A number of dominant players of their eras have failed to achieve the Career Grand Slam because of their inability to win a particular major. Sam Snead and Phil Mickelson (through 2020) failed to win a U.S. Open; Arnold Palmer, Tom Watson, and Jordan Spieth (through 2020) failed to win a PGA Championship; Lee Trevino and Rory McIlroy (through 2020) failed to win The Masters; Byron Nelson and Raymond Floyd failed to win the Open Championship, at which the former competed only once. These shortcomings have been attributed to various factors: a particular major is ill-suited to a player's game (this was cited especially with regard to Trevino and The Masters); the player lacked the ability to fully adapt to that major; the player simply experienced bad luck (Mickelson finished second a record six times at the U.S. Open); or war had led to the cancellation of a major during the player's prime.