Jordan Spieth has won the first two 2015 majors, the Masters and U.S. Open, to be the first player since Tiger Woods in 2002 to get halfway to the single-season Grand Slam.
Of course, Spieth's incredible season has spurred talk that he could win the Open Championship and PGA Championship to be the first player to complete the modern Slam in one year. So, what are the odds of Spieth pulling off something that's never been done?
According to ESPN's FiveThirtyEight, Spieth has a less than 1 percent chance of winning the Grand Slam. They took a look at all of the players since 1958, when the PGA went from match play to medal play, who have won consecutive majors and what they did next. Only Tiger Woods in 2000 managed to win either of the next two majors.
Going back further into the modern definition of the majors, only Ben Hogan in 1953 managed to win the next leg of the Grand Slam, taking the Open Championship at Carnoustie. He couldn't compete in the PGA Championship which overlapped with the Open.
FiveThirtyEight says betting houses like Bovada give Spieth about a 9 percent chance to win each of the next two majors. Multiple them together for the most basic of calculations and you realize the bookmakers believe Spieth has a mighty small chance to win all four majors in one year.