Performer's grand slam in modern parlance / THU 9-30-21 / Calif school that's about 20 miles from the Mexican border / Major Chinese internet company / Pregnancy hormone / Acqua cause of annual flooding in Venice

Constructor: Rich Proulx

Relative difficulty: Medium

THEME: SOUND MIXING (57A: Academy Awards category eliminated in 2021 ... or a hint to interpreting four clues in this puzzle) — familiar two-word (or two-part) phrases clued as the "mixing" of two "sounds," i.e. as equations following this pattern: [sound] + [sound] = [regular clue]:

Theme answers:

• TWITTER BUZZ (17A: [Birds] + [Bees] = P.R. campaign goal)
• HUMDRUM (26A: [Lightsaber] + [Impatient fingers] = Boring)
• RING POP (36A: [Cellphone] + [Bubble] = Edible accessory)
• LOW ROLL (48A: [Cow] + [Thunder] = Snake eyes, e.g.)

Word of the Day: RELAXIN (44D: Pregnancy hormone) —

Relaxin is a protein hormone of about 6000 Da first described in 1926 by Frederick Hisaw. ["Da" = Dalton, "a unit used in expressing the molecular weight of proteins, equivalent to atomic mass unit."]

The relaxin-like peptide family belongs in the insulin superfamily and consists of 7 peptides of high structural but low sequence similarity; relaxin-1 (RLN1), 2 (RLN2) and 3 (RLN3), and the insulin-like (INSL) peptides, INSL3, INSL4, INSL5 and INSL6. The functions of relaxin-3, INSL4, INSL5, and INSL6 remain uncharacterised. [...] In the female, it is produced by the corpus luteum of the ovary, the breast and, during pregnancy, also by the placenta, chorion, and decidua.

In the male, it is produced in the prostate and is present in human semen. (wikipedia)

• • •

So you're telling me MOOROLL is not a thing?

I didn't know SOUND MIXING was an Academy Award to begin with, so the MIXING part was weirdly hard for me to get at the end. I had DESIGN in there at first. Then tried to cram in EDITING. But MIXING much better expresses the whole sound equation thing happening in the theme clues today, which I think basically works—that is, these themers are all phrases made out of the combination ("mixing") of two sounds. The equation gimmick is clever, even if the themers do end up essentially double-clued. I can imagine the theme clues being written with the first part dropped entirely, such that the revealer would cause you to look back and notice, "oh, right, those are indeed two sounds mixed together," but I think it's more fun to have the weird sound equation thing going on. It puts the theme into the mix, allowing it to be visible and relevant to the solve throughout the puzzle instead of just something you notice at the end. It makes the theme a lot easier to crack than usual, but the difficult-ish cluing overall, as well as two terms I've never seen in my life, made the overall solving experience reasonably Thursday-ish in the end. 

Not only had I never heard of BAIDU (12D: Major Chinese internet company) or RELAXIN, I had no way of inferring any part of those answers, any single letter, and so working the crosses was really harrowing. If even one went wrong, or was at all ambiguous, I was going to be in a hell of a lot of trouble. As for the BAIDU crosses, the only one that seems at all potentially problematic is ABE—maybe you aren't familiar with old NYC mayors—but I don't know what else the name could be with an A_E pattern. Doubtful any mayor was ever named ACE or AXE. As for RELAXIN, the weak link there is SNERT—a familiar bit of crosswordese to anyone who's been solving the puzzle since the 20th century, but not exactly a name that is current or *at all* inferrable. I can definitely see the Hagar the Horrible-ignorant among us going for some different letter in the "N"'s place ... though I can't really imagine what that letter would be. Looks like -IN is the most common hormone name ending, so maybe the "N" was more inferrable than I thought. Anyway, I got everything right. BAIDU and RELAXIN were just completely new to me, and particularly hard to get (not surprisingly, neither one has ever been an entry in the NYTXW before).

The fill is a little rough in places. The whole NW and N is kind of a wreck (ALTA ADMIN ANNO + ASSOC USBS LSU all abbrev-clustered together there). OXES is a pretty awful stretch (34D: Dumb ___ (buffoons)). AS A PIN is bottom-of-the-barrel stuff, even (especially?) with the cutesy "?" clue (24A: Neat analogy?). I have heard of data mining, but never thought of a single DATA MINER as a thing (I'm imagining someone at their keyboard with overalls and a little lamp helmet on). My only complaint there is that I think of data mining as much more nefarious / surveillance-y than simply "searching for patterns in the statistical noise," so the answer itself bums me out a little. I would normally be very bummed out by LIZ Cheney as well, but since she's vociferously anti-Trump (and anti-Trumpist), I'm gonna let her pass. I wrote her in first as LYN, but that's her mom (spelled "Lynne"). I guess "DO" is duped in "YES I DO" and UPDO, but I really DO not care. Really liked COZY UP TO and "I'M ALL OUT" . This feels like the first puzzle I've (mostly) liked in a while. A harbinger of a good weekend ahead (I'm choosing to believe).

Signed, Rex Parker, King of CrossWorld

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