KANSAS CITY - Because he had been quite effective at his job, successfully recording saves in nine of his first 10 opportunities this season, the Nationals had been able to overlook the other red flags attached to Jonathan Papelbon’s name.

But on nights when Papelbon isn’t effective - and he certainly wasn’t tonight in blowing a two-run lead in the bottom of the ninth and sending the Nationals to a disheartening, 7-6 loss to the Royals - it becomes much easier to point out his flaws.

And that doesn’t even include his non-baseball flaws, which have been the source of ongoing angst for some time now.

No, strictly in a baseball sense, Papelbon’s biggest flaw is a simple one: He doesn’t miss very many bats anymore. He used to, back in his days as a World Series winning closer for the Red Sox when he struck out nearly 30 percent of all batters he faced. And even during his first three years with the Phillies, when that rate fell but only to 26.6 percent.

Since joining the Nationals, that rate has plummeted to 16.7 percent. Papelbon used to strike out three of every 10 batters he faced. He now strikes out just one of every six.

“He’s our closer. There’s a lot of closers that don’t miss bats,” manager Dusty Baker said. “It’s a matter of location, more than anything.”

That’s not entirely true. The only closer with at least 20 saves over the last two seasons and a lower strikeout rate than Papelbon is Arizona’s Brad Ziegler, a unique case given his sidearm throwing motion.

There are, of course, plenty of ways to retire major league hitters. And plenty of big league pitchers, including relievers, have been quite successful at inducing weak contact and recording outs that way.

Papelbon, though, isn’t inducing weak contact. Of the five hits he allowed in tonight’s blown save, four were well-struck. Alex Gordon’s leadoff single would have been a weak grounder to short had the Nationals infield not been shifted around to the right side. But Salvador Perez’s single left his bat at 95 mph. Mike Moustakas’ game-tying single was a 107-mph bullet up the middle. Alcides Escobar’s two-out single was hit at 91 mph. And then Lorenzo Cain’s game-winning drive past a diving Michael A. Taylor in left-center had an exit velocity of 103 mph.

That’s hard contact, and it’s something opposing hitters have been doing to Papelbon for the last month, even when he was successfully converting saves.

“They’re all big league hitters. You’ve got to be able to get them out,” Papelbon said, later explaining his struggles on this night in simple terms: “Execution. Execution. I didn’t execute some pitches. That’s what it boils down to: Execution.”

Credit, of course, must be given to a Royals lineup that won the World Series last fall with late rallies just like this. They turned it into an art form, refusing to strike out, always delivering a key hit when they needed it most.

“We know they have a good team,” catcher Wilson Ramos said. “We have to make sure we just execute pitches. We have been doing that, but unfortunately tonight was not one of them.”

“That’s what they do,” Baker said. “That’s what they do in this ballpark. And they certainly know how to come back, because I’ve seen them come back many, many times. Boy, that’s real tough. But tomorrow shows what kind of character we have after a tough loss.”

The Nationals collectively have shown some strong character early this season. After getting swept by the surprising Phillies at home last week, they hit the road for perhaps their toughest trip of the year and proceeded to beat the Cardinals and Royals four straight, then took a 6-4 lead into the bottom of the ninth tonight.

One bad ninth inning, though, can make a lot of positive developments disappear into the night. It happened here tonight. Now the Nationals have to hope it doesn’t happen too many more times with their combustible closer.

“Pap’s been good. He’s been very good,” Baker said. “Nothing to say, they just took that game from us.”