OAKLAND -- Many baseball people refer to baserunners as “traffic.” By that definition, the Mariners generated enough traffic to extend rush hour past midnight in any major city.

Unfortunately for the Mariners, a remarkably small portion of their commuters reached their destination Friday night -- in this case, home plate. Seattle remained mostly stalled despite mounting rally after rally in a 6-2 loss to the A’s.

• Box score

The Mariners outhit the A’s, 10 to eight, but they left at least one runner on base in every inning except for the sixth and eighth. And even in the sixth, Mitch Haniger drew a leadoff walk before being picked off. Seattle ultimately stranded a season-high 15 runners.

Manager Scott Servais used the word of the day to summarize the Mariners’ performance. They had, he said, “a lot of opportunities with traffic on base. We just couldn’t get a hit.”

Three times, including the ninth inning, the Mariners left the bases loaded, a situation in which they had batted .356 entering Friday, third-best in MLB.

“That was the key to the game today. Not giving up the big hit when there were guys on the bases,” A’s manager Bob Melvin said. “It’s difficult to do and, we only end up giving up two runs. Wouldn’t have won the game without that.”

Citing instances of solid contact that resulted in outs, Haniger observed that all the Mariners can do is keep swinging.

“You have to have good at-bats and hit the ball hard,” Haniger said. “Everything else is out of our control.”

The lack of offensive support doomed Mariners starter Wade LeBlanc (2-2, 7.33 ERA), who surrendered four runs and five hits in five innings.

Making his second start since returning from a strained right oblique, LeBlanc faced the minimum nine batters through three innings. But he crumbled in the fourth inning, when Matt Olson and Mark Canha combined to hit back-to-back homers that accounted for the A’s four runs in that frame.

LeBlanc observed that what’s good for the hitter is also good for the pitcher. “I have to be aggressive,” he said. “But I have to stay in the strike zone.”