Around 130 years after the first "modern" tennis tournaments, the ATP had tried to implement fundamental changes to what has been a simple elimination system. Namely, instead of a knock-out system that sends you out as soon as you suffer a defeat (outside the ATP Finals, of course), the ATP officials wanted to impose the round-robin system to some 13 lower-ranked ATP tournaments in 2007, with Adelaide serving as the testing ground.
It was anything but simple, though, with 16 players competing in the first round (four qualifiers, three players with the wild card and nine based on the ATP ranking) to reach the round-robin system and join 16 other players who were waiting for them.
Once this process ended, we had eight groups with three players competing to determine the group winners and the quarter-final field. The top seed Novak Djokovic wrote history as the first player who won the ATP title in this new format, beating Jan Hajek and Alun Jones in Group 1 before ousting Paul Goldstein and Joachim Johansson in the quarters and semis to reach the final against the wild card Chris Guccione.
The Serb claimed the challenging final 6-3, 6-7, 6-4 to lift the title, with the players having another chance to compete in the round-robin system in Delray Beach in February. The winner was Xavier Malisse despite the fact he lost in the group phase to Rainer Schuettler (he had to win only one set to advance into the quarters in that one), producing the unseen precedent in the men's tennis history outside the already mentioned ATP Finals!
Vina del Mar and Buenos Aires followed the same pattern before the fifth event - the Tennis Channel Open in Las Vegas in March - exposed all the system's flaws compared to a suitable old elimination method!
The round-robin system stayed for only five tournaments in early stages of 2007.
Group 1 gathered the defending champion James Blake, Juan Martin del Potro and Evgeny Korolev, and they all finished with one victory and two sets won and lost.
The main problem occurred when Juan Martin del Potro retired against James Blake due to respiratory issues while trailing 1-6, 1-3. The Argentine was eliminated since this match went into his losing record but not those he completed, with the organizers deciding the quarter-finalist between Korolev or Blake.
Instead of searching for the number of games won (James was on 15-14 and Evgeny on 17-18), they reached for a head-to-head card and announced that the Russian is through to the last eight. In another twist in the tale, the ATP Chairman and President Etienne de Villiers had to be involved, making the following statement: "James Blake was awarded the group on the basis that the rules were not sufficiently explained.
James was within just a few games of winning this match comfortably to advance. Juan Martin has stated that he would have completed the match had he been fully aware of the implications of his retirement." Korolev was sent home with an $11,000-plus consolation prize, and this all happened just three hours before the quarter-final matches were about to start, creating a chaotic and unpleasant situation for both the organizers and the players themselves.
The round-robin system was on thin ice, and the organizers of the famous grass events at Queen's and Newport said they would think twice before actually using it. However, they didn't have to consider that since the ATP abandoned it on March 21!
As most of the players were hoping for, Las Vegas served as the last ATP tournament that implemented the round-robin format, with the ATP heading back to a standard elimination system that keeps things plain and simple.