This week marks the 40th anniversary of the Emirates ATP Doubles Rankings.

During the first decade of Open tennis, the sport experienced phenomenal growth with prize money increasing each year at a rate of between 20 and 50 per cent. But only those players who had competed in tournaments over the preceding 12 months, with prize money of $25,000 or more, were listed in the Emirates ATP Rankings, established on 23 August 1973.

“Prize money was weighted 80/20 in the favour of singles players,” former player Mike Estep, later an ATP Board member, told ATPWorldTour.com. “You’d go to play singles, then, once you lost, you’d focus on doubles. You simply couldn’t make a living as a doubles specialist.”

In March 1976 a little more than 300 players were world-ranked, with one ATP point or more. Each player competed in both singles and doubles competitions on a 95-tournament circuit.

Jimmy Connors ruled world tennis. But who was the best doubles player? It was a difficult question to answer.

With just four full-time staff, who had recently relocated from a corner of Jack Kramer‘s business office in Los Angeles to Dallas, the ATP, already one of the major forces behind the phenomenal growth of professional tennis, unveiled its latest innovation: the Emirates ATP Doubles Rankings in early March 1976. The system gained immediate credibility and legitimacy.

Raymond Moore, the first Chairman of the ATP Computer Rankings Committee, successfully lobbied the Men’s International Professional Tennis Council, which oversaw the sport until 1989, with the help of three ATP representatives, to officially select the Emirates ATP Doubles Rankings to determine entries and seeding in Grand Prix events. “It got through by a vote of 5-4,” Marshall Happer III, the future Commissioner of the MIPTC, told ATPWorldTour.com.

“The Emirates ATP Doubles Rankings recognised those players who performed better in the team format, rather than on the singles court and became the arbiter of a player’s ability to compete on the circuit,” Charlie Pasarell told ATPWorldTour.com.

Using the ATP’s existing sliding point scale, based on the Emirates ATP Rankings, total points were divided by tournaments played to determine a player’s average. If a player had played in less than 12 tournaments, his total points were still divided by 12.

“Dot Matrix prints outs would hang around locker rooms,” recalls Estep. “Players would often look for their ranking, but also their closest rivals. They’d also look to ensure the points were accurate. At the time, no one realised the importance of doing the rankings each week, only the year-end rankings mattered. Doubles points were initially based on the points awarded in singles competition, minus the second round because of the differences in the size of the draw.

“But as the 1970s drew to a close, $25,000 tournaments were now considered small events. The criteria needed to change as both sets of rankings were based on prize money. It was a challenge, particularly in doubles, to keep the rankings system accurate.”

In 1979, when the United States Tennis Association (USTA) had a competing computer ranking system, the ATP’s secretary Jim McManus and Happer III, the then organiser of the USTA’s Satellite and Challenger Series Tournaments, joined forces to grow the number of players listed in the Emirates ATP Rankings and Emirates ATP Doubles Rankings.

It proved to be a masterstroke. ATP points began to awarded to tournaments divided into three classes: star, qualifying (assigned or called by the MIPTC) and satellites. Star tournaments were classified according to its prize fund and the number of participants.

“The MIPTC worked with the ATP to give points to third and fourth tier satellite tournaments, under $25,000,” said Happer. “It ensured new sponsors were attracted to the sport and the change subsequently developed ATP Challenger Tour events.”

By the mid 1990s, players realised that it was possible to make a living by playing just doubles. “With better treatment and changes in racquet technology, players in their early 30s were able to switch from the singles court to doubles and prolong their careers,” said Pasarell.

Jim Pugh, a doubles No. 1 for 12 weeks in 1989, told ATPWorldTour.com, “When the tournaments started being required to pay for every main draw players’ hotel room as long as they were still in the tournament, there were many more ‘doubles specialists’ than before. And a new trend started: a few of the doubles teams started having a doubles coach, where I had only known the singles players to have coaches before.”

“Doubles changed dramatically when they increased the prize money and coaches started traveling more with the teams,” David Pate, who spent 25 weeks at No. 1 in the Emirates ATP Doubles Rankings, told ATPWorldTour.com. “The Jensen brothers [Luke and Murphy] promoted themselves and the sport tremendously, and I believe that the Bryan brothers [Bob and Mike] have carried the torch from then on.”

Since March 1976, the Emirates ATP Doubles Rankings have provided a fair analysis of a player’s performance as well as an objective means to determine entries into tournaments.

Forty seven players from 17 different countries have reached the summit of the Emirates ATP Doubles Rankings, with 24 different players finishing year-end No. 1. Only six doubles players have spent more than 100 weeks at No. 1 including, Mike Bryan (454 weeks), Bob Bryan (439), John McEnroe (269), Todd Woodbridge (204), Daniel Nestor (108) and Anders Jarryd (107).

Marcelo Melo, the current incumbent since 2 November 2015, has spent 18 consecutive weeks at No. 1.

Today, the Emirates ATP Doubles Rankings still bears some of the hallmarks of the original sliding point scale. With more than 1,830 listed players, it is now based on calculating a player’s total points from his best 18 results from all eligible tournaments, including the elite season-ending Barclays ATP World Tour Finals played in a 52-week ranking period. For entry purposes there are no mandatory events, however, once a player is accepted into the main draw of one of these 12 tournaments, his result counts towards his ranking, whether or not he participates.

Like the Emirates ATP Rankings, it has become an indispensable part of tennis, accepted universally by players, tournaments and fans.

John Isner produced a fearsome serving display against Australian Bernard Tomic in Melbourne Sunday to lead the United States into the quarter-finals of the Davis Cup. Isner fired 49 aces in four sets to beat Tomic 6-4, 6-4, 5-7, 7-6(4).

