In a private communication I recently received an example and a challenge. The example was to change COLD to BARE by changing each letter in turn (all words to be valid), then to return to COLD in the same fashion: COLD BOLD BALD BARD BARE CARE CORE COLE COLD. I have previously called such sequences of there-and-back (regardless of the order of change) Snakes and Ladders, so I termed these sequences Sequential Snakes and Ladders, or SSLs for short.
"Sequential Snakes and Ladders,"
Word Ways: Vol. 33
, Article 4.
Available at: http://digitalcommons.butler.edu/wordways/vol33/iss2/4