewart Holden's recent post
on world-scrabble.

The ideal function would be to use the number of *unique* letters that
a stem combines with, and an evaluation of the probability function for
having picked the base stem, to order the best 250 stems.

That's not what I've done.  This code orders the stems by the number
of words each stem can contribute to.  This is not quite the same thing, as
we double-count stem+letter when more than one word can be formed.  I guess
a quick hack to correct this would be to strip anagrams from the input
word list before running this code.  I may add that later, but for now
this is a quick 30-minute hack that seems useful.

Attached is the list of the first 250 6-letter stems.

You'll need a word list.  Save it as "wordlist.txt" to use with this code.

Graham