Beverage brand whose first mascot was Willy the Hillbilly / TUE 4-13-21 / Coyote outfoxer in cartoons / Part of San Diego that's home to its zoo / 1945 meeting place for FDR Churchill and Stalin

Constructor: Michael Lieberman

Relative difficulty: Easy-Medium

THEME: ROCKY START (59A: Bumpy beginning ... or a hint to 18-, 24-, 36- and 52-Across)— first words of themers can be preceded by "Rocky" in a familiar phrase or name:

Theme answers:

• ROADRUNNER (18A: Coyote outfoxer, in cartoons)
• HORROR FILM (24A: "Get Out," for one)
• MOUNTAIN DEW (36A: Beverage brand whose first mascot was Willy the Hillbilly)
• BALBOA PARK (52A: Part of San Diego that's home to its zoo)

Word of the Day: Martina Hingis (9A: Like Roger Federer and Martina Hingis = SWISS) —

Martina Hingis (German pronunciation: [marˈtiːna ˈhɪŋɡɪs]; born Martina Hingisová; 30 September 1980) is a Swiss former professional tennis player. She spent a total of 209 weeks as the singles world No. 1 and 90 weeks as doubles world No. 1, holding both No. 1 rankings simultaneously for 29 weeks. She won 5 Grand Slam singles titles, 13 Grand Slam women's doubles titles, winning a calendar-year doubles Grand Slam in 1998, and 7 Grand Slam mixed doubles titles; for a combined total of 25 major titles. In addition, she won the season-ending WTA Finals two times in singles and three times in doubles, an Olympic silver medal, and a record 17 Tier I singles titles.

Hingis set a series of "youngest-ever" records during the 1990s, including youngest-ever Grand Slam champion and youngest-ever world No. 1. Before ligament injuries in both ankles forced her to withdraw temporarily from professional tennis in early 2003, at the age of 22, she had won 40 singles titles and 36 doubles titles and, according to Forbes, was the highest-paid female athlete in the world for five consecutive years, 1997 to 2001. [...] 

Widely considered an all-time tennis great, Hingis was ranked by Tennis magazine in 2005 as the 8th-greatest female player of the preceding 40 years. She was named one of the "30 Legends of Women's Tennis: Past, Present and Future" by TIME in June 2011. In 2013, Hingis was elected into the International Tennis Hall of Fame, and was appointed two years later the organization's first ever Global Ambassador. (wikipedia)

First of all, Rocky Raccoon. Where is my RACCOON answer!? I realize that there aren't many good phrases beginning RACCOON, but, I dunno, make RACCOON TAIL work somehow. In fact, take out MOUNTAIN DEW, which is a fine answer but which works Horribly with the theme (a single Rocky Mountain?) and replace it with RACCOON TAIL (or Raccoon some-other-four-letter-word). Rocky in, single "Mountain" out, two birds, one stone. That would have given the theme a somewhat more elegant and amusing expression. But it wouldn't have improved things that much, because at its heart this is a pretty dull-ish 20-years-ago-ish first-words-type theme. Yes, those phrases all "start" with words that can be preceded by "Rocky." But only BALBOA PARK is all that interesting / original. You could do this again and have the phrases start with different things that are known as "rocks" (like, I dunno, ICE, DIAMOND, whatever); or words meaning "rock" (STONE, BOULDER) or whatever. Something that made the "Rocky" in ROCKY START more punny and wacky. This was just programmatic. It was also such a let-down when the first themer I got was HORROR FILM with Jordan PEELE on top ... and then the rest of the themers were not somehow also directors sitting on top of their movie's genres. I was like "Oooh, PEELE over HORROR FILM, I wonder what the theme revealer phrase is going to be, this should be good." And then it wasn't. Not so much.