Rory McIlroy Has Won Back-to-Back Masters — Now the Entire Betting World Is Watching the Calendar Grand Slam

Nobody has won the calendar Grand Slam in the modern era of professional golf. One man has ever done it at all — Bobby Jones in 1930, and the game looked nothing like what it is today. Rory McIlroy just won back-to-back Masters titles, completing a career Grand Slam at Augusta in 2025 after 17 attempts and then doubling down with a second green jacket in 2026. Three majors remain this calendar year. The betting world is paying close attention to whether McIlroy can do something that hasn’t been done in 95 years.

The Historical Weight of What Would Have to Happen

The calendar Grand Slam means winning the Masters, the PGA Championship, the US Open, and The Open Championship in the same calendar year. McIlroy has checked the first box. Now he needs three more. For context on how hard that is: the closest anyone in the modern era came was Tiger Woods, who held all four major trophies simultaneously across two calendar years from 2000 to 2001 — the so-called Tiger Slam. Woods never actually won all four in one calendar year. Ben Hogan is the last player to win three majors in a single year, and that was 1953. The calendar Grand Slam is not just difficult. It is historically unprecedented in the professional era.

McIlroy’s major résumé now includes the US Open (2011), the PGA Championship (2012 and 2014), The Open Championship (2014), and the Masters (2025 and 2026). Six majors total. He is in rarefied company, and with three legitimate chances remaining this year, the conversation is no longer theoretical.

The Remaining 2026 Majors and McIlroy’s Odds

The three remaining majors this calendar year are all on the schedule within the next three months. The PGA Championship runs May 14-17 at Aronimink Golf Club in Pennsylvania, where McIlroy is currently listed at +650 at DraftKings. The US Open follows June 18-21 at Shinnecock Hills in New York — McIlroy sits at +700, trimmed down from +800 in the wake of his Masters victory. The Open Championship is July 12-19 at Royal Birkdale in England, where he is priced at +750.

Scottie Scheffler looms over all three. He is the defending champion at both the PGA Championship and The Open, and he is favored at +400 or shorter at each. Scheffler played a bogey-free final two rounds at Augusta this year and still finished second — a reminder that McIlroy’s path runs through one of the best players in the world at full health across all three remaining events.

Cameron Young is another name worth tracking after his T3 finish at Augusta. He is now priced at 22-1 for both the PGA Championship and the US Open, and 25-1 for The Open. Young at those numbers has value if you believe Augusta was a confidence-builder for a player with the ball-striking ability to contend at all three venues.

The Math on a Calendar Grand Slam

If you work through the implied probabilities on McIlroy’s current odds — +650 at the PGA, +700 at the US Open, +750 at The Open — his combined probability of winning all three remaining majors comes out to roughly 2 percent. That translates to approximately 50-1 if you could bet the calendar Grand Slam as a single outright wager. Nobody is offering that contract yet, but the implied price exists in the market whether or not you can bet it that way.

The venue alignment does favor McIlroy in ways that matter. Shinnecock Hills, where he won the 2011 US Open, is a familiar track with positive history attached to it. Royal Birkdale, a links course on the Lancashire coast close to his Northern Ireland roots, fits his natural ball flight. He knows how to win at both places. The PGA at Aronimink is newer territory, but McIlroy has won two PGA Championships already and understands how to peak for that event.

Why This Conversation Is Different Now

A year ago, the calendar Grand Slam was a fun hypothetical. Today, McIlroy has won two Masters in a row, completed the career Slam, and is entering the prime of a run that looks as dominant as anything in men’s golf since Woods. At 2 percent probability, the math says it probably doesn’t happen. But the same math said a lot of things about McIlroy at Augusta over the years that turned out to be wrong. Watch the odds move on him heading into Aronimink. If he’s inside +400 by the week of the PGA, the market will be telling you the conversation is getting very real very fast.