(Katherine Frey/The Washington Post)

The Nationals reached the 100-game mark four games below .500. This is not what many — if any — had predicted. Pitching and defense have limited the opposition to 397 runs, but the offense has fallen short of expectations, and an even run differential.

The 368 runs produced at 2013’s century mark is clearly a disappointment. The number of injury days racked up by key pieces of the lineup is a big culprit. Davey Johnson has barely had a chance to run his standard lineup out there. And you can only say it does it now if you wink and pretend Anthony Rendon occupied the keystone in April.

With the hopes of improved performances by a healthier and intact group of hitters, I’ll certainly have something to look back at at the end of the regular season. For now I want to look ahead at the pitching side of the equation, with a brief detour into defense.

Without delving into things like zones, range, what’s a hard-hit ball, the most basic team defense metric is simply the rate at which batted balls in play are turned into outs. The Nats rank 12th in baseball with a .707 rate as of July 23. The Pirates are the best (.735) and the Astros the lowest (.690). Not a huge range, four extra outs per 100 balls in play. But it matters. Another consideration is the nature of the ballpark itself, which for various reasons (speed of infield surface, size of outfield) can impact the defensive efficiency of a club. When Baseball Prospectus takes this into account the Nationals drop to 16th, the Astros move up two spots (Colorado takes over the basement) and the Jolly Roger still flies.

With what appears to be a middle-of-the-pack defense, the Nationals staff has still managed to put up solid numbers. Good old-fashioned ERA (3.64) puts them sixth in the National League. When you take into account things like the ballpark, the defensive ratings and other contextual factors, at Baseball Prospectus (where I also work) we rate the Nats fourth in the NL in FRA (Fair Runs Against). This staff is as advertised, even with a few warts here and there.

When we look at individual pitchers it paints an interesting picture. We can compare stats like ERA and FRA to FIP (fielding independent pitching) to start and suss out what guys are getting good (or bad) luck. Those guys could very well be in for a change in performance, or at least outcomes as traditionally measured. Relief pitchers are notoriously mercurial, so we’ll start with the main guys in the bullpen who have picked up over 40 innings.

The guy with the glistening ERA is usually the guy with the regression target on his back. In D.C. that target rides the back of Tyler Clippard. No one would expect his 1.85 ERA to last. How big of a correction is the question. FIP rates his year-to-date at a reasonable 3.22 but FRA takes him up to 3.76. His ERA is likely due to work its way up into the 2’s over the next few weeks. Nothing scary, but there’s not much reason to think Clippard can continue to avoid earned runs like he has.

The closer, Rafael Soriano, is also a candidate for some regression. Perhaps not as many chances as desired, but he’s converting saves at a solid rate — 86 percent is what you should expect from most closers. Soriano has posted a 2.36 ERA, which seems to be a fitting number for a closer. FIP (3.35) and FRA (3.56) are sending us a signal, that his batted balls may be due to find more of the holes in his defense. Nothing that rings any alarm bells, as Soriano sometimes seems to be pitching better than his numbers would suggest. And even a movement upward in his ERA wouldn’t necessarily mean he’ll blow substantially more saves.

Here’s some good news, not as if that was bad news before, but here it is. Drew Storen has pitched better than his record suggests. That 4.83 ERA is scary, particularly for a reliever, but FRA has him at a more modest 4.18 and FIP goes all the way to 3.82. Craig Stammen, the fourth reliever with more than 40 innings to date, looks to be due for more of the same. His 3.81 ERA is virtually identical to his 3.80 FRA, and his FIP is a tidy 3.10.

These four relievers, as a whole, aren’t going to look much different than they do now when we look back in September. One can also hope that there’s some upside in the defense that is now healthier than it has been all year. That could take some of the bite out of the regression FRA is hinting at, but straight-up FIP may be misleading.

Dan Haren‘s season has not gone as hoped. The target of much fan ire happens to be a candidate for mild improvement. His FIP is full run better than his ERA (4.76 to 5.79). Haren’s FRA is still above five (5.20) which confirms what we’ve all seen. He’s not pitched well, and it isn’t luck or defense to blame. Just like the relievers with the two-ish ERAs, starters with bloated ERAs also regress towards the mean–so they get/look better as time passes. Haren is the fifth starter, so this isn’t a crisis.

The big three of Jordan Zimmermann, Gio Gonzalez and Stephen Strasburg all have fancy ERAs (3.01, 2.89 and 2.97 respectively). FIP loves them, too (3.26, 3.36, 3.37). As has been a theme, FRA has cast a skeptical eye. Conventional wisdom would probably tell you a guy with Strasburg’s stuff is not too likely to cast a 3-ish ERA as a mirage. FRA marks him down for a 4.26, knocking him back well past Ross Detwiler (3.66). This seems to raise more questions than it answers. FRA is meant to give a different perspective than FIP does, but this disagreement seems large. For the other Nationals starters FIP and FRA tend to be in closer agreement. Zimmermann’s FRA of 3.86 is more than a half run above his FIP, Gio’s 3.48 is just a notch over his 3.36 and Detwiler brings a FIP of 3.64 to match his FRA of 3.66. His ERA is 4.04, hinting at some improvement to come.

Outside of Strasburg, the starter situation seems similar to the reliever situation — an overall wash, with the normal exception for shiny ERAs tend to rise. Starsburg’s ERA, FIP and FRA will be interesting to watch. Which metric will drift? Will his FRA come down or will his ERA and even his FIP take a leap? People tell me I’m a numbers guy, so I won’t admit I have faith in Strasburg’s stuff to over achieve against some metrics. Wait, did I say that out loud?

Note: All numbers through Wednesday’s games.

Harry Pavlidis is the founder of Pitch Info. Follow him on Twitter: @harrypav.