AY
Worth 5 points before any premium square, and the 12th highest-scoring of 96 — tied with 21 others.
AY extends into 18 three-letter words, which is the 4th most extendable of 96 — tied with 3 others. That is the number worth memorising: a two-letter word is a place to put tiles, but a well-hooked one is a place to put them where the board stays open.
Every hook
- B→BAY
- C→CAY
- D→DAY
- F→FAY
- G→GAY
- H→HAY
- J→JAY
- K→KAY
- L→LAY
- M→MAY
- N→NAY
- P→PAY
- R→RAY
- S→SAY
- W→WAY
- Y→YAY
- E→AYE
- S→AYS
Not all of them are equally reachable, which a bare count of 18 hides. AY hooks on 17 distinct letters, and the ones you are likeliest to be holding are E (60% of opening racks), N (36% of opening racks) and R (36% of opening racks). The rarest is K, at 7%.
How often you can actually play it
Out of an opening rack, 6.06% of the time you hold the letters for AY outright, the 44th least likely of 96 — tied with 15 others. Counting a blank as whichever letter is missing lifts that to 12.69%, though spending one of the two blanks on a two-letter word is rarely the play. Exact hypergeometrics over the 100-tile bag, not a simulation.
It reverses
AY backwards is YA, which is also good. That is how most of this list is actually learned — 46 of the 96 come in reversible pairs, so knowing one gets you the other free.