The U.S. will next host either Belgium or Croatia on American soil.

Isner’s serve on Kooyong’s grass court was largely unreturnable for the last two sets, when he fired 33 aces and forced Tomic to frequently guess which side he would serve. Isner, who fired 20 aces and was not broken in his straight-sets win over Sam Groth on Day 1, gave up just one break to Tomic Sunday, dropping serve in the final game of the third set.

“I wasn’t event close on his serve in the third and fourth sets but fortunately for me I was serving pretty well myself . It was a big win for me but more importantly it was a big win for our country and our team,” Isner told Tennis Channel.

“We’ve lost in the round of 16 the last two years so it was a very tough pill for us to swallow. But we’re in the quarter-finals now and we’ll be looking forward to having a home tie coming up.”

GREAT BRITAIN 2, JAPAN 1
Venue: Barclaycard Arena, Birmingham, GBR (hard – indoor)

Andy Murray and Jamie Murray are quickly becoming a doubles powerhouse. The brothers gave Great Britain a 2-1 lead with a dominant 6-3, 6-2, 6-4 victory over Japan’s Yoshihito Nishioka and Yasutaka Uchiyama in Saturday’s doubles rubber.

The Murrays improved to 6-0 together in Davis Cup doubles play, firing 12 aces and not facing a break point throughout the one-hour and 53-minute affair. Defending champion Great Britain is bidding to record its 150th tie win this weekend. They turn to Murray to achieve the milestone on Sunday, as the World No. 2 clashes with fellow Top 10 star Kei Nishikori in a blockbuster fourth rubber.

Murray did not drop a set in two meetings with Nishikori last year, prevailing on the clay of the Mutua Madrid Open and on the hard courts of the Rogers Cup in Montreal.

ITALY 3, SWITZERLAND 0
Venue: Adriatic Arena, Pesaro, ITA (clay – indoor)

Italy is the first nation to punch its ticket to the quarter-finals, following a ruthless 6-3, 6-1, 6-3 doubles victory by Simone Bolelli and Andreas Seppi over Marco Chiudinelli and Henri Laaksonen.

The Italian duo eliminated the Swiss side, who were without the services of Top 5 stalwarts Roger Federer and Stan Wawrinka, in just one hour and 45 minutes. Switzerland has dropped consecutive World Group first round ties since lifting the trophy in 2014.

Italy extended its home winning streak to six straight ties, successfully advancing to the quarter-finals for the third time in four years. The nation will either host Argentina or travel to Poland in July. Argentina currently leads 2-1 on the road in Gdansk.

SERBIA 1, KAZAKHSTAN 2
Venue: Pionir Hall, Belgrade, SRB (hard – indoor)

Novak Djokovic and Serbia finds themselves in an unfamiliar position following a comprehensive 6-3, 7-6(3), 7-5 doubles defeat to Kazakhstan’s Andrey Golubev and Aleksandr Nedovyesov on Saturday. The singles World No. 1 and former doubles No. 1 Nenad Zimonjic fell in two hours and 29 minutes, committing an uncharacteristic 56 unforced errors.

Serbia will look to claw back from 2-1 down when Djokovic faces Mikhail Kukushkin in Sunday’s reverse singles. The 28 year old is riding a 22-match win streak in best-of-five set matches and carries a 28-7 record in Davis Cup singles rubbers.

Taylor Fritz took in a Los Angeles Lakers game on Friday night, ahead of his ATP World Tour Masters 1000 debut next week at the BNP Paribas Open in Indian Wells. It was an ATP invasion at the Staples Center, with fellow stars Roger Federer, Tommy Haas and Milos Raonic also in attendance for the Lakers’ 106-77 loss to the Atlanta Hawks.

The Southern California native, who trains in nearby Carson, was given an exclusive tour of the facilities, including the locker room.

“It was so nice to check out the locker room and meet the players. I enjoyed the experience,” Fritz told ATPWorldTour.com. “It was weird. All those guys were definitely bigger than me. Some of them towered over me. I felt so small.

“It’s great to see some of those athletes taking an interest in tennis and what I do. That’s amazing. I look up to those guys a lot.”

Stars of Tomorrow: Taylor Fritz

Fritz had the opportunity to meet Lakers stars Roy Hibbert and Metta World Peace, along with head coach Byron Scott and ESPN broadcaster Mike Tirico. The youngest player in the Top 100 of the Emirates ATP Rankings, the 18 year old also had an unexpected encounter with Federer and Haas on the court.

“We talked about tennis, scheduling and what we’re up to. I chatted a little about soccer with Federer. They’re both really good guys. I definitely wasn’t expecting to run into them.”

Fritz was awarded a wild card into the Indian Wells main draw, where he will make his first appearance at an ATP World Tour Masters 1000 event. Fellow American teen Frances Tiafoe was also given a wild card, along with Juan Martin del Potro, Rajeev Ram and Mackenzie McDonald.

Bob Bryan and Mike Bryan have given the United States a 2-1 edge over Australia in their first-round Davis Cup tie after a clutch five-set win over Lleyton Hewitt and John Peers in Melbourne.

Making his debut as Davis Cup captain, Hewitt temporarily ended his recent retirement to play the doubles rubber after replacing an injured Nick Kyrgios in the four-man Aussie squad. Hewitt didn’t disappoint home fans with a spirted returning display – particularly on the backhand wing – and combined with Peers to push the Bryans to the limit.

Coming into the tie without a title in 2016, the Bryans were lacking some of their normal confidence. But Bob produced one of his best returning displays and Mike was sharp at net in the 6-3, 6-3, 4-6, 4-6, 6-3 win on grass at the historic Kooyong venue in suburban Melbourne.