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• The current puzzle 
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• A Nation-puzzle solver’s blog  where you can ask for and offer hints, and where every one of our clues is explained in detail.]
Ask a wordplay aficionado about the “Big Four” and it's possible they’ll know just what you’re talking about: J, Q, X, and Z, the four least commonly used letters in the English alphabet (or to put it another way, the four highest-scoring letters in Scrabble). These are the letters that lend spice and flavor to a crossword grid, keeping it from devolving into a blandly undistinguished mess of E’s and N’s and T’s and S’s.
But the culinary metaphor is a good one, because like spices the Big Four need to be used sparingly for maximum effect. Put too many of them in a grid and the result can be overbearing. The goal, ideally, is to sprinkle just enough unusual letters through a grid so that the solver is pleased by the overall effect without quite being aware why.
As in so many areas of life, the key is moderation, and this is even more true in cryptic crosswords than in standard crosswords, for a couple of reasons. For one thing, a cryptic crossword grid contains fewer letters—about 160, give or take, compared to as many as 190 in a standard crossword of the same dimensions—so distinctive letters stand out more piquantly.
But the more pressing difference is that a cryptic clue is much more sensitive than a standard clue to the particular letters in the word being clued. When it comes to Central American currency, for instance, the Guatemalan quetzal is no harder to clue in a standard crossword than a Nicaraguan peso (it’s much harder to get into the grid in the first place, but that’s another story).
Writing a cryptic clue for QUETZAL, on the other hand, is a headache. The big four letters resist all the usual cryptic techniques—they don’t play well with others in anagrams, they’re hard to disguise, they lend themselves to few obvious abbreviations, and so on.
So we’ve learned to keep them to a minimum. In fact, a look through our records shows that we’ve never yet included a word with more than one of the Big Four: no EQUINOX, no JACUZZI, no QUARTZITE. But here are a few entries we have used that would earn a high score in Scrabble:
AQUA VITAE Liquor with a drop of absinthe, as six eat up (4,5)
BANJOIST Prohibit support for Pete Seeger, e.g. (8)
EXPLOSIVE Volatile former pâtissier originally chopped olives (9)
LAZYBONES Idler is confused by zeal, son (9)
QUARTET Tauter “Dancing Queen” is foremost for ABBA, e.g. (7)
WOZNIAK Tech pioneer: “I know A-Z, but in a different order” (7)
Are there words or clues including the Big Four that you particularly like or dislike? Please share here, along with any quibbles, questions, kudos or complaints about the current puzzle  or any previous puzzle. To comment (and see other readers’ comments,) please click on this post’s title and scroll to the bottom of the resulting screen.