BOSTON – After a five-hour, 14-minute, back-and-forth battle between the American League’s top-seeded Tampa Bay Rays and the Boston Red Sox, who secured a wild-card berth on the final day of the regular season, crew chief Sam Holbrook sat in the interview room at Fenway Park on Sunday and read from the umpire’s manual. Which was maybe the last in a long list of indicators that Boston’s 6-4 walk-off win in ALDS Game 3 would be talked about for years to come.

“It's item 20 in the manual, which is, balls deflected out of play, which is in reference to official baseball Rule 5.06(b)(4)(H),” Holbrook began.

“It says, if a fair ball, not in flight, is deflected by a fielder and goes out of play, the award is two bases from the time of the pitch.”

He went on to explain that the wall functions as an extension of the ground — you can’t catch a ball that bounces off the ground because it’s no longer in flight, for instance, and a ball that bounces off the ground and goes over the fence is a ground-rule double. But if a fielder intentionally sends a ball out of play after he’s obtained possession of it, then it’s two bases from wherever the baserunners are at the time of deflection.

“Very simple,” Holbrook said. “From an umpire's standpoint.”

To his credit, as confusion descended over Fenway Park and the baseball-viewing world, Rays manager Kevin Cash seemingly understood that the pivotal moment — the opportunity to plate a go-ahead run in the 13th inning — was not going to go his team’s way.

“By rule, it's just a ground-rule double,” he said later of Hunter’s Golden Hip Check, or Renfroe’s Ricochet, or whatever they’ll come to call the play that preceded and perhaps even made possible the Red Sox victory to take a commanding 2-1 series lead.

But still — stakes being what they were, and the flow of the game turned off such that suddenly there were just a bunch of men in matching outfits standing around on a patch of well-lit grass in the middle of Boston with the afternoon long since having given way to late night — he had to try something to stop it.

“Is there anything that I can do?” Cash asked Holbrook after coming out of the dugout amid the chaos.

He had managed his Rays to their first 100-win season in a stacked division historically dominated by teams with longer pedigrees and bigger payrolls. He had watched his team take an early lead, watched the Red Sox take it back, and then craftily deployed nine pitchers to keep his club close while a couple of young already or on-the-verge October legends conspired to tie it up.

It had seemed that there wasn’t much left to do but wait to see how it all played out and try to worry about who would start Game 4 later.

And then, on a 3-2 count with two outs in the top of 13th inning and Yandy Diaz at first, Kevin Kiermaier had launched a ball all the way to the right field wall. In a sequence of utmost import, it went: Off the wall, off the ground, off Hunter Renfroe’s hip, and over the short porch. All told, a double by rule. Diaz, who had been running on contact, would have to stop at third despite an almost indisputable alternate timeline where he scores easily if the ball remains in play, if Renfroe had been in position to field it cleanly instead of running up to the wall in a miscue that might have changed the course of the series in the Red Sox's favor.

“Everything he does is just turned into gold out there,” Kiermaier said in shell-shocked amazement later.

Holbrook told Cash they could review the play. But all they could really check was whether Renfroe had volleyed the ball over the wall on purpose — triggering the “two bases from the position of the runners at the time when the ball was kicked or deflected.”

Fortunately for the Red Sox, it was clearly a mistake.

The Rays didn’t protest, didn’t say it was unfair, and after the game they seemed more resigned than resentful. It wasn’t even the only quirky call worth rehashing. Cash agreed with the decision to award Randy Arozarena second but not third on Kyle Schwarber’s accidental obstruction. And disagreed with the replay review that upheld the out call on Manuel Margot’s attempted steal of second.

It all feels a little arbitrary, but then again so are three strikes.

Asked if he thought the Red Sox were “lucky” to end the night in a jubilant throng around home plate instead of staring dejectedly into the middle distance just beyond the dugout railing, Kiké Hernández — who set an MLB postseason record with his eight hits over the past two games, which not so promptly went on to be completely overshadowed — said no.

“Because we played a good game — played a good game and played the elements, we took care of home-field advantage. We did what we had to do to win the game. Got big hits, got big homers.”

The biggest homer was a two-run blast that landed in the seats atop the Green Monster by Christian Vázquez in the bottom of the 13th. It snapped a four-inning scoreless stretch in which both teams would deplete their bullpens and tap into their intended Game 4 starters. It sent the Red Sox into Monday with a chance to advance to the ALCS with one more win at home.

That part wasn’t luck. And neither was so much else in the hard fought, well matched baseball marathon on the eve of the Boston Marathon. Like a gutsy, emotional performance from Nick Pivetta to keep the score knotted after the Sox squandered a lead. Or the eighth-inning home run from the Rays’ 20-year-old prodigy Wander Franco. Or the many missed opportunities as each team left 10 men on base who could have been the go-ahead runs earlier in the night.

But, anyway, here’s Hernández describing the Kiermaier-Renfroe-Diaz play that everyone will remember most:

“I was speechless because I don't know if you guys have seen that before. I've never seen that before in my life. I wasn't sure what was going to get called. I wasn't sure if the runners had to return. I wasn't sure if it was going to be like an errant throw where the runner would get two bags. Like I had no idea.

“Luckily, it went our way.”

The point is not that Hernández is a hypocrite. Rather that the physical, visceral drama of a baseball game is always being shaped by weird hops and the little-known provisions in a decades-old rulebook. You can’t think they detract from the magic because the sport doesn’t exist without them. Holbrook called it “cut and dried” and just as it’s always been “ever since I came in the game” — he’s right, and so was the application of the rule, which is just as arbitrary as any other.

But rules can be changed.

It doesn’t make the Red Sox's win any less real to say that the top of the 13th inning — which was not so much controversial as it was illuminating — exposes the fallacy of distinguishing between intentional and unintentional regarding balls knocked out of play. A ball that touches a fielder should be considered their purview regardless of possession. The runners should always get two bases from the point of deflection. Umpires are reluctant to make discretionary calls, like where to place the runner, but if anything, removing that provision would eliminate the need to determine fielder intent.

Maybe the rule will be changed in response and the next Yandy Diaz will advance and the next Rays will take a 5-4 lead. And maybe the next Red Sox will still walk it off anyway. Or maybe not, but it’s something to talk about.

“Games like tonight, we'll remember it forever,” Kiermaier said, despite acknowledging the heartbreak of the 13th-inning call.

In a sea of conflicting emotions and outsized arcane pedantry, that’s a sentiment everyone can agree on.