IF
Worth 5 points before any premium square, and the 12th highest-scoring of 96 — tied with 21 others.
IF extends into 4 three-letter words, which is the 11th least extendable of 96 — tied with 2 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
- K→KIF
- R→RIF
- F→IFF
- S→IFS
Not all of them are equally reachable, which a bare count of 4 hides. IF hooks on 4 distinct letters, and the ones you are likeliest to be holding are R (36% of opening racks), S (26% of opening racks) and F (14% 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 IF 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.