Matt Thornton. (Photo by Greg Fiume/Getty Images)

Since joining the Nationals on Aug. 6, Matt Thornton has capably filled the role that he was acquired to do. The veteran left-handed reliever has retired 18 of the 21 batters he has faced, and those three baserunners didn’t score. He throws heat — a fastball consistently clocked around 95-96 mph — and has fit seamlessly into a Nationals bullpen that, although one of the best in baseball, has shown signs lately of fatigue.

“He throws so hard but he throws strikes,” Manager Matt Williams said. “And they’re down strikes. They’re low strikes. He’s aggressive. He’s gonna throw it over the plate and uses his fastball to both sides and he’s not afraid to throw it. That’s what’s impressed me. That he’s been able to face righties and lefties, and down strikes and get ahead. At 96, 97 mph, that’s important. If you go strike one, he’s really effective.”

Before the Nationals picked him on a waiver claim from the New York Yankees, Thornton felt like he was throwing as well as he had in a while. After the all-star break, he made minor tweaks to his mechanics that, he said, helped his tempo and arm motion on the mound. It helped him fine-tune pitches to both sides on the plate to right and left-handed batters.

“I feel good right now,” he said. “I’m healthy. Just going out there and attacking hitters with confidence.”

And with experience.  Thornton, 37, is in his 11th major league season. For four or five years, he attacked right-handed batters inside and left-handed batters away. But he made a concentrated effort to do the opposite this season: attack right-handed batters away and left-handed batters inside.  Thornton feels like it has helped his pitching.

In recent seasons, including in New York, Thornton was used as a left-handed specialist. But as a matter of personal pride, he felt like he could still get right-handed batters out. The Nationals acquired him to pitch full innings and face left-handers. He has held right-handers to a .240 average in his career and left-handers to a .233 average. Williams has used him to get out of other pitchers’ jams and face hitters from both sides of the plate.

“I’ve enjoyed the full inning, honestly,” Thornton said. “I’m game for whatever the team needs me to do. … I’ve never thought of myself as just a lefty specialist and I’ll do whatever the team needs me to do. And if that’s what Matt needs me to do, face lefties, that’s fine. I’ve enjoyed getting a full inning of work and having that on my shoulders.”

Another change that has helped is Thornton’s reliance on his splitter. Earlier in the season, his main secondary pitch, his slider, got hit more than he liked so he started using the splitter more. The 88-mph splitter dips late in the strike zone and gets groundballs, broken bats and strikeouts. Thornton said his splitter is like a change-up and can get swings and misses when it is sharp.

“My split has been a huge pitch for me,” he said. “… I still throw my slider when I need to but I haven’t gotten in that situation. I’ve gotten ahead with my fastball. A well-located fastball, I believe, is still the best pitch in baseball. So I’m worried on location with my fastball and driving it through the strike zone and making them put it in play.”

Being new to the National League could be seen as a disadvantage but Thornton thinks it has been a benefit so far.

“Obviously they have scouting reports now so it’s not a mystery, but at the same time seeing a hitter for the first time and them seeing me for the first time is something new and they don’t have a gauge of me quite yet,” he said. “I’m trying to take advantage of that right now and continue to help the team.”