More famously, he is the only player in tennis history to have twice won all four of tennis' Grand Slam singles titles in the same year�first as an amateur in 1962, and then again as a professional in 1969. For this achievement, Laver is considered by many tennis fans to be the greatest player of all time.

Laver was a young boy when he left school to pursue a career in tennis that would end up lasting 23 years. He was US Junior Champion in 1956 and Australian Junior Champion 1957. His first major singles title was the Australian Championships in 1960, where he beat fellow Australian Neale Fraser in a titanic five-set final. He then captured his first Wimbledon singles crown in 1961.

In 1962, Laver became only the second male player after Don Budge in 1938 to win all four of the Grand Slam titles in the same year. That year, he set a record for the amateur era, winning 21 titles. In addition to the Grand Slam, he also won the Italian Championships and the German Championships � thus achieving a difficult clay court triple of Paris, Rome and Hamburg that has been achieved only one other time (by Lew Hoad in 1956). The biggest hurdle on his way to the Grand Slam was the French on slow clay, where Laver had to overcome three five-setters in a row from the quarterfinals onwards. In his quarterfinal with Martin Mulligan he had to save a matchpoint in the fourth set - with a backhand volley, coming in behind a second serve. In his Paris final, he came back from two sets down and 0-3 down in the fourth set, to defeat Roy Emerson. At Wimbledon his progress was much easier. Laver lost only one set in the whole tournament, to Manuel Santana in a turbulent quarterfinal, who held a setpoint for a two set lead, but was soundly beaten afterwards. At Forest Hills Laver rounded off his Grand Slam rather easily, losing only two sets on his way and beating Roy Emerson again in the final.

At the time, the Grand Slam events were only open to amateur players, who were given (under the table) little more than cost of living money for their appearances in tournaments.

Although of only medium build (1, 75 m), Laver developed a technically complete serve-and-volley game, with aggressive groundstrokes to back it up. As Dan Maskell put it, he was "technically faultless, from his richly varied serve to his feather-light touch on drop volleys plus a backhand drive carrying destructive topspin when needed or controlling slice when the situation demanded it". His lefthanded serve was well disguised and wide swinging. His wristy groundstrokes on both flanks were hit with topspin, an innovation in the 60s, as was the attacking topspin lob, which Laver developed into a weapon. His stroke-technique based on quick shoulder turns, true swings and exquisite timing. Especially his backhand, often hit on the run, was a point-ender. Laver was very quick and mobile, and had a gigantic left forearm. Rex Bellamy writes: "The strength of that wrist and forearm gave him blazing power without loss of control, even when he was on the run and at full stretch. The combination of speed and strength, especially wrist strength, enabled him to his ferocious winners when way out of court". At the net he had forcing volleys, often hit as stroke volleys. Especially on the backhand he could hit sharp underspin angles as well. Julius Heldman points out: "He is competent on low balls, handling them with underspin for control, but he will cream any ball at waist level or higher". He was difficult to lob, because of his springing agility, and when forced to retreat he could come up with a vicious counterpunch.

As an amateur, Laver was a somewhat flashy player, often a late starter. He had to learn to control his adventurous shotmaking, and to integrate the percentage tennis into his game, when he turned professional. In his prime, he could adapt his style to all surfaces and to all conditions demanded. Laver had a great record in five-set-matches, often turning things around with subtle changes of tactics or by simply hitting his way out of danger. When he got into the 'zone', he went for broke. Then he would, as Heldman explains, "literally jump and throw his racket at the ball with all the force he could muster, wrist and arm snapping over at the hit."