LONDON -- At the official launch party for the world's top eight players at the Houses of Parliament in London on Friday evening, Roger Federer joked he had been losing to everyone in practice.
Maybe he saw some truth in the quip.
If his first match at the ATP World Tour Finals is any indication, this could be a rough week for Federer as he seeks not only the championship here, but his 100th career title. Something is going to have to change in the next 48 hours.
On Sunday, Federer fell to Kei Nishikori 7-6 (4), 6-3 on the first day of round-robin play. Federer's game was unusually disjointed. He committed 34 unforced errors and he was tetchy, impatient and, quite simply, frustrated. He even received a code violation for banging the ball into the crowd.
This wasn't the match we could have anticipated, especially considering Federer had beaten Nishikori twice in the past month, first in Shanghai, and then, just over a week ago, in Paris.
"I felt we both struggled throughout the first set," Federer said in afterward, almost immediately after the match. "You could tell it was sort of a first round. I had my chances maybe a bit more than he did. Then I started to feel better in the second set. I think we both did. The level went up.
"Unfortunately, I couldn't keep the lead that I got early. That was important at the end. That was the key of the match, that 10-minute swing at the end of the first [set] to maybe 1-all in the second."
Federer could have won the first set; he created several chances on Nishikori's serve but never forced a break point. The tiebreaker was a horror show as Federer fell behind 6-1 before Nishikori eventually closed it out 7-4.
Even a break at the start of the second set didn't help Federer, who handed it back almost immediately. And from then on, he never looked capable of turning things around, something that is rarely said of the 20-time Grand Slam winner.
"I've been feeling fine," Federer said. "It's just that practice has been a bit all over the place. Practiced in Queen's [Club], practiced on the outside courts here, then center as well. So it's not always exactly the same conditions. Overall I thought I'm hitting the ball OK. Warm-up today was totally fine.
"I think maybe we both had a bit of nerves, too, not knowing how to attack second serve. It's OK now, now that the first match is out of the way."
Nishikori didn't play his best, either. But it will go down as one of his best wins, his first against Federer since 2014. Believe it or not, Nishikori wouldn't have even qualified for the event if not for injuries to Rafael Nadal and Juan Martin del Potro. Nishikori began 2018 by playing in two Challenger Tour events to find his confidence after a serious wrist injury.
For Federer, the round-robin format means he's still alive. It's not the first time he has lost his first match at the ATP Finals. In 2013, he fell in his opener and managed to reach the semifinals. It also happened in 2007 (and he came back to win the tournament) and '08.
But Federer is 37 now, and despite his success this season, he has struggled to produce his best tennis on a consistent basis. Federer went four months without a title, a drought that was eventually snapped last month in his hometown of Basel, Switzerland.
At the pre-tournament news conferences Friday, Federer said he was ready for one last push for the year. "I hope I don't go on vacation with three losses. Let's put it that way."
On Tuesday, Federer plays Thiem, who leads the Swiss 2-1 in their career head-to-heads. They haven't played since 2016.
"I just know I need to do better than today," Federer said. "That's pretty much it."
Pretty straightforward insight from Federer, but after Sunday's performance, straightforward seems pretty complicated.