Imran Khan

Context: Khan made a lackluster first-class cricket debut at the age of sixteen in Lahore. By the start of the 1970s, he was playing for his home teams of Lahore A (1969-70), Lahore B (1969-70), Lahore Greens (1970-71) and, eventually, Lahore (1970-71). Khan was part of University of Oxford's Blues Cricket team during the 1973-1975 seasons. At Worcestershire, where he played county cricket from 1971 to 1976, he was regarded as only an average medium-pace bowler. During this decade, other teams represented by Khan included Dawood Industries (1975-1976) and Pakistan International Airlines (1975-1976 to 1980-1981). From 1983 to 1988, he played for Sussex. Khan made his Test cricket debut against England in 1971 Edgbaston. Three years later, he debuted in the One Day International (ODI) match, once again playing against England at Trent Bridge for the Prudential Trophy. After graduating from Oxford and finishing his tenure at Worcestershire, he returned to Pakistan in 1976 and secured a permanent place on his native national team starting from the 1976-1977 season, during which they faced New Zealand and Australia. Following the Australian series, he toured the West Indies, where he met Tony Greig, who signed him up for Kerry Packer's World Series Cricket. His credentials as one of the fastest bowlers of the world started to become established when he finished third at 139.7 km/h in a fast bowling contest at Perth in 1978, behind Jeff Thomson and Michael Holding, but ahead of Dennis Lillee, Garth Le Roux and Andy Roberts. As a fast bowler, Khan reached the peak of his powers in 1982. In 9 Tests, he got 62 wickets at 13.29 each, the lowest average of any bowler in Test history with at least 50 wickets in a calendar year. In January 1983, playing against India, he attained a Test bowling rating of 922 points. Although calculated retrospectively (ICC player ratings did not exist at the time), Khan's form and performance during this period ranks third in the ICC's All-Time Test Bowling Rankings. Khan achieved the all-rounder's triple (securing 3000 runs and 300 wickets) in 75 Tests, the second fastest record behind Ian Botham's 72. He is also established as having the second highest all-time batting average of 61.86 for a Test batsman playing at position 6 of the batting order. He played his last Test match for Pakistan in January 1992, against Sri Lanka at Faisalabad. Khan retired permanently from cricket six months after his last ODI, the historic 1992 World Cup final against England in Melbourne, Australia. He ended his career with 88 Test matches, 126 innings and scored 3807 runs at an average of 37.69, including six centuries and 18 fifties. His highest score was 136 runs. As a bowler, he took 362 wickets in Test cricket, which made him the first Pakistani and world's fourth bowler to do so. In ODIs, he played 175 matches and scored 3709 runs at an average of 33.41. His highest score remains 102 not out. His best ODI bowling is documented at 6 wickets for 14 runs.He holds the record for the best bowling figures by any bowler in an ODI innings in a losing cause(6-14). At the height of his career, in 1982, the thirty-year-old Khan took over the captaincy of the Pakistan cricket team from Javed Miandad. As a captain, Khan played 48 Test matches, out of which 14 were won by Pakistan, 8 lost and the rest of 26 were drawn. He also played 139 ODIs, winning 77, losing 57 and ending one in a tie. In the team's second match, Khan led them to their first Test win on English soil for 28 years at Lord's. Khan's first year as captain was the peak of his legacy as a fast bowler as well as an all-rounder. He recorded the best Test bowling of his career while taking 8 wickets for 58 runs against Sri Lanka at Lahore in 1981-1982. He also topped both the bowling and batting averages against England in three Test series in 1982, taking 21 wickets and averaging 56 with the bat. Later the same year, he put up a highly acknowledged performance in a home series against the formidable Indian team by taking 40 wickets in six Tests at an average of 13.95. By the end of this series in 1982-1983, Khan had taken 88 wickets in 13 Test matches over a period of one year as captain. This same Test series against India, however, also resulted in a stress fracture in his shin that kept him out of cricket for more than two years. An experimental treatment funded by the Pakistani government helped him recover by the end of 1984 and he made a successful comeback to international cricket in the latter part of the 1984-1985 season. In India in 1987, Khan led Pakistan in its first-ever Test series win and this was followed by Pakistan's first series victory in England during the same year. During the 1980s, his team also recorded three creditable draws against the West Indies. India and Pakistan co-hosted the 1987 World Cup, but neither ventured beyond the semi-finals. Khan retired from international cricket at the end of the World Cup. In 1988, he was asked to return to the captaincy by the president of Pakistan, General Zia-Ul-Haq, and on 18 January, he announced his decision to rejoin the team. Soon after returning to the captaincy, Khan led Pakistan to another winning tour in the West Indies, which he has recounted as "the last time I really bowled well". He was declared Man of the Series against West Indies in 1988 when he took 23 wickets in 3 Tests. Khan's career-high as a captain and cricketer came when he led Pakistan to victory in the 1992 Cricket World Cup. Playing with a brittle batting line-up, Khan promoted himself as a batsman to play in the top order along with Javed Miandad, but his contribution as a bowler was minimal. At the age of 39, Khan took the winning last wicket himself. In 1994, Khan had admitted that, during Test matches, he "occasionally scratched the side of the ball and lifted the seam." He had also added, "Only once did I use an object. When Sussex were playing Hampshire in 1981 the ball was not deviating at all. I got the 12th man to bring out a bottle top and it started to move around a lot." In 1996, Khan successfully defended himself in a libel action brought forth by former English captain and all-rounder Ian Botham and batsman Allan Lamb over comments they alleged were made by Khan in two articles about the above-mentioned ball-tampering and another article published in an Indian magazine, India Today. They claimed that, in the latter publication, Khan had called the two cricketers "racist, ill-educated and lacking in class." Khan protested that he had been misquoted, saying that he was defending himself after having admitted that he tampered with a ball in a county match 18 years ago. Khan won the libel case, which the judge labelled a "complete exercise in futility", with a 10-2 majority decision by the jury. Since retiring, Khan has written opinion pieces on cricket for various British and Asian newspapers, especially regarding the Pakistani national team. His contributions have been published in India's Outlook magazine, the Guardian, the Independent, and the Telegraph. Khan also sometimes appears as a cricket commentator on Asian and British sports networks, including BBC Urdu and the Star TV network. In 2004, when the Indian cricket team toured Pakistan after 14 years, he was a commentator on TEN Sports' special live show, Straight Drive, while he was also a columnist for sify.com for the 2005 India-Pakistan Test series. He has provided analysis for every cricket World Cup since 1992, which includes providing match summaries for the BBC during the 1999 World Cup. He holds as a captain the world record for taking most wickets, best bowling strike rate and best bowling average in Test, and best bowling figures (8 wickets for 60 runs) in a Test innings, and also most five-wicket hauls (6) in a Test innings in wins. On 23 November 2005, Imran Khan was appointed as the chancellor of University of Bradford, succeeding Baroness Lockwood. On February 26, 2014, University of Bradford Union floated a motion to remove Khan from the post over Khan's absence from every graduation ceremony since 2010. Khan, however, announced that he will step down on November 30, 2014 citing his "increasing political commitments". The university vice-chancellor Brian Cantor said Khan had been "a wonderful role model for our students". CANNOTANSWER

Question: Why did Imran Khan admit to occasionally scratching the side of the ball and lifting the seam?
Answer: CANNOTANSWER