ES
Worth 2 points before any premium square, and the lowest-scoring of the 96 — tied with 35 others.
ES extends into 6 three-letter words, which is the 18th least 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
- H→HES
- O→OES
- P→PES
- R→RES
- Y→YES
- S→ESS
Not all of them are equally reachable, which a bare count of 6 hides. ES hooks on 6 distinct letters, and the ones you are likeliest to be holding are O (45% of opening racks), R (36% of opening racks) and S (26% of opening racks). The rarest is Y, at 14%.
How often you can actually play it
Out of an opening rack, 14.18% of the time you hold the letters for ES outright, the 21st likeliest of 96 — tied with 3 others. Counting a blank as whichever letter is missing lifts that to 21.86%, 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.