To understand what the Nats are getting, it's important to know the road that Lidge has traveled. It has been a mixture of pain and celebration, of frustration and accomplishment. At 35, he has seen just about all there is to see.
Lidge's easygoing demeanor belies his strength and self-confidence. No one passes the tests he has passed unless there's some real steel in his core. Even better, he's one of those people liked by virtually everyone who knows him.
Lidge's career almost never happened. At one point in the Minor Leagues, he was so frustrated by his inability to stay healthy that he returned home to Denver, enrolled in a junior college and prepared for the next chapter of his life.
Tim Purpura, who was then the Astros' farm director, sat down with Lidge and pleaded with him not to give up. One of Purpura's points came from a page of the San Francisco Giants' media guide, which detailed the long, tough path that Robb Nen took to the big leagues.
"He went through everything you did," Purpura told Lidge, "and he ended up having a great career."
Houston drafted Lidge in the first round of the 1998 First-Year Player Draft out of Notre Dame. He had a blazing fastball and a slider that was about as devastating as any pitch ever thrown in the big leagues.
But Lidge's problem was staying on the field. One year it was the elbow. Another it was a knee. And just when he'd get healthy again and seem to be back on the right track, something else would break or tear.
By the time Purpura talked Lidge back into a uniform, time was running out. When the Astros went to Spring Training in 2003, Lidge was 26 years old, which is quite old for the Minor Leagues.
It was then that Houston general manager Gerry Hunsicker decided that Lidge would open the season in the big leagues, even though he had less than a season of Triple-A ball under his belt.
"It's time to find out," Hunsicker said.
Hunsicker gave up on the idea of Lidge being a starting pitcher and inserted him in his bullpen in front of Billy Wagner and Octavio Dotel. Instead of trying to perfect an offspeed pitch, Lidge only had to polish his fastball/slider combination.
Lidge had found his niche. Over the next three seasons, he would be as dominant as any reliever in the game, and made the transition from pitching the seventh inning to the eighth to, finally, the ninth.
In those three seasons between 2003-05, Lidge saved 72 games, had a 2.29 ERA and averaged 12.8 strikeouts per nine innings. At times, hitters would approach Astros first baseman Jeff Bagwell and offer a simple scouting report.
"Oh my God," they'd say.
During the 2004 playoffs, Lidge compiled the following line: seven games, 12 1/3 innings, five hits, one earned run, three walks and 20 strikeouts.
Lidge ran into trouble during the 2005 playoffs when Albert Pujols hit a monstrous home run to win Game 5 of the National League Championship Series for the Cardinals. It seemed to be one blip on another otherwise perfect career resume, and on the flight to St. Louis after the game, Houston catcher Brad Ausmus asked the pilot to make an announcement at 30,000 feet.
"If you look out the left side of the plane, you'll see Albert Pujols' home run ball," he said.
Everyone laughed because, well, no one believed anything fundamental had changed. But it had.
Lidge suddenly lost command of the strike zone and some bite on his slider. Two tortuous years followed. He had meltdowns on the mound and lost his closer's role a couple of times. He endured anyway, kept trying and never gave up.
Some wondered if Lidge was injured. Others thought he might be tipping his pitches. For a time, Lidge believed that was the problem. He came to this conclusion when a player whom the Astros acquired told Lidge, "Hey, we had your pitches last season."
Lidge stopped tipping his pitches, but never regained the consistency and dominance of those first seasons. He became the object of tough criticism on the radio and in the newspapers, and while he never showed that he was bothered by any of it, the environment wasn't exactly conducive to success.
Perhaps the best indication of how highly regarded Lidge was came during those times when some of those that knew him best had trouble watching him pitch. They simply couldn't stand to watch him struggle.
After the 2007 season, Astros general manager Ed Wade did Lidge a huge favor and traded him to the Phillies. There, Lidge reset his career and regained command of his fastball, along with some of the necessary swagger to challenge hitters.
Lidge converted 48 straight save chances in 2008 and got the final out of the World Series. In dropping to his knees and looking to the heavens in that spectacular moment, he gave the City of Brotherly Love its lasting image of a championship season.
"I wouldn't change anything in my career," he said that night.
In the three seasons since, Lidge has had two more elbow operations and another on his knee. When he returned last season, he pitched well, but lost the closer's job to Ryan Madson.
With Drew Storen in place to pitch the ninth, Lidge will be asked to handle the innings in front of him. When he has been healthy, he has continued to pitch at a high level. But the truth is, the Nationals have no idea what they're getting.
Their investment is a relatively modest $1 million. Lidge's fastball hovers around 90 mph these days, but his slider is still plenty good enough. For the people who know him and root for him, it's a happy, happy day to see him catch on with one of baseball's rising teams. Lidge has already had far more of a career than he once imagined, and here's hoping that there's plenty more to come.
Richard Justice is a columnist for MLB.com. Read his blog, Justice4U. This story was not subject to the approval of Major League Baseball or its clubs.