July 21, 2014 at 1:00 am

Tigers own eighth inning, thanks to Joba Chamberlain

Tigers pitcher Joba Chamberlain, giving a thumbs-up after signing a ball for Jason Gabbard, 11, right, of Allen Park before a game on June 4, has a 1.42 earned-run average in 34 eighth-inning appearances. (Robin Buckson / Detroit News)

Detroit — It’s a weird stat about a weird bullpen. But the Tigers are actually the best in a category.

Thanks to Joba Chamberlain, the Tigers have the best eighth-inning earned-run average in the American League at 2.27.

The A’s are second, and it’s not close at 2.48.

Not bad, but here’s the flip side.

The Tigers have the worst ninth-inning ERA in the majors at 6.37, and that’s not close, either.

The Angels, who like the Tigers would be a playoff team if the season ended today, are next-to-worst in the majors with a 5.61 ninth-inning ERA.

The 1.18 by the Nationals, by the way, is the best ninth-inning ERA in the majors.

Let’s, however, separate the eighth from the ninth.

If you wondering who has eighth-inning problems, look no further than the White Sox and Rangers, who are second-to-last and last in the league at 5.36 and 5.69, respectively.

It’s one of the many reasons the White Sox have failed to contend and, in the case of the Rangers, one of the many reasons they are having a miserable season.

The eighth inning can be removed from consideration of the Tigers bullpen problems, though. Chamberlain has made it one of the strengths of the team.

In fact, his ERA for the eighth is 1.42 in 34 appearances. And, accordingly, the Tigers heaped praise on him after he contributed another scoreless inning in a 5-1 sweep-avoiding victory over the Indians on Sunday.

“He’s been the one piece that’s been consistent all year,” manager Brad Ausmus said. “We get to the eighth inning, it’s Joba.

“If we have a short lead or if it’s a tie game, sometimes even a one-run deficit, it’s Joba, and the vast majority of the time, he’s done the job extremely well.”

The starters appreciate him, too.

“Every time he comes into a game, it seems he goes 1-2-3 pretty easily,” said Drew Smyly, the winner in the series finale. “He’s been amazing. He’s had like one bad game all season, and that’s tough to do coming out of the bullpen.”

That one bad game was June 8 against Boston at Comerica Park. Chamberlain gave up three runs, but it was in the ninth inning, not in the eighth, of a 5-3 loss.

Chamberlain has not been asked to pitch a ninth inning since, and in his last 14 appearances, he has a 0.73 ERA.

“You have to have a short-term memory as a relief pitcher,” he said after Sunday’s victory. “You’re only as good as your last outing.

“I don’t care when I pitch as long as I get a chance to pitch. But I’m fortunate enough to know when to get ready, so you just have to maintain a mindset and get locked in.”

The starters have done a better overall job than the bullpen. The Tigers’ ERA from innings 1-6 is fifth in the AL at 3.74. They even have the best third-inning ERA in the majors at 1.99.

But after the sixth inning, even with Chamberlain’s effectiveness, the Tigers are 13th in the league (27th in the majors) at 4.56.

And their opponents’ batting average of .270 after the sixth inning is the worst in the AL.

For measuring purposes between last and first, the A’s bullpen is the best in the AL after the sixth in both categories with a 2.71 ERA and a .214 batting average.

So there’s an obvious problem needing to be fixed, and the proof is in the stats. Numbers can be used to underscore subtle points, but in this case, the problem isn’t subtle.

The Tigers need bullpen help, the numbers merely backing up what fans already know to be true.

Chamberlain has done an outstanding job and has the right attitude about trade rumors.

When asked if he hears them, he said, “not unless you guys bring it up. I played in New York for seven years, so I haven’t read or watched anything. I learned quickly as far as that goes.”

But the Tigers still have a leaky bullpen that needs to be plugged. It’s why rumors have been rampant, and why, in all likelihood, they won’t go away.