At age 21, Jordan Spieth has won his second Major and become the most celebrated player in golf. He is also halfway to one of the most difficult feats in sport, the Grand Slam.

Indeed, “difficult” may be selling the challenge short. In its modern incarnation, no one has ever completed a Grand Slam in golf, and no one has come especially close.

The term comes from bridge, where the taking of all 13 tricks has been called a Grand Slam since at least the early 1800s. The first golfer said to have completed a Grand Slam was Bobby Jones in 1930, but the four tournaments he won were different from the modern set and included two amateur events.

The Masters, and thus the possibility of a modern Grand Slam, began in 1934. But winning the Masters, the United States Open, the British Open and the PGA Championship in the same year has proved to be too much of a challenge for even the world's most dominant golfers.

The Masters and the US Open double has only been secured in the same year seven times. The first player to do it was Craig Wood in 1941. A Grand Slam was not possible that year, as no British Open was played because of the second World War. In any case, Wood was eliminated from the PGA, which was then played as a match play tournament, in the round of 32.

In 1951, Ben Hogan took the first two Majors. But he would have faced a significant hurdle for a Grand Slam bid: the British Open started a day after the PGA ended.

After suffering terrible injuries in a car crash in 1949, Hogan played a light schedule, and in the end he elected not to compete in either of the last two Majors in 1951.

Events overlapped

In 1953, after once again winning the Masters and the United States Open, he did travel to Scotland to play in the only British Open of his career. He won, but once again could not play in the PGA because the events overlapped. That was the only time a Masters and United States Open winner also won the British Open. It was Hogan’s ninth, and final, Major.

Though the victory was front-page news, there was not much hand-wringing over his missing the PGA; the modern concept of the Grand Slam would not solidify in the public’s mind until the early 1960s.

Arnold Palmer, who often spoke about his desire to win the Grand Slam, won the first two legs, the Masters and the US Open, in 1960. He came close in the British Open that year, losing to Ken Nagle by just a stroke.

Jack Nicklaus's turn came in 1972. Like Palmer, he missed a British Open win by a stroke, losing out to Lee Trevino.

After Palmer and Nicklaus, it took 30 years and the emergence of another of the game’s greatest golfers to get another Masters-United States Open winner.

In 2002, Tiger Woods won his seventh and eight Majors and went into the British Open with realistic hopes very much alive for the elusive Slam. But he shot an 81 at Muirfield on Saturday in terrible conditions, and wound up tied for 28th. It was the first time he recorded a score in the 80s in his professional career.

Woods had amazingly won all four Majors consecutively, from 2000 to 2001; though he was highly lauded for that feat, it was not considered by most to be a true Grand Slam because it did not take place in a single calendar year.

A Grand Slam is so difficult that winning all four Majors at any time in one's career is a much-heralded accomplishment itself. Only five players have done it: Woods, Nicklaus, Hogan, Gary Player and Gene Sarazen.

Best performance

The women’s Grand Slam has proved just as difficult. The best performance was by Babe

Didrikson Zaharias

, who won all three Majors contested in 1950, five years before the start of the LPGA Championship.

Fifth major

In 2013, women’s golf added a fifth major. That year Inbee Park won the first three; it is not clear if it would have been generally recognized as a Grand Slam if she had won one of the last two.

Tennis's Grand Slam is the most comparable to golf's but is somewhat easier, having been accomplished twice by Rod Laver and once by Don Budge on the men's side, and three times by women, Maureen Connolly, Margaret Court and Steffi Graf.

There are a host of other “Grand Slams,” including the four-run home run in baseball, and the Grand Slams of rugby (going 5-0 in the Six Nations competition), exploring (reaching the North and South Pole and all of the Seven Summits), and fly-fishing (catching a bonefish, a tarpon and a permit in a single day). But most of them have proven attainable.

That brings us back to Spieth, who now looks forward to the British Open at the Old Course at St Andrews starting July 16 and the PGA Championship at Whistling Straits in Wisconsin beginning Aug. 13.

Can he buck history and actually win the Grand Slam?

He is significantly less experienced than the others who won the first two legs. Woods was the youngest, at 26; the others were all over 30. Hogan, Palmer, Nicklaus and Woods had all won Majors before.

To win the Masters and the United States Open at 21 is an eye-opening accomplishment, sure to be celebrated for years on its own. To ask Spieth to now go further than previous golfing greats could ever manage and and win the next two Majors is a tall, tall order.

But that does not mean that everyone will not be watching to see if he can do it. New York Times