What's wrong with Washington Nationals reliever Aaron Barrett?

Entering play on Friday, the Washington Nationals bullpen had been outstanding in May.  They'd allowed just 23 earned runs in 73.1 innings on the month, good for a 2.82 ERA.  Of course, one weekend got to show us just how volatile relievers can be.  Nationals relievers threw 10.2 innings in the three game series in Cincinnati.  They allowed 14 runs (all earned) and took all three losses as the Nats were swept in the Queen City.  The previous 28 days of terrific bullpen work suddenly seemed to disappear, as the Nats final bullpen ERA for May ended up jumping more than a full run to 3.96.

This is the life of a reliever.  They deal in minuscule samples, so a handful of bad outings often end up overshadowing a bucketful of really strong outings.  If a reliever who usually throws just one inning has one disastrous outing (say, three runs in an inning), he'll need to throw eight scoreless appearances to bring his ERA back down to 3.00.  A guy being absolutely dominant in eight (different) games in a row is more difficult than it sounds... and it sounds pretty difficult in the first place.

Relievers don't generally throw long outings, so when they do hit a rough patch, they don't really have many opportunities to try and work through their issues in game situations.  When a starting pitcher goes out and struggles with his command in the first inning of his appearance, he usually has a bit of a leash.  We've often talked about Gio Gonzalez (6.00 ERA in the first inning in 2014) and Stephen Strasburg (4.50 ERA in the first inning in 2014) settling in as the game moves along.  They may not necessarily be sharp with their command early on.  They may be struggling with their mechanics.  After an inning or two, they often find it.

Relievers don't have that advantage.  If they come in and struggle with their command or mechanics for an inning (or a couple of batters), they're usually getting pulled in favor of the next guy.  They can try working through those issues in bullpen sessions, but that's just not the same as facing live hitters.  This can often lead to a reliever who struggles in one appearance hitting a bump in the road where they have a series of several disappointing outings in a row.

Aaron Barrett is going through one of those bumps in the road right now.  He obviously wasn't good in the Reds series, but his problems started before that.  Over his past ten outings, Barrett has allowed 8 runs on 9 hits and 3 walks.  He's thrown just 5 innings in those ten appearances.  Most of those appearances were outings where he was used as a ROOGY and removed in favor of either Matt Thornton or Matt Grace when a lefty stepped into the batter's box.  He's faced an average of just 2.6 batters per appearance throughout this stretch, including three outings where he came in just to face one batter.  It worked in two of those... the other was Kris Bryant's game-tying homer last week.

As with many relievers, the first thing we'll think about with Barrett is the most recent thing that happened to him.  Honestly, it's tough to fault his pitching for much in Sunday's game.  Barrett faced three batters....

• He got ahead of Marlon Byrd and got him to chase a slider off the plate away.  Byrd hit it off the end of his bat and hit an extremely weak grounder to the 3.5 hole.  The Nats were shading Byrd to pull and by the time Danny Espinosa got to it, he had no shot... It was a weak infield BABIP single
• Barrett threw nothing but strikes to Billy Hamilton, actually throwing four of them (the ump missed the lone ball at the top of the zone) and got Hamilton to pop up a bunt right back to him.  Barrett misplayed it, let it drop, and threw out Byrd at second base.  This is a tradeoff that the Reds had to love
• Barrett actually kept Hamilton fairly close and had a quick move to the plate when Hamilton finally went.  Hamilton just beat the Nats with the stolen base
• Barrett did actually make a pretty good 3-1 pitch to Brandon Phillips and got a grounder towards the 5.5 hole.  Ian Desmond froze a bit before moving to his right and it just got under his glove and into left field

That was Aaron Barrett's outing yesterday.  The final line reads two hits and two runs in 0.1 innings.  He gave up a nubber off the end of the bat that ended up being perfectly placed for an infield single and another single that Desmond probably gets to if he'd gotten a better read on the ball when Phillips hit it.

I brought up BABIP... Why did I bring up BABIP?  Barrett's BABIP for the month of May (when he had a 10.29 ERA and 1.86 WHIP) was .450! His peripherals weren't great in May (4.09 FIP), but he did have 11.57 K/9.  He had a 9:3 strikeout to walk ratio in 7 innings.  His batted ball profile doesn't suggest that his BABIP should have gone crazy.  He actually had a lower line drive rate (30.0% vs. 36.4%) and lower ground ball rate (25.0% vs. 40.9%) than he did in April, when his BABIP was .318... yes, that's higher than league average, too.  This poor luck had been going on for the better part of a month, and it came to a head on Sunday when an infield single, a (OK.. his own) dropped popup, and a single to left field that probably should have been kept on the infield cost him and the Nats a game.

There's nothing wrong with Aaron Barrett.  Maybe it would be best for Matt Williams to let him throw a full inning in a lower leverage spot in the next couple of days if that opportunity presents itself.  This might help him regain some confidence.  Barrett's maintaining the high strikeout rate.  He's actually improved his control a bit from last season.  He's just getting BABIPed to death.  His BABIP allowed is liable to regress to the mean as long as he keeps doing what he's been doing.