Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray were the great rulers of the modern era. Despite having won far fewer Grand Slam titles than the other three, the Scotsman managed to become World number 1, to win three Grand Slam titles and also to win two Olympic gold medals.
As of 2020, the trio of Federer, Nadal, and Djokovic has instead been referred to as the Big Three due to Murray's repeated struggles with injuries, relative absence from the ATP Tour, and vastly smaller achievements.
There has been some discussion since 2015 whether Murray should be included as part of this elite group, initially because he has won far fewer Grand Slam titles when compared to the other three. Some have objected to including Murray in the Big Four while excluding Stan Wawrinka, who has also won three majors in the same period.
Wawrinka himself has countered this objection, citing his lack of consistency compared to the Big Four. A comparison between the career performances of the two shows Murray clearly ahead in all other parameters. Murray's statistics are often in the top ten in the Open Era, which highlights his consistency in comparison to Wawrinka.
In a recent interview, famous golfer Jon Rahm mentioned the dominance of the Big Four.
Rahm on the Big Four
I think we are in an era right now where it's going to be hard to have somebody distance themselves," Rahm said on Tuesday during practice for this week's PGA Championship at the TPC Harding Park in San Francisco.
"We have so many great players. At any given point for two or three months, one of us can get h*t and take the No. 1 spot." Rahm envisions a scenario where the top ranking could be shared among four or five premier players much like tennis' big four of Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray.
"I think we might be entering an era where we bounce back and forth," he said. "It's an exciting time in golf. It's similar to tennis. You have Rafa, Djokovic and Federer who are competing at the same time.
Who is No. 1, you don't know, it depends on who plays better that year." Three-time champion Novak Djokovic will lead this year’s US Open playing field, featuring younger ATP Tour stars Dominic Thiem, Daniil Medvedev, Stefanos Tsitsipas and Alexander Zverev, who will be eying an opportunity to make their Grand Slam breakthroughs.