In 1879, Lewis Carroll (who wrote Alice in Wonderland) devised a “verbal torture” to amuse two young ladies.
Carroll called this puzzle doublets. This is how a doublets puzzle works: You start with two words, both with the same number of letters. You link these two words by interposing other words, each of which differing from the previous word by one letter only. You begin by changing one letter in the first word to create a new word. You repeat this process, changing one letter at a time and creating new words, until you end up with the second word.
Here's an example from Lewis Carroll that transforms APE to MAN:
APE
ARE
ERE
ERR
EAR
MAR
MAN
This solution uses five intermediate words to transfer APE to MAN. Here's a better solution that uses just four words to accomplish the same transformation:
APE
APT
OPT
OAT
MAT
MAN
Here's another example, this time with four-letter words. The challenge is to transform CARD to GAME.
Here is the solution:
CARD
CARE
CAME
GAME
Your turn now! Here are 10 doublets for you to solve:
BALL to GAME
BLACK to WHITE
HEAD to TAIL
CAT to DOG
DOWN to SIZE
FOUR to FIVE
MORE to LESS
GRASS to GREEN
TEAM to WORK
WORK to PLAY
Remember there could be several different acceptable solutions.