plank needs no unscrambling at all — the five-letter word is already the strongest play its own letters allow, banking 11 points in Scrabble as it stands. In all, 16 valid words come out of this rack, grouped by length below and checked for Words With Friends as well as Scrabble.
Unscramble KLPAN, NAPKL or KNAPL and you get the same 5 letters as PLANK: so the words from PLANK listed below are the words from those scrambles too.
plank is the highest-scoring word from plank, worth 11 points in Scrabble. The top 10 of 16 words are shown here, with the full list organized by length below.
Only one five-letter word uses the letters in plank — and it is plank itself. No unscrambling is needed: the word is already playable as written, worth 11 points in Scrabble.
1 six-letter word can be made using all the letters in plank plus one additional letter.
Swap a single tile in plank and you get a different five-letter rack with its own word list. None of these appear in the results above — they share 4 of the 5 letters, not all of them.
plank 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 3-point gap between the two totals comes from the tile values themselves: Scrabble and Words With Friends price the same letters differently.
Dictionaries record five senses for plank. Scrabble and Words With Friends score tiles and not meanings, so every sense below is worth the same 11 points on a Scrabble board:
plank is the only five-letter word the same letters produce. No arrangement of the same tiles scores higher in Scrabble, so playing plank unchanged also takes the maximum points these letters offer.
The highest-scoring play from these letters is plank, worth 11 points in Scrabble, and no other word from plank 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 plank produce 16 valid words in the Scrabble and Words With Friends dictionaries. The word count by length is: 1 five-letter word, 3 four-letter words, 6 three-letter words and 6 two-letter words.