Tiger Woods came closest to meeting the modern definition of golf's Grand Slam by holding all four modern major championships simultaneously — the U.S. Open, Open Championship, and PGA Championship in 2000 and the 2001 Masters — although not in the same calendar year. This has been referred to as a "Consecutive Grand Slam," "Non-calendar year Grand Slam" (derived from other sports with a four-major format), or, after the only player to achieve it in golf, a "Tiger Slam". In fact, even before Woods accomplished this, there was much debate over the definition of "Grand Slam." Fred Couples said, "I don't know how I can put it more simply . . . if he wins all four, it's a Slam." As noted above, however, because there is no official definition, there is no definitive answer.