Best Word Ladders
25th June 2020
I've recently been working on improving the word games on Pencil and Paper Games, and while testing Word Ladders I happened to get a particularly hard ladder; you might like to try it:
Theoretically, the shortest possible ladder with four-letter words, and no matching letters, is 5 steps. How close can you get to this?
Hardest four-letter ladder
After finding this ladder I wondered whether I could search for the hardest possible four-letter ladder; in other words, the pair of words that requires the largest number of steps. My first attempt at writing a program to do this, using the PAPG word database, was going to take something like 4000 hours to check all possible ladders, which didn't seem feasible.
After making a few assumptions to reduce the number of words I was testing I managed to get this down to under an hour.
Here's the nicest maximal word ladder I found:
If only AMEW or ANEN were valid words it would be possible to solve this in a three-step ladder. I warn you: this is a hard one! However, none of the words in the ladder are obscure.
Hardest three-letter ladder
If you want to warm up on something a lot easier, here's one of the longest word ladders I found with three-letter words:
Here are the answers:
anew to amen – 17 steps:
anew knew know snow show shod shed seed deed dyed dyes eyes eves even oven omen amen
ivy to end – 8 steps:
ivy icy ice ace act ant and end