Wagner’s success a bullpen rarity

Hitters might be having a field day against Aaron Heilman, but they don’t know what to make of Billy Wagner so far this season. Sporting a new pitching style and a couple of new pitches, one of the most effective closers in baseball history was unhittable –- literally -– through the Mets’ first 21 games.

Despite pitching four games in a row during one recent stretch, Wagner had not allowed a hit, much less a run, in eight ninth-inning appearances while picking up four saves along the way.

“Honestly, I’ve gotten lucky with a lot of pitches,” Wagner said before tonight’s opener of a three-game home series with the Braves. “I’ve gotten away with a lot of stuff. I just try to stay with the plan, throw strikes and make them get themselves out.”

It’s a far cry from the Wagner everyone saw at the end of last season, when back spasms played a big role in him blowing three saves from Aug. 10 and drawing boobirds at Shea Stadium for the first time since becoming a Met in 2006.

Wagner is healthy again, as evidenced by a fastball that’s back in the mid-90 mph range, and the Mets couldn’t be more impressed.

“He’s been going after hitters, throwing strikes and hitting spots,” Willie Randolph said. “He’s been great. Billy is still one of the better closers in the game, and I don’t expect anything less than that when he goes in there.”

Wagner attributes much of his early success to a new weapon in his arsenal -– throwing from the wind-up. It is yet another way to stay ahead of the opposition at age 36.

Wagner went to the wind-up in spring training and could sense the positive results almost immediately.

“A lot of my success is coming from [using the wind-up],’’ he said. “It gives other teams a different look, and they’re not able to pick up the ball as well as they could in the past. It’s been a good move for me.”

Wagner also added a curveball in the spring and felt he was able to throw it effectively, giving him a fourth pitch to go along with his change-up, slider and trademark fastball.

Although Wagner understandably is relying on his fastball, the entire package –- new pitch and new approach -– is baffling the opposition in the early going. Wagner had not faced more than four batters in any appearance through Wednesday.

“I’ve gotten ahead with my fastball and gotten early swings, which is letting me have quick innings,” Wagner said. “You don’t have to go through a lot of pitches when you’re fastball is working, and my fastball has been working.”

Because Wagner has been working so efficiently, Randolph hasn’t been afraid to ride him often as the left-hander closes in on Jeff Reardon for sixth place on the all-time career saves list.

Wagner worked four games in a row at the end of last week, adding three saves to bring his current total to 362 – five shy of Reardon. Randolph said he doesn’t fear using Wagner too much.

“Billy isn’t like [the Padres’ Trevor] Hoffman, where you have to watch him,” Randolph said. “He’s still young and in great shape. He’s a horse, so I don’t think about conserving him or wondering if he’s going to be strong in the end.”

Wagner says Randolph shouldn’t worry about over-extending him.

“It’s the nature of the game for a closer, and I’m up to the task,” he said. “I’m not having to grind, so I’m able to go three or four days in a row with no problem.”

At least so far, no runs and no hits, either.