There are plenty of reasons the 2019 Red Sox have represented not just a disappointment but a mystery. Yet perhaps the most vexing aspect of a team that on paper bears very close resemblance to its championship predecessor is a brutally bad performance in the venue that should be most conducive to success: Home.

Rick Porcello chews on a towel in the dugout after he was removed in the top of the fifth inning.

With a 6-5 loss to the Twins on Tuesday, they are 34-35 at home, and 34-33 at Fenway Park.

(Those two losses to the Yankees in London were technically home affairs, and while on one hand that characterization seems absurd, the contests sort of looked like games at Fenway given the obscene number of runs permitted to the Red Sox’ opponent.)


The reason for the team’s home woes is fairly straightforward: As a group, the starters have been abysmal in Fenway this year. With the six-run, four-plus-inning yield by Rick Porcello to Minnesota on Tuesday, the team’s starters now have a 5.16 ERA in home contests – including a 5.04 mark at Fenway. By comparison, the Dodgers entered Tuesday with a home ERA that was exactly half of that (2.52) posted by the Red Sox in Boston.

“I ran into a number the other day, I think runners in scoring position, the OPS is if not the worst, it’s one of the worst in the big leagues against our starters,” noted Red Sox manager Alex Cora. “Keeping the ball in the ballpark, limiting traffic, that’s the most important thing to avoiding the big inning that’s been going on from the get-go.”

More specifically: It has been going on from the get-go at home. Sox starters have been bad, though just short of awful on the road with runners in scoring position (.292/.358/.523). As ugly as those numbers look, the team would be in a very different position if it hadn’t been far worse in such circumstances at Fenway.


With runners in scoring position at home, the Red Sox rotation has produced jarringly awful numbers: A .311 average (second-worst in MLB), .407 OBP (easily the worst in MLB), and .543 slugging percentage (tied for second worst).

Put another way: Imagine a lineup filled with nothing but Xander Bogaerts and J.D. Martinez, and you’d have a decent approximation of the average production against Red Sox starters with runners in scoring position at home this year.

Under those circumstances, it should come as little surprise that rallies have gone from a slow drip (runners on base) to a steady flow (more and more runners on base) before finally becoming a flood (hits that score multiple runs). It’s the wash, rinse, repeat of crooked-numbered rallies on the visitor’s line on the scoreboard.

At the heart of that struggle, the team has misfired far too many pitches with runners on base. Aside from flashes from Chris Sale, the Red Sox rotation lacks the stuff to be able to mislocate pitches over the heart of the plate and emerge unscathed — particularly this year, when every ball hit in the air threatens to clang off or clear a fence. Yet that’s precisely what’s happened on numerous occasions for the Sox at Fenway this year.

“It’s pretty obvious that those balls that are getting [hit] are in the middle of the plate or don’t have any action on them,” rued Porcello.


But it’s not just him. In fact, Porcello’s 4.92 ERA at Fenway this year is both superior to his 7.01 mark outside of Boston – including London – and better than the performance of his other rotation mates.

The pattern of poorly located pitches at the costliest moments is one that keeps happening for the Red Sox at Fenway this year, particularly against elite competition.

The Red Sox are 10-20 in home games (10-18 at Fenway) against teams with records of .500 or better. Their rotation has a 5.88 ERA (5.62 ERA at Fenway) in those contests.

That is no way to forge a path to a playoff berth, let alone a championship. Yet as much as the Red Sox recognize that they need something better, they have little choice but to hope that their current starters suddenly find something in the remaining 24 games of 2019 (and 12 at Fenway) that they’ve been missing for almost the entire season.

Tuesday marked the start of a pivotal week for the Red Sox, the onset of seven home games in as many days against the Twins and Yankees. After a survival series against the Angels in Anaheim – one in which the team had gotten just seven of its 32 innings from starting pitchers — the club hoped that Porcello might be able to conjure the same magic he produced earlier this season, when he carved the Twins over seven shutout innings June 17.


Of course, that outing was in Minnesota. On Tuesday at Fenway, it was – again – a different story.

“We trust these guys. These guys have [performed at Fenway] their whole careers. It just happens that this year they haven’t been able to be consistent at it. You see flashes, and then,” Cora said with sigh, “something like this happens.”

Over and over and over.

Alex Speier can be reached at alex.speier@globe.com. Follow him on twitter at @alexspeier.