Nick Kyrgios, No. 30 (20 years, 7 months)
The Aussie young gun revolution continued in 2015, with Kyrgios joining Bernard Tomic in the year-end Top 30 of the Emirates ATP Rankings. The Aussie turned in another strong campaign, highlighted by his first ATP World Tour final on the clay of Estoril in late April and a quarter-final run on home soil at the Australian Open. Kyrgios became the first player from his country to reach the quarters in Melbourne Park since Lleyton Hewitt in 2005, and the first teen to advance to the last eight at multiple majors since Roger Federer in 2001. He posted a 24-19 win-loss record overall, with a thrilling 6-7(2), 7-6(5), 7-6(12) upset of Federer at the ATP World Tour Masters 1000 event in Madrid also on his résumé.

Borna Coric, No. 44 (19 years, 1 month)
The highest-ranked teen in the Emirates ATP Rankings, Coric soared to a career-high World No. 33 in late July. Currently at No. 44, the sky’s the limit for the 19 year old from Croatia after reaching two ATP World Tour semi-finals, in Dubai and Nice, and notching his first Top 5 victory – a 6-1, 6-3 rout of Andy Murray. He achieved his best Grand Slam result in advancing to the third round at Roland Garros and got off to a winning start in his Masters 1000 debut at Indian Wells, reaching the second round as a qualifier. The Zagreb native also clinched his second ATP Challenger Tour title, triumphing on the clay of Barranquilla without dropping a set.

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Hyeon Chung, No. 51 (19 years, 6 months)
Chung has become Asia’s newest tennis sensation after crashing onto the scene in 2015. Just the second Korean to crack the Top 100 of the Emirates ATP Rankings, joining Hyung-Taik Lee, he vaulted 122 spots this year to a career-high World No. 51. The 19 year old won his first ATP World Tour match at the Masters 1000 event in Miami and later claimed his first on the Grand Slam stage at the US Open. One of nine different teens to lift ATP Challenger Tour trophies in 2015, Chung was victorious on four occasions – in Burnie, Savannah, Busan and Kaohsiung. He capped his season with a first ATP World Tour quarter-final in Shenzhen.

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Lucas Pouille, No. 78 (21 years, 9 months)
France’s rising star Pouille has enjoyed a steady ascent up the Emirates ATP Rankings since reaching the Round of 16 at the BNP Paribas Masters in Paris last year. The World No. 78 attained a career-high No. 64 spot in early August, following a stunning run to the semi-finals at the ATP World Tour 500 event in Hamburg as a qualifier. Also a semi-finalist as a lucky loser in Auckland, Pouille was calm under pressure, posting a 9-2 record in tie-break sets. He would cap his campaign with a final run at the ATP Challenger Tour event in Mouilleron Le Captif (l. to Paire).

Thanasi Kokkinakis, No. 80 (19 years, 8 months)
Kokkinakis was a key contributor to a history-making season for the teenage contingent. For the first time since 2008, four teens cracked the Top 100 of the Emirates ATP Rankings and the Aussie from Adelaide was a dominant force. The World No. 80 broke into the Top 100 for the first time with a maiden Challenger title in Bordeaux and qualified at six ATP World Tour events. Kokkinakis was clutch in Grand Slams as well, winning a match at his home major for the second straight year after saving four match points against Ernests Gulbis. He would prevail 8-6 in the fifth set and proceeded to claim another 8-6 thriller on the terre battue of Roland Garros, rallying from two sets down to defeat countryman Bernard Tomic. In addition, in Indian Wells, he became the first teen to reach the Round of 16 of an ATP World Tour Masters 1000 event since Tomic in Cincinnati 2012.

Alexander Zverev, No. 83 (18 years, 7 months)
The youngest player in the Top 100, 18-year-old Zverev was recognised for his sterling 2015 campaign in being awarded the ATP Star of Tomorrow presented by Emirates. The German claimed his first ATP World Tour Masters 1000 match win after emerging from qualifying in Miami. Zverev won 14 tour-level matches in total in 2015, reaching his second ATP World Tour semi-final on the clay of Bastad and securing his second Top 20 win (d. Anderson) en route to the Washington quarters. Zverev also won his first Grand Slam match, a 9-7 fifth set thriller over Teymuraz Gabashvili at Wimbledon, and was a doubles finalist in Munich alongside brother Mischa. His shining moment came in cracking the Top 100 with a second ATP Challenger Tour title on home soil in Heilbronn.

Kyle Edmund, No. 102 (20 years, 11 months)
Davis Cup champions Great Britain have a bright future with Kyle Edmund continuing his assault on the Emirates ATP Rankings. Peaking at a career-high World No. 99, Edmund finished the year at No. 102. The Brit enjoyed a strong first half of the season, qualifying at a Grand Slam for the first time at both the Australian Open and Roland Garros. He would beat Stephane Robert in five sets on the clay for the second tour-level match win of his young career. A maiden Challenger title in Hong Kong in late January would be followed by more success on the circuit, hoisting the trophy on the hard courts of Binghamton and clay of Buenos Aires to cap his campaign. In total, Brits posted an 8-0 record in Challenger finals in 2015.

