The debate is as old as the hills: What sort of course should host a U.S. Open? Opinions vary, considering how much a person values tradition, reputation, geography and innovation. It depends on your taste in hills, too.

Erin Hills, a practically brand new layout carved from farmland 50 minutes northwest of Milwaukee, is the site for the championship that begins Thursday. And it could not be more distinct from Shinnecock Hills in Southampton, which will be the venue next year, celebrating its status as the only course to hold U.S. Opens in three centuries.

So this week represents quite a juxtaposition. As golfers arrive at the sprawling grounds in Wisconsin (Erin Hills’ footprint is more than twice that of Shinnecock Hills), the official countdown begins (ticket sales start tomorrow) for the 2018 Open at one of the U.S. Golf Association’s founding-member clubs.

Think of it this way: The last time Shinnecock followed a first-time Open venue was 1896, when there had been only one U.S. Open ever. The exclusive club that sits on a main road to one of the world’s great resort areas was added to the National Register of Historic Places in 2000. That same year, entrepreneur Bob Lang began accepting bids to build Erin Hills. The latter is a privately owned public course that never has witnessed a sizable professional tournament.

The USGA nonetheless fell in love with the landscape, awarding the 2008 U.S. Women’s Amateur Public Links to Erin Links before the construction was completed. The association, wanting to mix forward-thinking with its respect for history, agreed in 2010 to bring the Open there.

As a golf entity, it remains a vast question mark, which possibly a way appropriate for a pro golf season that has no overriding theme. Defending U.S. Open champion Dustin Johnson entered 2017 as the favorite any time he showed up, but he never even teed it up in the Masters because he was injured in a fall at his Augusta rental home. He has not regained his form.

Rory McIlroy has been injured. Jordan Spieth and Jason Day have not achieved the dominance for which they seemed destined two years ago. Masters champion Sergio Garcia has been essentially on a victory lap since his heartwarming triumph in April. Phil Mickelson declared himself doubtful at best to play this week because the Open conflicts with his daughter’s high school graduation. Mickelson is hoping for a postponement Thursday — along the lines of Bethpage in 2009 — so he can make it, but the forecast is for sun.

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No one can say what type of player is favored at Erin Hills, with its 7,693 yards of tumbling fairways and deep bunkers, because hardly any of them have played it in competition. Early speculation has tied it to Chambers Bay, the new course that hosted the 2015 U.S. Open to generally poor reviews. It appeared shockingly brown on the Fox telecasts.

But Jordan Spieth, the winner at Chambers Bay and a quarterfinalist in the 2011 U.S. Amateur at Erin Hills, said of the latter venue, “ It’s not as tricky. I think it’s a little bit more in front of you. It’s a very different style golf course even though it’s kind of coming off ahead of time as being similar.

“Chambers Bay, you had big mounds to play off of onto the greens. This is kind of rolling hills. Although neither one has a tree that I remember on the golf course, it was kind of a new style American links type, they both are, I think they’ll play tremendously different,” he said.

It certainly has a different pedigree than Shinnecock Hills. Charlie Howe, championship director for the 2018 Open, has been in Wisconsin all week, helping his USGA colleagues. “It’s all hands on deck,” he said on his cell phone the other day as he strung gallery ropes. “From a golf course standpoint, outside the ropes, there is a little more space here for hospitality facilities and the Fox TV compound.”

On the other hand, Shinnecock has the benefit of familiarity — with Southampton Town and Suffolk County officials, with traffic flow, with logistics in general. Also, there is a built-in base for volunteers. Still, he and his staff are recruiting more (2018volunteers.usga.org). There are openings for people to be marshals, help at the practice tee, operate scoreboards, use lasers to measure the length of shots.

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Howe moved to Westhampton last October to begin preparations. It did not take him long to learn there is no place quite like Shinnecock, particularly after he played the course recently.

“Members have told me that this is the best they have ever seen the course come out of a winter,” he said. “It was such a mild winter. We’re hoping to have one more of those.”

Winter seems a long way away now. It figures to be a wide-open Open week in Wisconsin, with the clock having started ticking down toward Southampton.