itch.io

concur: without the restricted wordlist and in hard mode, it does feel like locking in a letter hurts a lot; many of the popularised starts can easily get trapped after the first guess:

 * SIREN gets trapped by [B/C/D/F/K/L/M/N/P/S/T/V/W]INES

 * AROSE/SOARE gets trapped by RA[C/G/J/K/L/P/T/V/X/Z]ES (and maybe RARES/RASES) as well as S[C/E/H/N/P/T/W]ARE

 * SALET gets trapped by [D/F/H/M/P/R/V/W/Z]EALS (but not TEALS or SEALS)

 * ORATE/ROATE gets trapped by TA[B/K/L/M/P/S/V/W/X]ER (and maybe TATER)

most, if not all, of the "best strategy" presentations depend on the reduced solution list to avoid corridor traps ([B/D/E/F/H/L/M/N/R/S/T/W]IGHT is reduced to [E/F/L/M/N/R/S/T/W]IGHT for example; also almost all S-terminal plurals and present verbs are not on the list).  given that, by an exhaustive search posted by Alex Selby, the best word averages 3.42 guesses and the worst word averages 4.10 guesses (in normal mode), it's probably more important not to fall into any traps while discovering information on hard mode, since the worst average has 1.90 guesses to spare (noting though that the worst guess ends up falling back to the 'optimal' guess in half the cases, and fails to guess the word some of the time).

from the human side of things, digraphs probably do play a significant role in making guesses; if R, H, T, S, L, and N are all ruled out, for example, you can be fairly certain the word has at least two vowels, without having to guess the vowels and restricting further guesses.

it doesn't feel like a binary search is optimal in hardmode, since confirmation reduces the ability to get more information, unless the search space is sufficiently small (which is true with the restricted word list, but not as much with the full word list)

(personally, CRWTH is my starter of choice, followed with confirmed letters with S+L+P / S+L+N / S+N+D)

I absolutely agree that you have a good point if we're talking about hard mode! In hard mode finding letters is not only the goal of the game, but also something that hinders you in achieving that goal. So finding common letters later can clearly be an advantage then, especially if the strategy you're running is to set aside some number of guesses at the start for letter-hunting.

This is just by my gut feeling, but In English it feels finding  vowels is less helpful for narrowing down what letters can go next to it than finding a consonant, and especially an uncommon consonant. The only languages I really know are Swedish, English, and JavaScript, but it feels like the irregular spelling  of words in English vs their sounds mean that vowels can go anywhere they damn please given just one or two other fixed (green) letters around them. Whereas consonants following each other can do weird things on occasion, but if you have a word starting with T you know that if it's not a vowel coming up, it's pretty much for sure is going to be H, R or W. T's in the middle of a word add C and another T as other common possibilities. But for vowels, loan words with spellings from languages that treat vowels differently mean that such rules for are much fewer and much more frequently broken. Very often when I get stumped trying to figure out what word could possibly fit with just one unknown and four greens, the reason is that I overlooked the word is because I pronounced it wrong when I checked the possibilities. This is less of an issue (but can still happen) when I play word games in Swedish, and I don't think it's mainly because it's my first language; having had a spelling reform, even if it was in 1906, means that Swedish is a bit more regular in how it uses its vowels.