Federer's excellence, Serena's future and more March takeaways

Federer neutralizes Isner to win Miami Open (1:46)

Roger Federer defeats John Isner in straight sets to win his fourth Miami Open and 101st overall career title. (1:46)

The "Sunshine Double" -- the back-to-back Indian Wells and Miami Open tournaments that basically span the entire month of March -- is in the rearview mirror now, and both the ATP and WTA turn their eyes east, toward the upcoming European clay-court season.

Here are six takeaways from a March that was sometimes windy, cold and wet -- and always unpredictable.

Djokovic is No. 1, but Federer is the gold standard

Novak Djokovic emerged from his post-Australian Open break seemingly ready to resume his domination of the ATP Tour. He had previously completed a Sunshine Double hat trick (winning both Indian Wells and Miami from 2014-16) and swept the three most recent Grand Slam events. But he admitted he wasn't well prepared for the month and, as head of the Player Council, had spent considerable time working on ATP politics (more on that later). Djokovic stumbled out of Indian Wells in the third round (he had a first-round bye) and was stunned in Miami in the fourth round by Roberto Bautista Agut.

When Djokovic met with the press following the latter defeat, he denied that the extra-tournament demands on his time were to blame, but by the end of the news conference he admitted, "[I had] way too many things off the court. I guess that affected me a little bit on the court."

Meanwhile, Roger Federer rolled into Indian Wells with a No. 4 ranking and set to work. He had an excellent tournament but took a loss in the final to No. 7 seed Dominic Thiem. The loss motivated Federer to play brilliantly in Miami, where he had to outfox two rapidly rising young stars (Daniil Medvedev and Denis Shapovalov) and survive two of the most fearsome servers in the game -- Kevin Anderson and, in the final, John Isner.

Thus, Federer became the year's first two-time winner on either the ATP or WTA tours after 32 combined tournaments in 2019. "I guess it's kind of fitting," Isner said. "He's one of our current greats and, of course, all-time greats."

Serena Williams' future is unclear

The Williams sisters still officially reside in Palm Beach Gardens, Florida. The Miami tournament has always been their home court. Both have won it, with Serena collecting eight trophies. Not this year, though, and you have to wonder what the future will bring.

Serena trailed No. 20 seed Garbine Muguruza by a set and 1-0 when she retired from their third-round Indian Wells match with an unspecified viral illness. In Miami, she was pushed to three sets in her first match and withdrew from the tournament before her third-round meeting with No. 18 seed Qiang Wang. The tournament made the announcement in a press release that quoted Williams, who cited a knee injury, but provided no details about the nature of the injury, its severity, or how and when it had occurred. Williams has retired from two of the three events she has played this year.

Back in 2015, Williams' bid for a calendar-year Grand Slam was halted in a dramatic upset by heavy underdog Roberta Vinci in the semifinals of the US Open. Williams ended her 2015 season with that match. At that time, her coach, Patrick Mouratoglou, told Britain's The Telegraph: "The cartilage [in her knees] is not gone, not all of it, but a big part." Mouratoglou said in Miami that Williams will play next in mid-May at the Italian Open, which begins two weeks before the French Open. Last year, Williams withdrew from the French Open before her fourth-round meeting with Maria Sharapova due to a pectoral injury.

The ATP's Next Generation has arrived

All the hype the ATP has whipped up with its #NextGenATP campaign has been justified. By the end of March, three frontrunners had emerged from the impressive fleet of rising stars: 20-year-old Stefanos Tsitsipas, who moved up to No. 8 on Monday, and Canadian teenagers Felix Auger-Aliassime, 18, and Shapovalov, 19.

Auger-Aliassime reached the third round and Shapovalov the fourth round at Indian Wells, and both belted their way to the semifinals in Miami. Shapovalov knocked off Tsitsipas via a third-set tiebreaker in their fourth-round battle in Miami, then eliminated another Next Gen standout, Frances Tiafoe, before Roger Federer dispatched him in the semis.

Auger-Aliassime and Shapovalov may be creating the premier fraternal rivalry of the next decade. As Shapovalov said of his countryman in Miami: "This week, every time I see him win, I'm like, 'Come on, you know, let me try to win as well and see how far we can get together. It's just a healthy thing we have had since juniors. ... We're always constantly competing. I think it's just so great for us and so great for the country."

The WTA is wide, wide open

The most riveting story in March was the emergence of 18-year-old Canadian Bianca Andreescu, who became the first wild-card entrant to win Indian Wells. She was also the 13th different woman to win a tournament this year. While the men could not keep their one-title streak going in Miami as a result of Federer's second title of 2019, the women did, thanks to champion Ashleigh Barty.

There was plenty of reason to suspect that a high-value name -- a Naomi Osaka, Serena Williams or Petra Kvitova -- might not take either of those titles, but who could have predicted this outcome?

Andreescu backed up her Indian Wells title with an excellent run in Miami, beating No. 8 seed Angelique Kerber for the second time in just over a week before retiring down a set in her fourth-round match due to a shoulder injury. Barty, meanwhile, wrote one of the great feel-good stories in Florida, capping her difficult, complicated journey from burned-out prodigy to Miami champion and new resident of the top 10.

All the winners of hard-court WTA tournaments so far this year have been 22 or under, leading 27-year-old Karolina Pliskova, whom Barty beat in the Miami Open finals, to say: "I think they are going for it. They don't have the pressure which maybe the other players have."

The ATP is in the throes of a potential rebellion

Chris Kermode, president of the ATP, had an even worse week than Djokovic at Indian Wells. He learned that the organization he has headed so successfully would not grant him a third three-year term, despite the gains the ATP has made in various areas, including increased prize money. This was essentially a palace coup engineered by player representatives on the ATP board of directors -- with help from the ATP Player Council and its president, Djokovic.

This is a populist rebellion, with the rank and file wanting a greater share of tournament revenues and bigger paychecks for lower-ranked players. Those players were convinced that Kermode, who casts the tie-breaking vote on the ATP board, favored the interests of the tournaments over those of the players. To complicate things, Federer, Rafael Nadal, Stan Wawrinka and others have been outspoken supporters of Kermode.

Given that the ATP Tour is actually a partnership between the players and the tournaments, this could get ugly.

The U.S. women are in need of a reset

It seems like ages ago now, but in 2017, all four US Open women's semifinalists were homegrown: eventual champion Sloane Stephens, as well as Madison Keys, Venus Williams and CoCo Vandeweghe.

It's been almost all downhill since then, although Stephens did win Miami and played in the French Open final in 2018. Ranked No. 1 not long ago, Stephens is down to No. 8. Meanwhile, Serena Williams is out of the top 10, at No. 11, and 38-year-old Venus Williams is ranked No. 48. Keys is spinning her wheels at No. 18, and Vandeweghe is 8-14 over the past year. Vandeweghe clocks in at No. 115 and has yet to swing a racket this year due to a foot injury.

The best U.S. female performer in March? Venus Williams was the only American woman to get as far as the fourth round at either event, and she did it in both tournaments.