It’s three down, one to go. The US Open is the year’s sole remaining Grand Slam, meaning the world’s best have one last chance to put their stamp on the 2016 season.

Before the road to the 2016 US Open begins with this summer’s Emirates Airline US Open Series, let’s take a look back at what we’ve learned from the recently completed gauntlet through the French Open’s red clay and Wimbledon’s manicured lawns:

Djokovic and Serena may be beatable after all, but they’re still your US Open favorites: Novak Djokovic’s loss to Sam Querrey in the third round of Wimbledon was the year’s most stunning result – and Serena Williams’ losses in the Australian Open and French Open finals provide some pause – but these are still your consensus favorites heading into this year’s US Open. And with good reason.

Prior to the Querrey loss, Djokovic was on an all-time roll, winning four consecutive Grand Slam titles – making him just the third man in history to hold all four majors simultaneously (Don Budge, 1938; Rod Laver, 1962, 1969) – and claiming six tour titles this year against just three match losses. He has also reached the US Open semifinals nine years in a row and enters New York as the defending champion.

Meantime, Serena remains the preeminent player in women’s tennis – and perhaps women’s tennis history. While Angelique Kerber followed her Australian Open win with an early loss at the French, and Garbiñe Muguruza followed her Roland Garros title with an early setback at Wimbledon, Serena motors on. She avenged her Australian Open final loss to Kerber in the Wimbledon final to claim her 22nd career Grand Slam singles title, matching Steffi Graf for the most in the Open era, and as of Monday will increase her run at No. 1 in the world to 179 weeks and counting.

Oh, and she is tied with Chris Evert for the Open era record with six US Open singles titles – a seventh would make her the winningest player in the Open era both in terms of US Open and Grand Slam titles.

Look out for No. 2 (both of them): The 2016 hype has been deservedly centered on Serena and Djokovic, but the No. 2 players in the world have clearly established themselves as their primary challengers at this year’s US Open. Andy Murray was the runner-up to Djokovic in Melbourne and Paris before emerging at Wimbledon to win his third Grand Slam singles title in his 10th major final. And while she fell early at Roland Garros, rising world No. 2 Kerber is enjoying a career season at age 28, backing up her Australian Open title with an impressive run to the Wimbledon final; she did not drop a set in reaching the final and played gamely in her 7-5, 6-3 loss to a red-hot Serena.

Murray in particular should garner a lot of attention in Flushing Meadows, home to his maiden Slam title in 2012, as he has put a fair share of daylight between himself and world No. 3 Roger Federer in the world rankings. But don’t sleep on Kerber. The German rarely gets the big-time press, but she made her international breakthrough with a run to the semifinals at the 2011 US Open and is at her best on concrete.

Women’s tennis has a new star: Muguruza changed the narrative in women’s tennis with her victory at the French Open. The 22-year-old Venezuela-born Spaniard has been heralded for a number of years as a potential star, and she made good on that promise by rolling through the Roland Garros draw and defeating Serena in a taught two-set final.

Muguruza stumbled at Wimbledon, falling in the second round, but that is more likely a hiccup than any sign of real trouble. And while she has not yet performed well in Flushing Meadows – posting a career record of 1-3 – her powerful game, and new-found poise and confidence, certainly make her a threat, if not a potential title favorite.

Men’s tennis has some up-and-comers of its own: The Big Four no longer exists in the same form, and with every tournament it’s becoming more apparent that the next generation of challengers is edging closer to the top. This much was evident in Paris and London.

At 25, Wimbledon runner-up Milos Raonic is perhaps a little old to be considered a rising star, but he is the second-youngest player in the Top 16. More importantly, the Canadian has clearly upped his level this year – he also reached the semifinals in Melbourne – and armed with noticeably improved ground strokes and arguably the best serve in the game, he has to be considered a legitimate contender in Flushing Meadows.

