This week on Tennis.com, we're featuring five storylines—one a day—that came out of the ATP and WTA's year-end rankings.
So far, we've covered how this is the first time since 2004 that four American women finished a year inside the Top 10, Novak Djokovic becoming the oldest player to finish a year inside the Top 4 in ATP rankings history, Lorenzo Musetti single-handedly keeping the one-handed backhand year-end Top 10 streak alive, and Coco Gauff becoming the youngest woman this century to finish in the Top 3 for three straight years.
Today, a rare level of dominance from a dynamic duo...
