Given the 26 letters in the alphabet, the midpoint lies between the 13th and 14th letters, M and N, Imagine a process which can take a word and each of its letters and transform the words into a different string of letters, such that the letter A is changed to a Z, the letter B is changed to a Y, a C to an X, and so on, with M being changed to an N. Here, the midpoint of the alphabet acts like the fulcrum of balance, with the original word and the transformed string of letters pivoted equally. As an example, take the word JOLLY; this transforms to the meaningless sequence QLOOB.
"Balanced Word Pairs,"
Word Ways: Vol. 37
, Article 16.
Available at: http://digitalcommons.butler.edu/wordways/vol37/iss4/16