Question: What is the occupation of the man who has won the most green jackets in golf?

full_context: Document 1: Jack Nicklaus: Jack William Nicklaus (born January 21, 1940), nicknamed The Golden Bear, is an American retired professional golfer. In the opinion of many observers, he is the greatest golfer of all time. During a span of more than 25 years, he won a record 18 major championships, three ahead of Tiger Woods (15). Nicklaus focused on the major championships—Masters Tournament, U.S. Open, Open Championship and PGA Championship—and played a selective schedule of regular PGA Tour events. He has competed in more major championships (164) than any other player. He finished with 73 PGA Tour victories, third on the all-time list behind Sam Snead (82) and Tiger Woods (81).
Document 2: List of men's major championships winning golfers: Jack Nicklaus has won the most majors; he won 18 during his career. Second on the list is Tiger Woods, who has won 14 majors to date; his most recent major victory was at the 2008 U.S. Open. Walter Hagen is third with 11 majors; he and Nicklaus have both won the most PGA Championships with five. Nicklaus also holds the record for the most victories in the Masters, winning the competition six times. Nicklaus also shares the record for the most U.S. Open victories with Willie Anderson, Bobby Jones and Ben Hogan, each winning this competition four times. Harry Vardon holds the record for the most Open Championship victories, winning six times during his career. Nicklaus, Woods, Hogan, Gary Player and Gene Sarazen are the only golfers to have won all four of the majors during their career, thus achieving the so - called career slam.
Document 3: Masters Tournament: The Masters was started by noted amateur champion Bobby Jones and investment banker Clifford Roberts. After his grand slam in 1930, Jones acquired the former plant nursery and co-designed Augusta National with course architect Alister MacKenzie. First played 84 years ago in 1934, the tournament is an official money event on the PGA Tour, the European Tour, and the Japan Golf Tour. The field of players is smaller than those of the other major championships because it is an invitational event, held by the Augusta National Golf Club.
Document 4: Masters Tournament: By tradition, the winner of the previous year's Masters Tournament puts the jacket on the current winner at the end of the tournament. In 1966, Jack Nicklaus became the first player to win in consecutive years and he donned the jacket himself. When Nick Faldo (in 1990) and Tiger Woods (in 2002) repeated as champions, the chairman of Augusta National put the jacket on them.
Document 5: 1965 Masters Tournament: Jack Nicklaus, age 25, won the second of his six Masters titles with a score of 271 (−17), at the time a tournament record, three strokes better than Ben Hogan's 274 in 1953. It was equaled in 1976 by Raymond Floyd and surpassed in 1997 by Tiger Woods' 270 (−18). Nicklaus' winning margin of nine strokes also stood until 1997, when Woods was victorious by twelve strokes to win his first green jacket. It was the fourth of a record 18 major titles won by Nicklaus in his career.
Document 6: The Honda Classic: Some celebrated players have won this tournament, including Nicklaus in 1977 and 1978, the only consecutive winner in its history. However, the tournament had acquired a reputation for struggling to attract the top players as it moved from course to course in South Florida. Since 2007, The Honda Classic has seen a vastly improved player field, largely due to the decision to make PGA National the tournament's permanent home.
Document 7: List of men's major championships winning golfers: Jack Nicklaus has won the most majors, achieving 18 victories during his career. Second on the list is Tiger Woods, who has won 14 majors to date; his most recent major victory was at the 2008 U.S. Open. Walter Hagen is third with 11 majors; he and Nicklaus have both won the most PGA Championships with five. Nicklaus also holds the record for the most victories in the Masters, winning the tournament six times. Additionally, Nicklaus shares the record for the most U.S. Open victories with Willie Anderson, Bobby Jones and Ben Hogan, each winning four times. Harry Vardon holds the record for the most Open Championship victories, winning six times during his career. Nicklaus, Woods, Hogan, Gary Player and Gene Sarazen are the only golfers to have won all four of the majors during their career, thus achieving the so - called career slam.
Document 8: List of Masters Tournament champions: Jack Nicklaus holds the record for the most Masters victories, winning the tournament six times during his career. Nicklaus is also the oldest winner of the Masters: he was 46 years 82 days old when he won in 1986. Nicklaus, Nick Faldo, and Tiger Woods co-hold the record for most consecutive victories with two. Woods was the youngest winner of the Masters, 21 years 104 days old when he won in 1997. Woods also set the record for the widest winning margin (12 strokes), and the lowest winning score, with 270, 18 below par (- 18) in 1997. The latter was equaled by Jordan Spieth in 2015.
