The Prize And The Odds
Playing all seven tiles in one turn scores an extra 50 points in Scrabble and 35 in Words With Friends, which is usually more than the difference between your best and second best play for the whole game. Of every possible seven tile combination, 26,732 spell at least one valid seven letter word. That is fewer than people assume, and it is why bingos are built rather than drawn.
Keep The Right Six
The richest rack in the dictionary is AEINRST, which spells 11 different seven letter words on its own. Look at what is in it: common letters, one S, a workable vowel-to-consonant balance. That is the shape to hold toward. When you are deciding what to keep after a play, keep the letters that look like that and dump the ones that do not.
Dump Early, Not Late
Across the whole corpus, the rarest letters by how many words contain them are W at 7 percent, Z at 4 percent, X at 3 percent, Q at 2 percent, J at 1 percent. The most common are E at 69 percent, S at 62 percent, I at 60 percent, A at 55 percent, R at 52 percent. A rack holding two of the rare group is a rack that will not bingo, so play them off early for whatever points they earn rather than holding them for a moment that never arrives.
Practising It
Put a rack into the Word Unscrambler and look at the seven letter group first rather than the biggest scorer. Doing that a few dozen times teaches the shapes faster than any list. The 360 richest letter sets are the same lesson in list form.
More like this in the guides index, or put your own letters into the Word Unscrambler.