Yoshihito Nishioka, No. 117 (20 years, 2 months)
Nishioka’s 2015 season will be remembered for his audacious behind-the-back hot shot at the Aptos Challenger, but there was much more to the Japanese’s campaign to be impressed with. Closing in on the Top 100 of the Emirates ATP Rankings, the 20 year old concluded the year at World No. 117 after successful qualifying campaigns in Delray Beach, Roland Garros, Washington and the US Open. He notched his first ATP World Tour main draw wins in Delray Beach, reaching the quarter-finals, and his first at the Grand Slam stage in beating Paul-Henri Mathieu in five sets in New York. Nishioka capped his campaign with a title run on home soil at the ATP Challenger Tour event in Toyota.

Jared Donaldson, No. 134 (19 years, 2 months)
The 19 year old from Providence, Rhode Island, quietly constructed an impressive 2015 season. Donaldson registered his first ATP World Tour match victory in Memphis and would follow that up with a second on the grass of Newport, a third on the hard courts of Atlanta and another at the Masters 1000 level in Cincinnati in August. On the ATP Challenger Tour, the American earned his maiden title in Maui to open the season and reached the final in Sacramento, falling to fellow young gun Taylor Fritz. It was the first Challenger final between two teens since 2007.

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Elias Ymer, No. 136 (19 years, 8 months)
In 2016, Sweden will host its first ATP Challenger Tour tournament in 20 years. The Ymer brothers – Elias and Mikael – are a big reason why, putting the Scandinavian nation back on the tennis map. Elias became just the second player (Dancevic, 2011) to emerge from qualifying at all four Grand Slams in one season, securing his spot as one of 10 teens in the US Open main draw. He also won two matches in reaching the Round of 16 at the ATP World Tour 500 event in Barcelona, stunning Nick Kyrgios 9-7 in a deciding tie-break en route. The Swede would get his hands on a trophy as well, claiming his maiden Challenger title in Caltanissetta, Italy.

Others Making Noise
There were four more teens in the year-end Top 200 of the Emirates ATP Rankings, with Russians Karen Khachanov and Andrey Rublev, and Americans Taylor Fritz and Frances Tiafoe making strides. Rublev made the most noise of the foursome, becoming the first teen to win matches at five different ATP World Tour events since Rafael Nadal in 2004. With Rublev, Coric, Chung and Zverev notching victories at the Masters 1000 event in Miami, it marked the first time in tournament history that four players aged 18 and younger advanced to the second round. Fritz and Tiafoe also won their first matches on the ATP World Tour, with the former advancing to the second round in Nottingham and the latter doing so in Winston-Salem. Also, Fritz became just the second player aged 17 and younger to win consecutive Challenger titles when he triumphed in Sacramento and Fairfield.

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The ability to quickly adjust to different surfaces and conditions is a neccessity on the 62-tournament circuit. Here’s a look at some of the best performers in 2015 by surface this year:

Clay Courts (minimum 10 tie-breaks)
With victory at Munich in May, Andy Murray became the first British player to capture a clay-court title since Buster Mottram at 1976 Palma. He went on to beat Rafael Nadal for the first time on red dirt to clinch his 10th ATP World Tour Masters 1000 crown at Madrid. Novak Djokovic’s only loss came to Stan Wawrinka in a four-set Roland Garros final.

Hard Courts (minimum 10 matches)
Djokovic put together 11 and 16-match winning streaks on hard courts in 2015, contesting 11 finals on the surface (8-3). He lost three times to Roger Federer at Dubai, ATP World Tour Masters 1000 Cincinnati and in the round robin stage at the Barclays ATP World Tour Finals. Federer went 4-3 in hard-court title matches.

Grass Courts (minimum 5 matches)
Djokovic dropped three sets – two to Kevin Anderson in the fourth round and one to Federer in the final – en route to his third Wimbledon title, which equalled the record of his coach, Boris Becker (1985-86, ’89). He is now 14 matches unbeaten on grass courts. Rajeev Ram was also unbeaten on lawns, picking up the Newport crown (d. Karlovic).

Outdoors (minimum 10 matches)
Nine of Djokovic’s 11 titles in 2015 came outdoors, with a 28-match winning streak from early March to his Roland Garros final loss to Stan Wawrinka. Murray improved on his 2014 hard-court tally (45-16, .738) to finish year-end No. 2 in the Emirates ATP Rankings for the first time.

Indoors (minimum 10 matches)
Djokovic captured his 26th ATP World Tour Masters 1000 trophy – one behind all-time leader Rafael Nadal – at Paris, before going on to lift his fifth title at the Barclays ATP World Tour Finals in London. Federer added a seventh Basel crown in his 12th hometown final.