Document 9: 1997 Masters Tournament: Tiger Woods won his first major championship, twelve strokes ahead of runner-up Tom Kite. Through 2019, the margin of victory and four-day score of 270 (−18) are tournament records. Woods also became both the youngest (21) and the first non-white player to win at
Document 10: Masters Tournament: The first winner of the Masters Tournament was Horton Smith in 1934, and he repeated in 1936. The player with the most Masters victories is Jack Nicklaus, who won six times between 1963 and 1986. Arnold Palmer and Tiger Woods have each won four, and Jimmy Demaret, Gary Player, Sam Snead, Nick Faldo, and Phil Mickelson have three titles to their name. Player was the tournament's first overseas winner with his first victory in 1961. Two - time champions include Byron Nelson, Ben Hogan, Tom Watson, Seve Ballesteros, Bernhard Langer, Ben Crenshaw, José María Olazábal, and Bubba Watson.
Document 11: List of golfers with most PGA Tour wins: The column for Major refers to so - called ``Professional Majors ''. The U.S. Amateur and the British Amateur were also considered to be majors for much of their history, but these championships are not considered here. Players under 50 years of age are shown in bold. During the last 30 years, only three players have won PGA Tour events after their 50th birthday. A golfer becomes eligible to compete on PGA Tour Champions, against other older players, at that age. Craig Stadler won in 2003 at age 50, Fred Funk won in 2007 at age 50, and Davis Love III won in 2015 at age 51. Sam Snead is the oldest to win a PGA event, at age 52, in 1965. Others who have won PGA Tour events past age 50 include Jim Barnes, John Barnum, and Art Wall, Jr. The rarity of golfers winning a non-senior event at that age is not restricted to the PGA Tour; Miguel Ángel Jiménez is the only golfer to win a European Tour event after turning 50, doing so in 2014.
Document 12: Masters Tournament: The tournament has a number of traditions. Since 1949, a green jacket has been awarded to the champion, who must return it to the clubhouse one year after his victory, although it remains his personal property and is stored with other champions' jackets in a specially designated cloakroom. In most instances, only a first - time and currently reigning champion may remove his jacket from the club grounds. A golfer who wins the event multiple times uses the same green jacket awarded upon his initial win (unless he needs to be re-fitted with a new jacket). The Champions Dinner, inaugurated by Ben Hogan in 1952, is held on the Tuesday before each tournament, and is open only to past champions and certain board members of the Augusta National Golf Club. Beginning in 1963, legendary golfers, usually past champions, have hit an honorary tee shot on the morning of the first round to commence play. These have included Fred McLeod, Jock Hutchinson, Gene Sarazen, Sam Snead, Byron Nelson, Arnold Palmer, Jack Nicklaus, and Gary Player. Since 1960, a semi-social contest at the par - 3 course has been played on Wednesday, the day before the first round.
Document 13: Men's major golf championships: Along with his record 18 major victories, Jack Nicklaus also holds the record for most runner - up finishes in major championships, with 19, including a record 7 at the Open Championship. Phil Mickelson has the second most with 11 runner - up finishes after the 2016 Open Championship, which includes a record 6 runner - up finishes at the U.S. Open, the one major he has never won. Arnold Palmer had 10 second places, including three in the major he never won, the PGA Championship. There have been three golfers with 8 runner - up finishes -- Sam Snead, Greg Norman and Tom Watson. Norman shares the distinction of having lost playoffs in each of the four majors with Craig Wood (who lost the 1934 PGA final -- at match play -- on the second extra hole).
Document 14: List of golfers with most PGA Tour wins: This is a list of golfers who have won five or more official (or later deemed as historically significant) money events on the PGA Tour. It is led by Sam Snead with 82 wins, Tiger Woods with 80, and Jack Nicklaus with 73.
Document 15: 1954 Masters Tournament: The 1954 Masters Tournament was the 18th Masters Tournament, held April 8–12 at Augusta National Golf Club in Augusta, Georgia. Sam Snead defeated defending champion Ben Hogan by one stroke in an 18-hole Monday playoff to win his third Masters tournament. It was Snead's seventh and final major victory.
ground_truth: an American retired professional golfer
sub_queries: who has won the most green jackets in golf Answer: Jack Nicklaus
Who is Jack Nicklaus ? Answer: an American retired professional golfer