Constructor: Jeffrey Martinovic and Will NedigerRelative difficulty: EasyTHEME: RSVPING (60A: Acknowledging and invitation ... or a hint to the starts of 19-, 32-, 39- and 49-Across)— the letters R, S, V and P precede "-ING" in the first word of each theme answer; so the puzzle itself is RSVPING, in a way; it's "R"ing, then it's "S"ing, then it's "V"ing, then it's "P"ing ... (!)Theme answers:RING ANNOUNCER (19A: "And in this corner..." speaker)SING BACK-UP (32A: Use non-lead pipes?)VING RHAMES (39A: Actor who plays Luther Stickell in the "Mission: Impossible" franchise)PING-PONG BALLS (49A: Projectiles tossed into cups of beer, in a drinking game)Word of the Day: Beer pong(the "drinking game" in the clue for PING-PONG BALLS) —Beer pong, also known asBeirut, is adrinking gamein which players throw aping pongball across a table with the intent of landing the ball in a cup ofbeeron the other end. The game typically consists of opposing teams of two or more players per side with 6 or 10 cu...