Since 1999, however, while his role has remained the same, Isringhausen's style has changed dramatically. As late as 2002, he had a classic closer's repertoire: electric 96-mph fastball and a hard, power curveball. In recent years, he became a different animal entirely, taking a little off the heater and throwing a cut fastball much more often. Now he's making another transition as he tries to add a sinking two-seam fastball.
The curve is still there, and once in a long while he'll dial up the fastball. But Isringhausen sets up hitters these days, and occasionally he dabbles in a wide array of pitches -- a sinker to get hitters off his cutter, even a changeup here and there.
"I used to throw as hard as I can, and then throw curveballs here and there," said Isringhausen.
"And I got beat a lot more than I do now."
Isringhausen has pretty much always had the cutter as a third pitch, but it wasn't until 2002 that he began using it as a centerpiece of his arsenal, rather than a complementary offering. As his velocity dipped a bit, and pain in his shoulder restricted him, he began looking at other ways to get hitters out.
"Even my first year here, I was still throwing hard," he said. "Then the hip started hurting, the shoulder started hurting. It was when I was hurting I had to make up different things."
Pitching coach Dave Duncan makes it a point to emphasize that Isringhausen hasn't forsaken power. It's just that he has more to offer as well.
"I think he's still considered a power guy," said Duncan. "I think he's just more of a blend of power and pitching."
The past three years, Isringhausen has remained one of the game's better relievers while eschewing the typical approach. He worries less about the strikeout and more about quick outs. He had the best ground ball-fly ball ratio of his career in 2005.
That's thanks in large part to his cut fastball, which isn't on par with Mariano Rivera's but reaches the low 90s. Now, though, he's trying to take one more step. With hitters beginning to sit on that cutter, Isringhausen would like to throw a sinker more often, bearing in on right-handers.
"They just get up on top of the plate and look for a cutter away," he said. "Throw the ball in, hit a couple guys, move people off the plate. I'm not trying to hit people, but I'm going to throw the ball in there. I'll pick my spots."
Besides expanding his repertoire, Isringhausen has also become more sophisticated in his approach. In his early days relieving in Oakland, he basically had exactly one way to get hitters out. Now he tries to be cagier.
That means on some days, breaking out the four-seamer/curveball combination. Sometimes it means a steady diet of cutters. Sometimes it means a little of both. Mostly it means paying attention to hitters, and understanding that different hitters should be attacked in different ways.
"I think he's more conscious of trying to pitch to the weakness of the hitter rather than just going after everybody the same way," Duncan said. "That's pretty much what he did when he first came over."
As Isringhausen enters his eighth season pitching out of the bullpen, he's as healthy as he's been in a long time. He's savvier than ever. And he may be more prepared than ever before to retire hitters.
"I've got a great defense behind me, and I've been blessed with that the last few years," he said. "Throw the ball and let them hit it. Don't try to be cute and strike everybody out."