The Numberplay blog on the NY Times website used to have word ladder puzzles along with their weekly math puzzles. I found them fun and so I figured I'd introduce them here. These aren't just your basic word ladders either.

1. You can change a single letter in place, as in traditional word ladders — for example, SOAP to SOUP.
2. You can add or subtract a single letter in place to increase or decrease the length of a word — for example, MATH to MATCH or vice versa.
3. You can change a single letter and rearrange the letters of the word to give another word of the same length — for example, MUSEUM to SUMMED (with a U changed to D and then rearrangement).

The aim is to make the shortest possible ladder. All steps must be valid English words. You can use the Enable list for a comprehensive list of words.

Here's an example:

CIRCLE to SQUARE

CIRCLE
RELICS
CRUISE
SAUCER
SQUARE

Now try these:

WOLVES to SHEEP
NUMBER to PATTERN

Just for fun, here are the two words that are furthest apart and the ladder between them:

gametophytes , gametophyte (-s), hepatectomy (g -> c), hypothecate (m -> h), hypothecated (+d), tracheophyte (d -> r), phreatophyte (c -> p), phreatophytes (+s), phanerophytes (t -> n), nephropathies (y -> i), ethnographies (p -> g), stenographies (h -> s), atherogenesis (p -> e), teratogenesis (h -> t), antiestrogens (e -> n), antiestrogen (-s), nitrogenases (t -> s), reassignment (o -> m), mastersinger (n -> r), streamliners (g -> l), masterliness (r -> s), essentialism (r -> i), timelinesses (a -> e), timelessness (i -> s), silentnesses (m -> n), tonelessness (i -> o), solemnnesses (t -> m), movelessness (n -> v), lovelessness (m -> l), lovelinesses (s -> i), slovenliness (e -> n), lovingnesses (l -> g), livingnesses (o -> i), kinglinesses (v -> k), slinkinesses (g -> s), sicklinesses (n -> c), stickinesses (l -> t), trickinesses (s -> r), trickishness (e -> h), ticklishness (r -> l), singlesticks (h -> g), singlestick (-s)

• This would be very cool for code golf/programming puzzles. Would you be offended if I propose a challenge for a solver there on the meta question? Would you like to? – kaine Oct 17 '14 at 14:36
• @kaine Go for it. – Golden Dragon Oct 17 '14 at 14:37
• Should try golf to club. – warspyking Oct 17 '14 at 22:51
• I'd imagine you could do this with pretty much any words. – warspyking Oct 17 '14 at 22:51
• @warspyking Indeed you could! Going with the enable list again, not all words are connected. There are a bunch of small sets of words that are connected, and there is also a set of 132313 words that are all connected. – Golden Dragon Oct 20 '14 at 12:27

• wolves shovel shove hopes sheep

• number bunter banter batter patter pattern

The second answer seems to be baseball themed.

Old:

wolves solved solve slope sleep sheep

Edit: as was pointed out by @Golden, Wolves can be done slightly quicker:

• Good job, but WOLVES to SHEEP can be solved in one fewer steps! – Golden Dragon Oct 17 '14 at 14:11