New York Times, Thursday, October 27, 2016

A few years ago, I wanted to make a puzzle where the solution involved leaving some squares blank. My original idea involved theme entries like "RUNNING ON [EMPTY]" and "[NOTHING] PERSONAL" where the Down answers only made sense if you left the bracketed words blank. But Will rejected a couple iterations of this, on the grounds that solvers wouldn't enjoy seeing a Down answer like "ASHG" (not knowing they were supposed to leave the G blank).

So the obvious next step was a puzzle where the Down answers worked as valid entries with OR without the letter from the intersecting theme entry, so solvers would see "BRAG" when the clue suggested BRA. I played with this a bit, but I eventually gave up on it — I couldn't "explain" the gimmick to my constructing software, and I was never much good at hand-filling.

Then, in 2013, my laptop got stolen and I didn't have a backup of my laboriously compiled crossword dictionary (may it rest in peace). I tried to start over, but I was back to square one — AARE and IS AT and INRI in every fill! I got discouraged, and stopped constructing ... until I graduated college last year, needed some supplemental income, and decided to get back in on that crossword cash.

I picked this "ghost" idea back up, since (lacking a good dictionary) I'd have to do some hand-filling anyway. I wrote a Python script to generate a list of answer pairs like HOLY LAND / HOLLAND to work with, and went from there. My submitted version didn't have the second half of the revealer clue (it was just "Riddled with ghosts") since I like the idea of a gimmick puzzle that has no indication anywhere that it's a gimmick puzzle — just clues and words. But I get that people would've had too much trouble without a revealer.

Some extra details for extreme crossword wonks: To fill this puzzle, I created a new dictionary with every possible answer pair encoded in a particular way. The pair BRA / BRAG, for instance, was included in the special dictionary as the word "BRAG1" — the numeral 1 after a letter indicates that that letter can be removed and still be an acceptable entry. Then I inputted the four theme answers as rebus squares, e.g. TOWNS as T1 O1 W1 N1 S1 (see here). This way, my filling software looked at "_ W1 _ _" and suggested words from the special dictionary: AW1OL (AWOL / AOL), GW1EN (GWEN / GEN), TW1IN (TWIN / TIN), etc. I still had to handpick entries where the longer answer stood on its own — without a clue — but this rebus trick was extremely helpful.

Neat concept, but difficult to explain. Four answers have "ghost" implied: (GHOST) TOWNS, (GHOST) WRITTEN, (GHOST) BUSTERS, and (GHOST) STORY. None of the letters in those words show up in the down answers, i.e. COUR(T)IER becomes COURIER. Finally, all the old words such as COURTIER are legitimate words (or word-ish).

Whew! Make sense? If not, I've done some highlighting in the grid below to try to make the principle clear. I've also fixed up the answers below so they match their respective clues.

I liked some of Milo's finds, HOL(Y) LAND to HOLLAND the standout. That's the type of discovery I marvel at, such a dramatic change — a colorful, long answer turning into another solid entry. COURTIER to COURIER is also good, but there's something about a two-word to one-word transmogrification that's so neat.

This type of construction feat is very difficult. I've done it once before, but it took so long to create that I doubt I'll do another like it. Milo has an even more difficult task, given how many ghosted letters he has to work with. It's especially difficult around those seven-letter entries — that's so many connected answers that have to be worked in!

Given the challenge, it's no surprise to see a few clunkers in the affected regions. I thought the NE suffered most, with IS WAR and MIN(T)ER, and the T BAR to BAR change isn't much a change at all. And as much as I loved HOL(Y) LAND to HOLLAND, having the awkward THR (from TH(O)R) took away from that region's appeal. There's also some awkward ASORT, RNDS, PRES spread around, not to mention CDI, ARD, AMU, etc.

Overall though, I liked the novelty of the ghosted words. Fun and tricky concept, appropriate for Halloween.