The Open can be unpredictable. The weather can change -- sunny one minute, sideways rain the next. Add in the unknown with this Open: The oldest major is at Royal Portrush for the first time in 68 years. So, aside from a few locals who grew up around these links -- Rory McIlroy, Graeme McDowell, Darren Clarke and Brooks Koepka's caddie, Ricky Elliott -- almost the entire field comes in with little knowledge of the venue.
So what will happen? Our experts take their swings.
Matt Barrie, ESPN
Open champion: Tommy Fleetwood
Why he'll win: I'm not getting suckered in to the "home course" narrative when it comes to Rory McIlroy. But I will fall into the European trap, and Tommy Fleetwood fits perfectly. Coming off a T-12 at Carnoustie last year and four top 10s this year, Fleetwood has the game to quietly stay in the hunt going into the weekend. His scoring average has been spotty this year, but he'll find his comfort at Royal Portrush and win his first major.
David Bearman, ESPN Chalk
Open champion: Xander Schauffele
Why he'll win: While others may go with favorites, like McIlroy or top-ranked players Brooks Koepka and Dustin Johnson, I'll go with the X-man. He's been in the top six in five of his 10 career majors, including a T-2 at Carnoustie last year. This year's major circuit has featured him finishing T-2 (Masters), T-16 (PGA) and T-3 (U.S. Open). Schauffele is 13th in shots gained off the tee, 14th tee-to-green, 28th putting and seventh in overall shots gained, a formula that should work this week for his breakthrough major win.
Michael Collins, ESPN.com
Open champion: Brooks Koepka
Why he'll win: While every player, caddie and analyst will tell you that Mother Nature is the biggest deciding factor when it comes to who is in position to win The Open, betting against Brooks Koepka right now is just not smart money. Looking at the field this week, there is not one golfer I see as a threat to Brooks. If his name hits the top of the leaderboard early in the week, everyone (including the other golfers) will already know it's over.
Michael Eaves, ESPN
Open champion: Tommy Fleetwood
Why he'll win: He can hammer the ball when he needs to, but is also really good at flighting the ball down when the conditions require it. Plus, he's got the grit in his game to deal with whatever Royal Portrush and/or Mother Nature throws his way.
Chris Fallica, ESPN
Open champion: Rory McIlroy
Why he'll win: It's not an original pick, but I'm fairly certain he will be in contention come Sunday given that his past four Opens have each produced top-5 finishes. The local knowledge will come in handy here, and I don't think the pressure or stage of trying to capture The Open in his home country will be too big for Rory, who leads the Tour in strokes gained: total and tee-to-green. As is always the case with McIlroy, if he makes putts, he wins.
Charlotte Gibson, ESPN The Magazine
Open champion: Tiger Woods
Why he'll win: While I'm mourning the fact that it's the last major of the season, I'm also feeling like it's my last chance to go big and choose someone whom I've been eager to pick all year but have hesitated for many reasons: Tiger Woods. Look, I know he's only had eight official stroke-play starts since last year's Tour Championship. And I know he missed the cut at the PGA Championship at Bethpage Black. But I'm convinced that Woods' strategy of playing less than once a month in stroke-play and waking up at 1 a.m. back home in preparation for The Open will pay off. To top it all off, a green jacket and Claret Jug in the same year will take us all back to the heydays of Woods for which we all still yearn (or maybe I just yearn for them).
Mike Golic, ESPN
Open champion: Dustin Johnson
Why he'll win: It's just a matter of time.
Mike Greenberg, ESPN
Open champion: Rory McIlroy
Why he'll win: He has home-course advantage, and it's been too long since he won a major.
Bob Harig, ESPN.com
Open champion: Rory McIlroy
Why he'll win: He's such an obvious pick, it makes me nervous to pick him. It certainly would be an incredible story if McIlroy could win a second Claret Jug, this one coming in his home country, where an Open seemed so unlikely to return just a few years ago. McIlroy is more familiar with Royal Portrush than any of the contenders, but he's also got a game that's been in top form all year, with two victories and a slew of high finishes. It almost seems too good to be true, but McIlroy is due to break what is now a five-year absence of major titles.
Andy North, ESPN
Open champion: Rory McIlroy
Why he'll win: He'll be great or not be in contention, depending on how he handles all the local noise. He has so much local knowledge on a course not many have played.
Ian O'Connor, ESPN.com
Open champion: Rory McIlroy
Why he'll win: This one's easy. He grew up on the course, shot 61 here at age 16, and is long overdue after going nearly five years without winning a major. It would be a great, great story for Rory to win in Northern Ireland after The Open returned to his country for the first time in 68 years. I think he'll deliver it. Rory resumes his quest to become the greatest European player ever with major title No. 5.
Nick Pietruszkiewicz, ESPN.com
Open champion: Rickie Fowler
Why he'll win: OK, I promised I'd stop this. I can't keep picking a guy who hasn't won a major because, well, every time I've picked him I've been wrong. But here we go again. He's only had one top-20 since early May, a T-14 at the Memorial a month ago. So, we're saying he's due, right? Yes, he has the ball-striking and creativity that The Open requires. He's always owned an aggressive putting streak, which is good for the typically slower greens that come with this part of the world. So, again, let's give it a go. This is the week Fowler finally gets his.
Peter Lawrence-Riddell, ESPN.com
Open champion: Brooks Koepka
Why he'll win: At this point it seems almost foolish to pick anyone else. He won the PGA and finished second at the U.S. Open and T-2 at the Masters. Maybe he doesn't win, but he's going to be in contention -- that seems like a given. Koepka has never played in Northern Ireland, but his caddie (Ricky Elliott) is from Portrush and grew up playing on the course. But honestly, his caddie could be from another planet and Koepka would still be the pick this week.
Mark Schlabach, ESPN.com
Open champion: Rory McIlroy
Why he'll win: It seems too easy to pick the guy who grew up playing Royal Portrush and owns the course record. But all of Northern Ireland is going to be cheering for McIlroy, and he has a great track record in The Open with four consecutive top 5s. McIlroy hasn't played great in the major championships this year, but I think his talent and local knowledge are going to be difficult to beat. Plus, he'll be better than most when the wind starts howling and the rain falls later in the week.
Scott Van Pelt, ESPN
Open champion: Tommy Fleetwood
Why he'll win: Feels like time for both him and a European Tour player to be in the winner's circle. I'm flying blind on Portrush. Golf Jesus is my co-pilot.
Kevin Van Valkenburg, ESPN The Magazine
Open champion: Tiger Woods
Why he'll win: I'm a little less confident in this pick than I was two months ago, but I'm sticking with my gut. No one is better at thinking his way around a links course, at handling the elements and the quirky bounces, than Tiger. Even when his game wasn't all the way back, he was still in the mix at Carnoustie. This Open reminds me a bit of Royal Liverpool in 2006, when it was played at a course that hadn't hosted the championship for 39 years. Much like Portrush, Tiger hadn't previously played there, but he still dominated by relying on strategy, not power. If the wind blows and the greens are firm, he'll be in contention.