First, the big picture. The Scats are, through Saturday, 6-17, 5.5 wins below .500. Wins, however, are made up of runs, and lots of research shows that overall runs scored and runs allowed give you a more accurate picture of a team's overall repeatable skill level than W-L record.
NL-wide there have been 1706 runs scored this year. That's 107 runs scored per team. So the perfectly average .500 team would be at 107 runs scored and 107 runs allowed for an 11.5-11.5 record through 23 games. The Nationals have scored 102 runs and allowed 131, meaning they are 5 runs behind the pace on offense and 24 runs behind in run prevention (pitching plus fielding), a total of 29 runs below average overall.
In the current run-scoring environment, about every 10.1 runs (net scored and prevented) results in an additional win, so the Nationals' 29 runs below average should put them at about 2.9 games below .500, not 5.5 (that'd be an 8.6-14.4 W-L record, if you please).
That of course is what Baseball-Reference is telling us on the Nationals' team page where they say that their Pythagorean record is 9-14. That still would be the worst record in the NL, but the point is that based on runs scored and allowed the Nationals' record should be about 2-3 wins better than it is; the difference can be chalked up to poor situational performance and/or randomness.
OK, so if about 2 or 3 of our losses are due to the ill-will of the baseball gods, that means about 3 more losses are due to those 29 runs. Let's see if we can figure out where those 29 runs are being lost.
My approach here is to look at context-neutral stats that measure overall team run production and prevention in fielding, pitching, and run-scoring (including hitting, base-running, and other fundamentals of offensive execution). Combined, these three parts of the game account for pretty much everything that goes into scoring runs and ultimately winning games.
First let's look at the fielding, which is pretty simple, thanks to Ultimate Zone Rating. UZR tells us that the Nationals, through Friday's action, were 5.7 runs allowed below average in the field, ranking them 23rd of 30 teams in MLB. UZR breaks down defensive contributions to range, errors, throws, and double plays turned. The Nationals as a team are 3.6 runs below average in range, 4.0 runs below average in errors (only St. Louis is worse at -4.1), while they've made up 1.2 runs with throws and 0.6 runs with double plays. You can scroll through all the individual defensive numbers here, and you won't be surprised to learn that Ryan Zimmerman is really good at third and Adam Dunn is pretty bad in left.
Next let's look at pitching. Since we're accounting for luck and fielding elsewhere, we can isolate the pitching contribution in fielding independent ERA (FIP). The Nationals have a team FIP of 5.40, 15th out of 16 teams in the NL and 0.90 runs worse than the NL average of 4.50. The starters and relievers have both been pretty awful, but the relievers' FIP is a bit worse. The starters are at 5.36, 15th out of 16 in the NL and 0.87 runs behind the NL starting pitching average of 4.49. Meanwhile, the relievers are at 5.48 FIP, dead last in the NL and 1.05 runs behind the NL reliever average of 4.53.
Before you go assigning more blame to the bullpen than the starters though, consider that the Nationals' relievers have thrown 76.2 innings, while the average NL bullpen has thrown 73.1. The average starting rotation has thrown 134, while the Nationals have thrown 124.6. (Note that the Nationals have only played 23 games, while a set of other teams have played 24, so we're going to have to tolerate some rounding errors here.) That might not sound like much, but presumably it's your worst starting pitchers being asked to throw 10 fewer innings, while it's your worst reliever being asked to throw 3 more, so it makes a difference.
Given all that, I think it makes sense to just lump all the pitching together. In 201.1 innings, the Nationals' 0.90 runs below average FIP has cost the team a bit over 20 runs.
(Now I know what you're thinking. "There's no freaking way that the bullpen has been no worse than the starting pitching. I've watched the games." And you're right, but it's all in the situational stats. The bullpen has a dreadful 33% success rate on saves; NL average is 59%. Overall, the hitting line against our pitchers is .273 / .356 / .472. In "late and close" situations, that balloons to .281 / .416 / .508, and pretty much 100% of that you can hang on the relievers. In other words, we can assume pretty safely that a lot if not all of the difference between our Pythagorean record and our actual record is the bullpen's crappy performance in key situations. But you knew that, because you watched the games, poor you.)
Which brings us to the offense. I could get into breaking down offense by hitting and base-running and situational execution, but let's not go there just now. The simple summary is that the Nationals are scoring 4.43 runs per game, 9th in the NL and 0.13 below the NL average of 4.56. Multiplied by 23 games, that means the Nationals are 2.6 runs below par in overall scoring.
To sum up:
- Fielding: 5.7 runs below average
- Pitching: 20.1 runs below average
- Offense: 2.6 runs below average
- Total: 28.4 runs below average