Tyler Clippard does not know, exactly, how he came to pitch the way he does. Nothing about what Clippard does on the mound, as a reliever for the Washington Nationals, looks quite like what any other pitcher does. He strides forward as if stepping over a hurdle. He pauses slightly. His shoulders tilt upward as he cocks his right hand behind his head and shows the batter his left forearm. “He’s throwing elbows and [butt] at you,” teammate and former strikeout victim Matt Stairs says. “It’s not a fun at-bat.”

It’s what always felt right. It helps that Clippard is naturally flexible — he discovered he could do the splits easily when he signed up as a 6-year-old in Tampa for taekwondo classes. Each year at spring training, Clippard scores at the extreme end of team-mandated flexibility tests. His teammates call him Gumby.

Clippard will spend Tuesday night in Phoenix, showing off the herky-jerky delivery that, four years after the New York Yankees traded him and three years after the Nationals shipped him to the bullpen, has made him a strikeout machine and a National League all-star. Clippard has reached the top of his profession because he assessed what set him apart and dismissed any external forces trying to change him. He knew what felt right.

Clippard long ago learned to embrace what made him different, coolly self-confident and wonderfully oblivious. On the day of his major league debut, Clippard sat in the Yankees’ clubhouse and wore a T-shirt he had won in a baseball tournament at 16. He doesn’t wear glasses off the field, but he wears protective goggles on the mound. For years, he chose for his warmup music the goofy alternative rock song “Peaches.”

“Me being outside the box a little bit I think is a beneficial thing,” Clippard said. “I like it. I relish it. I don’t want to be in the cookie-cutter category of mechanics and delivery.”

In a vacuum, the quality of Clippard’s pitches would make him, maybe, a fringe major leaguer. He throws his fastball between 92 and 94 mph, hardly overpowering velocity for a reliever. He pairs it with an above-average change-up and a curveball he rarely uses. The manner in which he unleashes those pitches, though, makes him one of the most dominating relievers in baseball.

“If everybody threw like Tyler,” his father, Bob Clippard, said, “he wouldn’t be effective.”

Not as fast as it looks

Clippard’s funky delivery includes a brief pause, which throws off a hitter’s most crucial asset — his timing. Clippard hides the ball with his arm, shielding his release point with his glove. Because of the way his shoulders point up, not down like most pitchers, his fastball stays on an even plane. It does not rise, but it seems to. He uses precisely the same motion for his change-up, which seems, to a hitter, to disappear once it reaches the plate.

Each singular tic would provide an advantage. In combination, the qualities of Clippard’s motion create a devilish optical illusion. In the minor leagues, hitters would reach second base and ask infielders how hard Clippard threw. The answer was 90 mph. They replied that it seemed like 96, maybe 97.

“I think when it comes to release point and the positions that you get in before you release the ball, everyone is very similar,” Clippard said. “I think I get into that position just like everyone else. Obviously, little things might look a little different. My frame, my body and the way it moves is different than other people. So that plays a factor.”

Bob Clippard provides mental support for his son these days, calling him after great games and blown leads. He coached him growing up. He bought a book on pitching mechanics, but he only incorporated mechanics into Clippard’s natural motion. He put Clippard through various drills, like stepping over a plank to lengthen his stride, but he never fundamentally changed him.

“My dad never tried to correct me,” Clippard said. “He just let my natural delivery take over, and then we worked from there. I don’t know if that was on purpose or not, but it worked out.”

Clippard excelled in youth baseball games, playing on three travel teams a year in baseball-crazy Florida against elite competition. Getting noticed still did not come easy. He was skinny, he threw funny and he did not light up radar guns. When he entered high school, Bob Clippard said, he thought maybe he could play golf professionally.

“He was always the number three guy or not even on the radar,” Bob Clippard said. “He never looked like the guy. You look at him, he doesn’t look like he’d be able to do what he does.”

Clippard starting breaking 90 mph by his senior year of high school, and the Yankees drafted him in the ninth round. He rose quickly through their system and in 2007 a rash of injuries necessitated a sudden call-up. He made his major league debut at 22, before more than 56,000 people at Shea Stadium, for the most venerated franchise in American sports. He pitched six innings, allowed one run and won.

“We were calling up everybody under the sun because we had injuries,” Yankees General Manager Brian Cashman said. “It was a great performance. He made a name for himself.”

Clippard made five more starts before the Yankees’ star-studded staff got healthy, and he returned to the minors. Once he left the majors, though, his career hit a speed bump. He experienced his first sustained struggles, and by the end of the year the Yankees had demoted him to Class AA. Clippard’s head spun. He had made the majors, but he no longer sensed he was a prospect.

He was right. The Yankees viewed him then, Cashman said, as “a fringy starter.” Cashman did not see Clippard’s mechanics translating to the bullpen, but he thought he could turn him into a useful reliever.

“We thought that he had pretty complicated delivery; we felt it was going to stay complicated,” Cashman said. “We had some questions there. . . . I certainly didn’t see this coming. I’m happy for him. He’s a good kid.”

Shift to the bullpen

In December 2007, the Yankees traded Clippard to the Nationals for reliever Jonathan Albaladejo. (“He had some filthy stuff,” Cashman said of Albaladejo, who is pitching in Japan now.)

“It was a motivational breath of fresh air,” Clippard said. “A new start, a new beginning. I enjoyed it. I was happy about it.”

Clippard made two major league starts in 2008, but by the following spring training Nationals pitching coach Steve McCatty had come to believe Clippard translated better out of the bullpen. Batters, McCatty figured, wouldn’t get a second chance to figure him out, his fastball would play up, he would present a radical change of pace. He sat Clippard down and explained that his career as a starter had ended. He was a reliever now.

“I was mad,” Clippard said. “I was not happy about it.”

Fuming, Clippard called his father. Bob Clippard listened, then asked his son, “You got a job, right?”

There was a long pause.

“You’re right,” Clippard said. “I’m still playing baseball.”

Soon, Clippard embraced pitching out of the bullpen. He started the year at AAA Syracuse but knew it was a matter of time before he reached Washington. By the end of the year, he had become indispensable. In 2010, he gained notice as a dominant setup man. This year, he became an all-star.

Tuesday night in Phoenix, Clippard is going to hear his name over the loudspeakers and tip his cap, validation that he was right not to change. As a Yankees farmhand, Andy Pettitte had walked past him in a bullpen one spring training morning and asked, “Why do you throw like that?” Clippard has shown why, proving that different is not wrong.