I have a hard time understanding how you can use the 'hard' method in which you must include all 'found' letters in your next guess. Won't a word with many possible letters cause you to run out of chances?

For instance, in yesterday's effort, I had to come up with a word that included alternative letters so as to eliminate possibilities, at the same time as testing if one of the letters was used more than once.

Hope this makes sense without giving anything away.
Yesterday, 5.
Today, 4.