The puzzle’s title, “Nine of Diamonds,” might also have been “Batter Up!” since it refers to baseball and not card games, which I thought might be a possibility. However, once I realized that it was a baseball theme (very appropriate title*), and I had enough letters filled in for each of the nine clues, completing those answers was easy breezy since I have been a Yankees fan my entire life and am totally familiar with baseball terminology.
23A: Cuts in a cardboard container? (BOX SCORES)
31A: Yelled initially? (CALLED OUT AT FIRST)
44A: So-so formal dance? (FAIR BALL)
46A: Went far too slowly during the 10K? (WALKED IN A RUN)
63A: Piece of black-market playground equipment (SWING FOR THE FENCES)
83A: Wool or cotton purchase request? (BATTING ORDER)
85A: Disgusting advice? (FOUL TIPS)
98A: Whiskey bottle dregs? (BOTTOM OF THE FIFTH)
113A: Nobleman after a banquet? (FULL COUNT)
At the end, an error-free completed puzzle came down to one section. I had no idea what the answer was to 21 Across: Mountain ridge. Nor to two clues that bisected it, 10 Down: Prayer and 13 Down: Orphan girl in Byron’s “Don Juan.” For 21 Across, I had AR_T_. That meant one open space for each of the Down clues. I guessed ARETE, which turned out to be correct. So, the answers to 10 and 13 Down are ORISON and LEILA, respectively.
Puzzle completed. A Home Run!
*For anyone not familiar with baseball, there are nine players on each team’s line-up, and the infield is called the diamond since the bases are arranged in a diamond shape with the pitcher’s mound in the center.