The Nationals lead all of baseball with a very impressive 3.03 ERA. Even with the new additions to their starting pitching staff, they weren't expecting to do this well. With the Braves chasing this run prevention behemoth, there might be cause for concern about passing them to win the division. I, however, am willing to bet they'll do worse in the coming months allowing the Braves to pass them.
There are a lot of outcomes pitchers can't control. The flukiest thing is left on base percentage. Out, Out, Triple, Walk, Walk, Out yields zero runs. Walk, Walk, Triple yields two runs and a pitching change. The order in which events happen can cause pitchers their livelihood. The Nationals have been the the league leaders in LOB% with 76.%. The median is 72.4%. I thought maybe, just maybe, cerebral pitchers could use the hitter's aggressive mentality with runners on in his favor. Greg Maddux's lifetime LOB% is 72.3% I now think LOB% is about as random a variance as you can have. Being first means there's no where to go but down. From 2010-2012, the median LOB% is 72%. The highest is the Phillies with 75.4 and the lowest is the Indians with 70.2%. That's not a terrible amount of variance (about 7% more from lowest to highest, in fact), which means it's mostly luck based (for comparison, there was a 34% difference in range of K% from lowest to highest in the same time period). With this relatively little range, it shows the Nationals are bound to come back down to earth, or closer to the almighty 72%. In the first 3 months of the season, Washington is leading in the flukiest peripheral there is. The only thing that really helps LOB% is not allowing hits in the first place.
The Nationals also lead in pitcher's Babip! You'd think great defenders would help with that, but they are mediocre according to UZR and DRS. Well, maybe they cause weak contact by getting hitters to chase pitches out of the zone and get meekly hit batted balls... except they're 3rd to last in O-Zone Contact%. If their defense isn't exactly stellar, and they're not getting weak contact from outside the strike zone, I think they've been lucky with balls in play. Not only that, but they have the 3rd lowest HR/FB%! Based on peripherals, they've been giving up less hits than they should, less home runs than they should, and lead in the fluke-driven LOB%.
They have the 2nd biggest spread of xFIP-ERA, behind only the A's (who play in a huge park which will always cause them to keep more fly balls in play). They've have good luck for the first half of the year. Edwin Jackson wasn't offered a 1 year deal because he's a perennial Cy Young contender, but he's somehow performing like one. They have four relievers with sub 2.00 ERAs. Strasburg is on a well publicized innings limit. After all that good fortune, they're only 3.5 up.
The Braves are elite according to UZR and DRS, placing 1st and 2nd currently (and that's with The Rev thrown into the fire of being a ML shortstop for 2 months). The pitcher's BABIP is only mediocre. Especially now with Simmons up the middle I am willing to bet the Braves improve on their batted ball numbers soon. The Braves' were 4th in ERA last year. With most of the same pitchers and fielders, they're 16th right now. From 2009-11, the Braves had the 3rd best HR/FB ratio (humid air generally impedes fly ball distance). In 2012, they're 23rd. That will improve. With Simmons and the best defensive outfield in baseball, this is the strongest defensive team the Braves have fielded in years. Their run prevention will improve. Mark it down.
The highest LOB%, with mediocre defense, with a very low HR/FB%, playing in a neutral park means their ERA is an illusion. Washington will end up with a great ERA by season's end, but they're playing way over their heads right now. It's in black and white. I think by August the Braves will see Washington in the rear view mirror with Washington desperately trying to salvage a wildcard.