New York Times, Thursday, December 12, 2013

This puzzle was a real challenge to construct, and I imagine it will be just as challenging to solve!

I originally came up with the idea in January after noticing that ERASERS becomes EASES after the Rs are literally erased. I wondered if there were any other words that made sense after their Rs were erased, particularly ones with multiple Rs. After that, I spent many hours trying to maximize the theme density, starting in the lower left with my favorite pair of entries, M(R) AND M(R)S. For the first time in many months, I had to use manual construction in conjunction with crossword construction software: I was able to create a word list with all the Rs filtered out to avoid adding nonthematic Rs, but I couldn't figure out a way to get the software to recognize that all entries crossing the thematic Rs had to make sense when the Rs were erased. Thus, the construction process, particularly in the upper half of the puzzle, was laborious—at multiple points, I was convinced that finishing this puzzle would be impossible. Yet somehow I managed to fill a grid that worked!

I wish I had been able to incorporate one more R in the upper right, but I just couldn't get it to work without seriously straining the fill. As a final note, I constructed the puzzle in a 72-word grid in case Will Shortz liked the theme but felt the puzzle would be more appropriate for a Saturday.

If I were selecting a Puzzle of the Week, this would probably be it. Both the theme idea and execution are beautiful. And most of the clues here are David's. I made the clues slightly easier than I usually would for a Thursday, because of the nastiness of the theme.

The puzzle is still probably pretty hard. Incidentally, the Monday-Thursday puzzles this week were used last Saturday at the 1st Arlington Heights (Ill.) Memorial Library Crossword Tournament. David's crossword, which was the playoff, is probably the first tournament puzzle ever in which empty squares in the solution were counted correct!

This puzzle is a thing of beauty. It took me a long time to realize what was going on — ERASERS is parsed as ERASE Rs — and when I cottoned to the trick, I marveled at the fact that the grid is so clean and sparkly, both with the Rs or without! It's rare I come upon a twist I've never seen before, and even more rare when it's this elegant. Bravo!

Note the extremely difficult constraint of creating a themeless (72 words) where all entries with Rs must also read normally with their Rs missing. Because of this, I expected there to be severe compromises in fill. And because the trick is so neat, I was prepared to be okay with some ugliness. I've tried something sort of similar (but easier) and found it near impossible. It caused me to break into tears in front of random people (sorry, dentist) and ultimately land on something that was too ugly to submit. That makes me appreciate this grid that much more.

True, there aren't that many marquee answers that you might see in a regular themeless — PAD THAI, AGES AGO, I SAY SO, M(R) AND M(R)S, SH(R)INE(R) is low for a straight themeless — but there also aren't many ugly bits that you typically see as "glue" to hold a themeless together. To have only TGI, SAE (self addressed envelope), and our friend ISAO Aoki, that's very good in terms of clean themeless fill. I've heard people grouse about Rapa NUI before (same with ULAN Bator) but I personally don't mind those at all. I like stories about those giant stone heads on Easter Island, and I think it's fun to know the name RAPA NUI.

The most minor of nits: I would have loved to see no cheater square after RELY (and the symmetrical one before COHN). I realize it must have made the fill cleaner, which I very much appreciate, but such a beautiful puzzle would have been even more visually elegant without the cheaters. A matter of personal opinion, that's all.

Standing O, David. Er, Mr. Steinberg. El Presidente. Save a job for me when you take over the world.