Five-time major winner and defending British Open champion Phil Mickelson signs autograph’s during a practice round Thursday at Royal Liverpool. (Stuart Franklin/Getty Images)

Say a baseball season was conducted on a standard diamond — bases 90 feet apart, pitcher’s mound 60 feet 6 inches from home plate — for only 152 of 162 games. For the remaining 10, push the mound back 10 feet, bring the left field wall in behind the shortstop and let the grass grow over ankle tops.

Or raise the basketball rim to 11 feet. Or give football teams an extra down. But only for a couple of games per season.

This is what is presented to the world’s best golfers at the British Open. Hyperbole? Maybe. But for one week every year, in a tournament with the most tradition and (some would say) prestige, golfers are expected to play a game that only slightly resembles the one they play the other 51 weeks.

“There’s never really a standard golf shot,” U.S. Open champion Martin Kaymer said, and that addresses the heart of links golf, the sort of golf played where the sport was born, on turf that links the inland to the sea. Here, Royal Liverpool Golf Club lies along the River Dee, on the cusp of the Irish Sea.

What the British Open requires, then, is proper preparation, a re-familiarization with links golf in order to be ready for the test over the next four days. The problem: No one seems to agree on what that proper preparation might entail.

“I think it’s an advantage to play the Scottish Open on links golf,” said Phil Mickelson, who won the Scottish Open last year, then took the British Open at Muirfield the following week.

“I find it valuable coming up the week before,” said Adam Scott, the world’s No. 1 player, who arrived at Royal Liverpool last Thursday and played every day through Tuesday — including one 30-hole day — while the Scottish Open was contested up north.

Who’s right? “I’m still learning,” Matt Kuchar said. Join the club.

Take the two options presented by Mickelson and Scott. Mickelson took the better part of two decades to get comfortable with links golf, in which players typically have to flight the ball lower — under the sea breezes that can turn into downright gales — and use the ground as a friend, learning to bounce shots close to pins rather than attacking the green through the air, as if it’s a dartboard.

What better way, he figured, than playing in tournament conditions on a similar-style course such as Royal Aberdeen, site of the Scottish?

“Get acclimated to the time over here,” Mickelson said, ticking off his reasoning. “Get acclimated to seeing the ball bounce and the fescue and the thicker grasses on the greens and the long lag putts that we are going to have. And putting in crosswinds. Putting in crosswinds is brutally tough.

“All those things happened last week [in the Scottish Open]. And all those things, I believe, give the players that played a distinct advantage.”

Your turn, Mr. Scott.

“I feel I need to give myself a good week of really understanding [that] a 2-iron might run out 330 yards off a tee and that I need to hit a 4-iron from 156 yards into a green and actually hit it firm and not baby it up there,” Scott said.

“To get your head around that is really tough, and a lot of it is feel, and you need a bit of time, and you need to play, I think, to do that.”

Yet while Scott was here, working almost obsessively around Royal Liverpool, England’s Justin Rose was playing with Mickelson and the rest at Royal Aberdeen. Rose has tried it both ways, and he did stop for a practice round here on the Sunday before the Scottish Open. But he’s come to believe that truly understanding how the British Open will play involves feeling the competitive juices on links as well.

“You need to understand what your miss is or what the tendency is for it if it doesn’t go to plan,” Rose said. “I don’t think you really know that until you get a scorecard in your hand.”

Scott, who has played Royal Aberdeen and thinks it’s a “great track,” has a counterpoint nonetheless.

“The way I see it, and it might be wrong,” he said, “but why play that links when you can play this one?”

Rose, by chance, won the Scottish Open, so the answer might be that he out-earned Scott by $1,074,681 for the week’s work. Plus, he grew up playing links golf in England, and so it would seem to be a natural fit even after he has been away — playing, for instance, at lush Congressional Country Club, where he won the Quicken Loans National late last month.

But even a childhood on links courses might not help given the rest of the schedule on the PGA and European Tours. Two-time major winner Rory McIlroy grew up playing links all over Northern Ireland and professes a love for it. But he lives in Florida now, and his skills for this game have eroded.

“Especially if you play the majority of your golf in the U.S., you start to neglect some of the shots that you might need in conditions like this,” McIlroy said. “So if anything, I don’t think I’ve evolved that much as a links player. But I’ve been trying, especially the last few weeks, to play some shots, really practice hard on some of the shots that I might need this week.”

There is, too, a group of players (mostly American) who played in the John Deere Classic in Silvis, Ill., and took a red-eye flight overnight, arriving Monday morning. How prepared could they be after savaging TPC Deere Run, where winner Brian Harman was 22 under par? The strategy, the feel — the entire game, really — is different there.

“You need to really play a game,” Kaymer said. “It’s not about 155 [yards], 8-iron. . . . It’s never like this. You have to think so much. You have to be creative. You have to play with the slopes, with the weather, with the wind, everything.”

You have to, to an extent, forget what you know and start over again.