yaff needs no unscrambling at all — the four-letter word is already the strongest play its own letters allow, banking 13 points in Scrabble as it stands. In all, 6 valid words come out of this rack, grouped by length below and checked for Words With Friends as well as Scrabble.
yaff is the highest-scoring word from yaff, worth 13 points in Scrabble. The top 6 of 6 words are shown here, with the full list organized by length below.
Only one four-letter word uses the letters in yaff — and it is yaff itself. No unscrambling is needed: the word is already playable as written, worth 13 points in Scrabble.
Swap a single tile in yaff and you get a different four-letter rack with its own word list. None of these appear in the results above — they share 3 of the 4 letters, not all of them.
yaff is in the NWL, the official Scrabble word list for North America, and in the Words With Friends dictionary, so it's playable exactly as it stands and needs no unscrambling.
The 1-point gap between the two totals comes from the tile values themselves: Scrabble and Words With Friends price the same letters differently.
yaff is the only four-letter word the same letters produce. No arrangement of the same tiles scores higher in Scrabble, so playing yaff unchanged also takes the maximum points these letters offer.
The highest-scoring play from these letters is yaff, worth 13 points in Scrabble, and no other word from yaff earns more points in Scrabble. Words With Friends prices the same letters differently, so the top of the list changes on a Words With Friends board. Both scores count tile values only and exclude premium squares.
The letters in yaff produce 6 valid words in the Scrabble and Words With Friends dictionaries. The word count by length is: 1 four-letter word, 2 three-letter words and 3 two-letter words.