Stephen Strasburg’s been in the news lately for playing catch. It’s still unclear whether he’ll pitch again this season. Given that the Nationals are just a few weeks away from postseason baseball, and given that Joe Ross just returned from having missed 10 weeks with a shoulder injury and is currently working on a limited pitch count, it’s not an ideal situation for Washington’s rotation. Gio Gonzalez is having his worst season in six years by ERA and FIP, and Lucas Giolito was unable to provide the shot in the arm that many had hoped.

And so, the comfort of having the always stellar Max Scherzer notwithstanding, anyone invested in the success of the Nationals is currently thinking what I’m sure they all expected they would in the spring: thank goodness we have Tanner Roark.

One year after having a near-replacement-level season in the bullpen for Washington, Roark might just be their saving grace. He shut out the red-hot Mets over seven innings in his last start, lowering his season ERA to 2.75. He’s been a top-five pitcher in the National League by RA9-WAR, within a win of Scherzer’s spot at the top of the leaderboard.

He’s essentially been Washington’s version of Kyle Hendricks: a sinkerballing right-hander, never thought to have a high ceiling, who simply decided to stop allowing runs despite possessing neither premium velocity nor readily apparent plus stuff. Like Hendricks, it’s difficult to understand, on the surface, how Roark is doing what he’s doing. With Scherzer, one must look no further than the strikeout rate to find the root of the success. It’s a little harder to fathom with a guy like Roark.

But you start with the arsenal. It runs five deep, and it’s remarkable in its own right. Sure, Roark throws 92 and his swinging strike rate is below league average. But according to our PITCHf/x pitch values, Roark’s sinker has been arguably the most valuable in baseball, at 14 runs above average. The changeup is in the top-five. The curveball’s been a plus. The slider’s been a few runs above average, and the four-seamer has, too. Not many pitchers can command five offerings at all. Even fewer can do it well:

Pitchers with Five Above-Average Pitches Name wFA wFT wFC wSL wCU wCH TOTAL Johnny Cueto 12.6 6.1 3.1 4.4 0.5 5.3 6 Tanner Roark 2.0 13.8 – 2.6 4.8 8.3 5 Madison Bumgarner 5.8 1.0 – 12.4 7.6 1.3 5 Jake Arrieta 10.9 20.1 – 1.1 3.2 0.3 5

That’s the full list of qualified starters who possess five or more above-average pitches this season, according to our pitch-type run values. Three aces and Tanner Roark. Hendricks isn’t far behind, checking in as one of the 14 pitchers with four. But here’s Roark, with five solid pitches, among which he doesn’t discriminate.

He’s liable to throw most any pitch in any count, but it’s the sinker that leads. He throws it nearly half the time, and the usage barely changes when Roark gets to two strikes. Most pitchers use the fastball to get ahead, and the breaking and offspeed to put batters away by getting them to chase. The way Roark puts batters away is by getting them not to swing at all. Roark’s 56 called third strikes rank sixth in baseball, and of those 56, the two-seam was responsible for 48.

The approach is clear:

It’s the Aaron Nola approach, racking up strikeouts by backdooring the two-seamer in on the hands of lefties or on the outer-edge of the plate against righties.

Roark certainly benefits from his catcher, Wilson Ramos , in this regard. Ramos has graded out as a solidly above-average receiver this season, generating eight runs of value by stealing strikes, according to Baseball Prospectus. Definitely, Ramos ought to earn some of the credit for all of Roark’s called third strikes. But most of it goes to Roark himself.

It’s Roark, after all, who generates the arm-side run on the two-seam while spotting it so consistently on the edge of the plate, getting batters to take and allow Ramos to work his receiving magic in the first place. Overall, Roark has run baseball’s third-lowest swing rate against this season, and it’s not because he’s working outside the zone; it’s because he’s gotten batters to take more pitches over the plate for strikes than all but four pitchers. The guy in first in that particular category? Hendricks.

Some of it’s got to be command. Some of it’s got to be deception. Some of it’s got to be keeping hitters off-balance with such an equal distribution of four-to-five above-average pitches. Perhaps that’s how they’ve each both gone about generating such soft contact, too. Hendricks leads the league in soft-contact rate, Roark ranks third. Another instructive way to look at this is to subtract hard-contact rate from soft-contact rate; avoiding hard hit balls is as much the goal as generating soft ones, after all.

Soft%-Hard%, qualified starters, 2016

Kyle Hendricks, +0.2% Tanner Roark, -0.9%

Hendricks is the only starter this year to generate more weak contact than hard, according to Baseball Info Solutions’ classifications. Roark is right behind him.

Knowing all this, when you look at the near one-run gap between Roark’s ERA and his FIP, thanks to his .277 BABIP allowed and 80% strand rate, it becomes a little easier to understand. Probably, Roark’s been the beneficiary of some good fortune this season. Then again, the .277 BABIP is near-equal the .275 mark he’s run over nearly 600 career innings. Ditto the strand rate. We’re about three full seasons worth of innings into Roark’s major-league career, and he’s got a 2.99 ERA, and while he maybe doesn’t have the peripherals to back that up, how important is having the process to back it up?

Tough to say. Is Roark probably pitching above his head right now? Yeah, probably. But each time he throws seven innings of shutout ball, the weight of importance from peripherals to process seems to shift. Having the five above-average pitches, and the command of them all, and the deception or whatever it is that gets batters to take strike after strike, and the ability to keep batters off-balance or whatever it is that gets all that soft contact, it all adds up to quell some of the concerns that come with the lack of plus stuff.

Who could’ve thought at the start of the year that a comparison to Kyle Hendricks, Cy Young candidate (frontrunner?) would come as such a compliment? Who could’ve thought that the Nationals might be heading into October with Tanner Roark as their No. 2 starter, and felt perfectly fine about it?