The NLU guys asked this question in their post-round, and I thought it was fun, so I'll ask it here: who of Morikawa, Rory, Spieth, or Brooks (or Phil, if we are to be truly fair) is the most likely to complete the career grand slam?
Keeping in mind that only 5 guys have ever done it with the modern definition of majors, my instinct is to say that none of them do, and I think that's probably going to be the case. That being said, if I had to pick one, it's actually more tough than I expected. My first thought was that it's obviously Spieth or Rory simply because they need 1 instead of 2. But Rory is just not doing it for me anymore, and I seriously wonder if he's ever going to win one again. Like it's one thing to play well in majors, which he certainly has, but it's another thing to put yourself in position to win them on Sunday, which he hasn't. Then, with Spieth, there's always the problem of his style of play. He's not dominating with the driver like most top guys do, and that's the direction the game is headed and has been heading for the past decade. We've already seen the downside of that with how he's slumped way harder than any of Collin, Rory, or Brooks the past three years, although with Collin and to a lesser extent Brooks they haven't been around the top level as long which means they've had less opportunity to enter into a slump. You only get one chance every year to complete the career grand slam, so it's not at all unreasonable to think that with a game that may not be geared towards consistency, that the stars might just not ever align for him there.
Then there's the other two. Morikawa is the flavour of the month and it's easy to say that he's just gonna win in bunches, but he also has the most glaring weakness to his game of any of them with his putting. We just saw this week what happens when his balky putter suddenly turns into Tiger's Scotty Cameron from 2000, but the vast majority of the time that's not going to happen for him. Plus, there's the obvious fact that he's the freshest on the scene and thus the least proven. Lastly, Brooks checks a lot of boxes for me but that health scares me a lot. He's by far the most frequently injured golfer of any of the top guys - unless you're still counting Tiger, or maybe Jason Day if you really want to stretch it - and that's the top way to lose elite form. I think you also have to wonder if he's really interested in investing himself to playing into his 40s. I think he cares more about golf than he wants everyone to think, but I do wonder if there's a hypothetical scenario where a decade or so from now, Brooks has suffered some injuries, lost a bit of form, and he just says he's had enough.
If I had to rank them by likelihood of winning the career grand slam, I'd probably go Brooks > Spieth > Rory > Morikawa. I think Morikawa wins a couple more majors but not the grand slam, I think Rory comes close but doesn't win any more majors, Spieth comes close as well but wins multiple majors aside from the PGA, and Brooks just keeps putting himself in position to win enough that he has the best chance to get it done. With all that in mind, I might as well start preparing myself for Phil to go ahead and win the US Open before any of these guys do it.