As is the Top 16’s youngest player, 22-year-old Dominic Thiem, who took another step in his breakout season with a run to the semifinals at Roland Garros – his best Slam result to date – and figures to be a Top 8 seed at the US Open.

Other names to keep an eye on are 22-year-old Frenchman Lucas Pouille, a Wimbledon quarterfinalist, and fast-rising German teenager Alex Zverev, who advanced to the third round at both the French Open and Wimbledon. Throw in Croatian teen Borna Coric and 18-year-old American Taylor Fritz, and the ATP has plenty of young talent to crow about – and a number of potential challengers to Djokovic’s throne.

Venus Williams is a legitimate US Open contender (and so is Federer): At 36, Venus Williams is playing her finest tennis in years. Her run to the fourth round at the French Open was her best showing in Paris since 2010, and her semifinal showing at Wimbledon was her best performance in London since 2009 and her first trip to a Grand Slam final four anywhere since 2010.

Keep in mind, Venus played some good ball at last year’s US Open as well, pushing Serena to three sets in a high-quality quarterfinal. A potential Top 4 seed come this summer, the 2000-01 US Open champion has entered into the short list of contenders to win the 2016 event.

Speaking of graybeard challengers, Federer continues to play high-level tennis into his mid-30s. He may not have won a Grand Slam title since 2012, but his run to the semifinals at Wimbledon – where he lost a thrilling five-setter to Raonic – reaffirms the soon-to-be 35-year-old’s place on the short list of those who could hoist the trophy in New York.

For the record, with victories in 2016, Venus would become the oldest women’s singles champion since Molla Bjurstedt Mallory in 1926, and Federer would be the most senior men’s singles winner since Ken Rosewall in 1970.

Injuries have taken a toll on the bold-faced names: No woman was playing better tennis than Victoria Azarenka coming out of the fall hard-court swing through Indian Wells and Miami, kindling hopes of a third Serena-Vika US Open final. But she has played in only three events since, retiring in her first-round match in Roland Garros and pulling out of Wimbledon with a knee injury.

Azarenka is not alone. Federer pulled out of the French Open with a bad back, snapping a Grand Slam main draw streak that dated back to 1999; Rafael Nadal pulled out of the French prior to his third-round match and skipped Wimbledon as well; Caroline Wozniacki missed the French Open with an ankle injury; and Djokovic alluded to an injury after his loss to Querrey.

All could return in form for the US Open, but the injuries bear watching – as does the toll taken by a long season – and they could potentially open the door for a number of the aforementioned up-and-comers during this year’s Flushing fortnight.

The Americans should be a force at the Open: The U.S. had more players in the singles main draws of both the French Open and Wimbledon than any other country, and that is without the benefit of the multiple wild cards the Americans will receive in Flushing Meadows. Better yet, the U.S. players are making the most of the opportunities.

At Wimbledon, Querrey became the first U.S. man to reach a Grand Slam quarterfinal since the 2011 US Open (John Isner, Andy Roddick), and he was joined in the fourth round by Steve Johnson. Isner and Jack Sock, meantime, reached the third round both in Paris and at Wimbledon. Throw in rising stars like Fritz – who put a scare into No. 4 seed Stan Wawrinka at the All England Club – and encouraging showings from players like Donald Young, and an American man playing deep into the US Open draw seems as probable as it has in many years.

The American women, meantime, remain world class. An astounding 14 U.S. women are ranked in the Top 100 – easily the most of any country – and they’re performing well at the Slams. Four of the round-of-16 entrants at Wimbledon were American (Madison Keys, CoCo Vandeweghe and the Williams sisters) and six reached the round of 32 (also Sloane Stephens and Julia Boserup). Shelby Rogers was the breakout star of the French Open, where she advanced to the quarterfinals, and she, Serena, Keys and Venus all reached the fourth round at Roland Garros.

Friendly crowds and a familiar court surface should only help the American cause at the US Open – so don’t be surprised to see a lot of U.S. players suiting up on Labor Day and beyond.