BOSTON -- In the wee hours of Monday morning — moments after the team had lost three of four to the Yankees, and minutes before embarking on a four-day All-Star break — Ryan Sweeney was asked to give his Red Sox a mid-term grade.

“I'd say,” offered the outfielder, “maybe a C-plus.”

Whether Professor Sweeney is a tender grader, or a tough one, is debatable. Some see the Sox at 43-43 and take that mark as evidence of the resilience they've exhibited in the face of unrelenting injuries.

Others recognize it as the club's worst first-half record in 15 years, and expected more despite an overcrowded disabled list considering the Yankees have, like the Sox, been down three key starting pitchers, their closer, plus their everyday left-fielder — yet hold a 9½-game advantage over Boston in the division.

What's subject to much less debate, however, is that the Sox have been the definition of mediocre over their first 86 games, the evenness of their record a perfect reflection of a club that hasn't played well enough to leave itself any slack, but hasn't played poorly enough to compromise its playoff contention.

With Jacoby Ellsbury and Clay Buchholz nearly ready to return, presumably followed by Carl Crawford and Andrew Bailey, things might get better. But even when those reinforcements arrive, the Red Sox are a team that needs to be better in a number of areas if they're to get off this oft-steep roller coaster that keeps bringing them back to the middle of the road.

“It was an up and down first half, that's for sure,” Cody Ross said. “We played really poorly at times, and played really good at times. We really couldn't be consistent.”

Beginning right there, here's a glimpse at what doomed the Sox on the field in the first half — and where they need improvement in the second:

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INCONSISTENCY: In the 2007 season, when they spent 172 days in first place and won the World Series, the Red Sox never lost as many as five games in a row and had just three winning streaks of at least that long. The key was consistency — which has been painfully lacking this year. Boston started the first half losing five of six, then ended it losing six of seven, and already they've had three five-game losing skids as well as three runs where they won five straight. They can't seem to find the even flow that makes for successful baseball.

“It's gone up and down so much,” Sweeney said. “We'd get on a winning streak, then a losing streak, then a winning streak — so we've just got to put it all together, and hopefully we'll be right there at the end.”

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SCORING: A major factor in the inconsistency has been a deceptively average offense. Overall, the Sox rank second in the American League in scoring with five runs per tilt; however, their offensive median is just four runs per game, which means they're statistically as likely to score less than four runs as they are to score four or more. That suggests a big chunk of their runs has come in bunches, and doesn't pair well with a pitching staff sporting a 4.22 earned run average.

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ENERGY: The Yankees' early explosions last weekend brought to light the fact that Boston's first-inning ERA is second-worst in the AL, but slow starts haven't been exclusive to the pitchers. The Sox have been outscored 69-50 in the opening frame this season, and far too often have lollygagged through two or three lethargic innings before seemingly starting to compete.

“I think we've got to look ourselves in the mirror and play with more energy,” Ross said Sunday night. “We got our butts kicked.”

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TIMING: Some of the Sox' issues have been the result of bad — call it unlucky, even — timing. And it's been true from the start. Not a couple days after making the ill-fated decision to let Daniel Bard try starting, closer Andrew Bailey learned he needed thumb surgery. Cody Ross homered in back-to-back games, then missed a month with a foot injury. Kevin Youkilis was traded, and a week later Will Middlebrooks' hamstring started balking.

Then, adding insult to all the injuries, Youkilis got hot as soon as he reached Chicago — where he needed just 13 games to drive in as many runs as he did in 42 games with Boston, and in that same span pushed his on-base plus slugging (.767) past both Adrian Gonzalez (.745) and Dustin Pedroia (.726).

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UNDERPRODUCING STARS: Including Youkilis, Gonzalez and Pedroia, the Sox have five players on their roster who've received MVP votes in the past three years (Ellsbury and Crawford are the others). Through 86 games, those five stars have yielded a grand total of 16 homers, 95 RBIs, a .265 average, a .324 on-base percentage, a .398 slugging, and a .722 OPS — the last two rating worse than the typical AL player.

That from a quintet that, when building the team this winter, would've likely represented five of the top six hitters in the everyday lineup.

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TOP OF THE ROTATION: The stars of Boston's pitching staff have been arguably more culpable than their batting counterparts. Jon Lester's 4.49 ERA is more than a run higher than he's posted in any full big-league season, while Josh Beckett's 4.43 more than a run and a half worse than he finished last year. Accordingly the team is 12-20 in games the two supposed aces start — and though Buchholz is personally 8-2, the AL's fourth-worst ERA (5.53) spares him little blame.

“Horse(bleep) first half,” Lester said. “I can only speak for myself — uncharted water for me. Just got to keep grinding it out. Can't give up. I just got to keep working. That's all I can control. Showing up every day, working hard, things are going to turn around.”

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ELLSBURY: Sox center fielders have scored fewer runs (35), and have a lower batting average (.243) and a lower OPS (.704) than any other AL team at the position. Meanwhile, Boston's leadoff hitters have scored the fourth-fewest runs (47) with the third-worst on-base percentage (.309) and second-fewest walks (25).

Fortunately, the guy who can solve all that in one transaction could return this weekend.

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PLAYING WELL vs. GOOD TEAMS: Boston's 26-36 mark against teams at .500 or better is the fourth-worst in the American League, and that needs to get significantly better if the Sox' standing is to do the same, since 65 of their 76 remaining games are against that caliber — including each of the 19 they'll play through Aug. 1.

By then, we may well know if this season is on the path to an F.

Dave D'Onofrio covers the Red Sox for the New Hampshire Union Leader and Sunday News. His e-mail address is ddonof13@gmail.com.