BALTIMORE -- What a long, weird first half it’s been for the Orioles’ bullpen. Tasked with covering more innings than all but two other teams in MLB, the Orioles’ relief corps was an early-season darling, endured a miserable May and shifted amid near-constant turnover through June and July.

Through it all, an odd dichotomy emerged: The O’s ‘pen entered play Friday night as baseball’s seventh-most valuable unit by FanGraphs' Wins Above Replacement, yet with the game’s sixth-worst collective ERA.

How does that happen? Volume plus inconsistency, the result of lots of innings, stretches of individual dominance and, more commonly, head-scratching struggles. Examples of the latter defined Friday night’s 12-1 loss to the White Sox at Camden Yards, where the Orioles watched a close game stretch into a laugher as their bullpen walked seven en route to allowing 10 runs.

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“That definitely affected the game, there is no doubt about it,” Orioles manager Brandon Hyde said of the walks. “It’s not a recipe to win.”

The primary culprits were Cole Sulser and Dillon Tate, who combined to issue five walks during Chicago’s four-run sixth. Tasked with keeping a 2-1 deficit tight, Sulser opened the sixth by walking Andrew Vaughn and Gavin Sheets. Hyde responded by calling on Tate, who allowed a two-run double to Tim Anderson after Seby Zavala’s sac bunt.

Tate then issued free passes to the next three batters, including Brian Goodwin with the bases loaded. An additional run scored on Adam Engel’s sac fly, and three more came off César Valdez in the seventh -- two after, you guessed it, a two-out walk. That ensured starter Jorge López’s MLB-leading 12th losing decision, this one opposite of a sharp and efficient Dallas Keuchel. López’s ERA is 5.95 through 18 starts.

“Tonight felt like déjà vu,” López said. “Physically, I don’t feel tired. Mentally maybe, to stay over, and over, and over at the same spot. It gets you down. But I’m a strong man. I have a family, and they give me strength.”

All told, the Orioles walked eight in what amounted to a slow-moving meltdown, the type of which has become more common for the club in recent weeks. Last week, the Orioles issued at least nine walks on back-to-back nights to the first-place Astros in Houston -- and won both games. The seven walks issued by Orioles relievers Friday tied for second most out of the bullpen in team history since 1954. They also did it on June 28 at Houston.

Friday was also Baltimore's ninth game this season with seven or more walks, fourth most among AL clubs. Five of those games have come in the past 2 1/2 weeks; since June 21, they own the AL’s second-highest team walk rate.

“I don’t know if fatigue is playing a factor for some of these guys,” Hyde said. “It would be understandable if it is. … We’re just a little inconsistent right now.”

Friday’s results were particularly discouraging for Sulser and Tate, who have recently shown signs of tangible progress. Tate’s velocity spiked during the O’s late-June series against the Blue Jays in Buffalo, N.Y., with Tate’s usually mid-90s sinker flirting with triple digits, per Statcast. Meanwhile, Sulser had quietly been Baltimore’s most consistent middle reliever over the past two months, pitching to a 2.74 ERA across May and June.

Sulser now owns a 3.09 ERA over 29 games and one of the four strikeout rates north of 30 percent in the O’s ‘pen. Tate is 0-3 with a 4.66 ERA in 28 games, all in middle relief. Still, both might be poised to assume larger roles later this month if Tanner Scott or Paul Fry are shopped, as expected, at the Trade Deadline.