ab and ba tie for the highest Scrabble score from ab at 4 points. The top 2 of 2 words are shown here, with the full list organized by length below.
There are 2 two-letter words hiding in ab: one comes from rearranging its letters, and ab itself is already a playable word with no unscrambling required. No common everyday answer stands out among these two-letter results, so let the score decide: the highest-scoring words are ab and ba, each worth 4 points in Scrabble.
The full list follows, sorted A to Z; every score reflects tile constraints and skips board bonuses.
ab 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.
Dictionaries record four senses for ab. Scrabble and Words With Friends score tiles and not meanings, so every sense below is worth the same 4 points on a Scrabble board:
ab is one of two two-letter words the same letters produce. No arrangement of the same tiles scores higher in Scrabble, so playing ab unchanged also takes the maximum points these letters offer.
The highest-scoring plays from these letters are ab and ba, worth 4 points in Scrabble, and nothing else built from ab 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 ab produce 2 valid words in the Scrabble and Words With Friends dictionaries. The word count by length is: 2 two-letter words.