My wife and I enjoy playing hangman when we go out to eat. Over the past decade she’s caught on to ETAOIN SHRDLU (as I first learned from GEB), and now picks some truly bizarre phrases.
Oh yes. Hangman got a lot easier once I learned touch-typing on a keyboard layout that puts common letters on the home row. I started being able to solve a lot of those puzzles really quickly by simply reciting the home row (ARSTD HNEIO). Unlike your wife, my friends never figured out how I did it (!).
Just today I spotted my 8 year old nephew writing ciphertext, using two substitution ciphers (alternating with each letter). I told him I could write code to decrypt his ciphertext automatically- and did. He was suitably impressed. I enjoyed showing him Elixir - he has only seen Scratch before.
Three seconds later though, he wanted me to do it without access to the substitutions he’d written down. Luckily for me, I did this a few years back using letter frequencies and - I think - a wordlist. Unluckily for me, he’d only written three words, and had purposely included few ‘e’s. I had to explain that unfortunately I had no chance unless he wrote more!
There are, unless I’m mistaken, 26^2=676 possible ciphers with that scheme – sounds like something you should be able to crack by simply trying all of them and checking with /usr/share/dict/words to see when you get it right!