The Nationals got Casey Janssen today, the same Casey Janssen that did a great job of getting the most out of his skill set before last year. Without an overpowering arsenal, he hung with the best in his craft. Though the contract wasn’t expensive, it still represents a hope that Janssen can return to those days.

Ken Rosenthal reports that the deal is for one year and $5 million, but contains a mutual option. Last year, the pitcher battled back and shoulder soreness to have his worst year in the past five.

But even before his 2014 season, Janssen was… a bit different. When we think of swing-and-miss stuff, we don’t think of his 90 mph fourseam paired with a good cutter and a loopy curve. And for good reason. From 2011-2013, Janssen outperformed his swinging strike stuff.

Here are qualified relievers, mapped by their strikeout percentage against their swinging strike percentage. Janssen (25.2% strikeouts, 8.7% swinging strikes) is highlighted.

It’s no great mystery how he does it, perhaps. The pitcher himself admitted that command was the key to his success, and over the time frame shown above, he had the 14th-best walk percentage (5.6%). In the top 15 are other names without big fastballs: Sergio Romo, Jonathan Papelbon, LaTroy Hawkins, Rafael Betancourt and Huston Street.

Then again, last year Janssen still had a good walk rate and couldn’t strike anyone out. You can’t be all command, and the injuries did cost him in velocity and movement. His slider and curve had career-low horizontal movements, and his slider, curve, and sinker all lost about an inch of drop. And he lost a mph of fastball velocity while his other pitches held steady, meaning that his velocities converged. Hopefully a lighter workload and an offseason of rehab has fixed what ailed him.

The Nationals traded away a pitcher in Tyler Clippard that was unique for his ability to induce infield fly balls. In Casey Janssen, they signed a replacement reliever that was better than most at getting strikeouts from mellow stuff, and he’ll cost half as much.