Jack Sock might be the most surprising last-minute qualifier in the history of the ATP Finals. The American was ranked No. 24 heading into Paris, but everything fell into place with other contenders dropping and Sock left as the last man standing. 

The new No. 9 was drawn into the Boris Becker Group, and faced Federer in his opening match on Sunday. Proving to be no easy task, Sock lost 6-4, 7-6 (4). He still has Marin Cilic and Alexander Zverev to play. 

2017 Season

  • 36-19 record
  • 3 titles (Auckland, Delray Beach and Paris)

Best Performance

Sock became only the third player born in the 1990s to win an ATP Masters 1000 title and the first American to win one since Andy Roddick at the 2010 Miami Open. 

Season Low

After a strong start to 2017, Sock’s play began to dip after Miami, and Jordan Thompson proved fatal in two big matches. He defeated Sock in the opening Davis Cup tie, which doomed the Americans. In the late summer, Thompson pulled out a five-set victory in the first round of the US Open, not exactly the performance Sock was hoping for in the biggest tournament in his home country.

"I mean, utter disappointment when you're up two breaks in one (second) set, a break in the fifth," Sock said. "Choke it all the way. Really sucks."

Best Social Media Moment

After winning his first-round match at Wimbledon, Sock flipped a towel in the direction of a young fan. Unfortunately, the towel was ripped away by a fully grown man. Later, Sock used social media to track down the boy and repair the injustice. 

Best Quote

Sock narrowly lost a hotly contested match to Rafael Nadal at the Laver Cup, but approved of captain John McEnroe’s fiery speeches and intensity. Sock told the Telegraph

“I think the guys on our team actually feed off [McEnroe's coaching style] as well. You listen to an NBA game, if they were mic'd up, you hear some things from coaches, players. Same in the NFL and a lot of other sports. A lot of people think tennis needs to be one way, but it's sport, it's entertainment.”