24 February 2015

Examining De Aza's Struggles Against Southpaws

Alejandro De Aza has been a major league regular for three full seasons, though his best offensive work came in limited duty in 2011 when he posted a 150 wRC+ in 171 plate appearances. In the three years since, he hasn't come close to approaching that stat line, and his numbers have actually been trending downward:

2012: 585 PA, 106 wRC+
2013: 675 PA, 98 wRC+
2014: 528 PA, 94 wRC+

When the Orioles acquired De Aza from the White Sox late last August for two minor league pitchers, he was struggling mightily. In 439 plate appearances, he had a slash line of just .243/.309/.354 (84 wRC+). But after the trade, he batted .293/.341/.537 (145 wRC+) in 89 plate appearances and was a useful weapon (obvious small sample size qualifier).

In 2015, Steamer projects De Aza to post a 101 wRC+, which is right in line with what the average major league corner outfielder posted in 2014. But that would also reverse De Aza's downward trend of overall offensive performance over the last few seasons.

De Aza has clearly been better throughout his career against right-handed pitching:

vs. RHP: 103 wRC+ (1,717 PA)
vs. LHP: 85 wRC+ (459 PA)

Somehow, he managed to perform better against left-handed pitching than right-handed pitching in 2013 (123 wRC+ vs. 90 wRC+). A .355 BABIP against lefties elevated those numbers. But in 2014, he was truly awful against lefties:

vs. RHP: 113 wRC+ (433 PA)
vs. LHP: 9 wRC+ (95 PA)

That's right: 9 wRC+. So what happened? For one, lefties started to attack De Aza even more on the outside corner of the plate. Here's where De Aza saw pitches from lefties in the 2012 and 2013 seasons combined:

And here's where he saw pitches from lefties in 2014:

De Aza saw fewer pitches in the middle of the plate and more low and away. His whiff rate jumped:

After his improved 2013 against lefties, opposing southpaws went back to throwing De Aza more breaking pitches in 2014 with two strikes:


Overall, his strikeout percentage went from 18.6% in 2012 to 22.5% in 2014. He also chased more pitches outside the strike zone (32.1%; career 28.8%) while making less overall contact (78.2% vs. career 79.9%). That coincided with a drop of his average on balls in play from .339 in 2012 to .317 last season (career BABIP of .330), which has been partially affected by De Aza's infield fly ball percentage rising from 6.2% in 2012 to 10% last season. His HR/FB rate also dropped back to his career average (7.9%) after hovering around 11% in 2013.

The most obvious way to get around De Aza's struggles against left-handed pitching is to stop using him as much against them. Here's his plate appearance totals against lefties since 2012 (with percentage of all plate appearances against lefties):

2012: 147 PA (25%)
2013: 153 PA (23%)
2014: 95 PA (18%)

At the time he was traded to the Orioles, De Aza had faced right-handed pitching 357 times and lefties 82 times. So he faced lefties about 19% of the time. After the trade, De Aza faced right-handers 76 times and left-handers 13 times (so about 15% of the time). That's not a huge change, and maybe it wasn't necessarily done by design. But it makes sense to limit De Aza's at-bats against lefties, and Buck Showalter is adept at utilizing platoon options.

Steve Pearce is the obvious right-handed batter to slide into a corner outfield spot when a lefty is on the mound. But what about the other spot? Travis Snider and David Lough are both lefties and aren't great options to face southpaws either. Perhaps Delmon Young (shudder) could receive some playing time in the outfield when a lefty is on the mound. Regardless, though, fitting all of De Aza, Snider, Pearce, Lough, and Young on the roster may present some challenges.

Perhaps De Aza is due for an uptick in BABIP. Maybe he'll also enjoy the shorter porch in right field at Camden Yards over a full season. De Aza certainly isn't as bad against left-handed pitching as he was in 2014, but he still doesn't fare well against them; they may also have figured out an even better way of handling him. Still, De Aza's numbers against right-handed pitching have mostly remained steady, and they should again in 2015. And there's definitely value in a $5 million decent-fielding corner outfielder who can hit well against right-handers.

Photo: Keith Allison


Philip said...

So it appears that the OF roster is crowded and unbalanced.
This seems to be a problem without an in-house solution.
It is unlikely that Dan Duquette wasn't aware of this imbalance when he retained De Aza and traded for Snider, so might one anticipate a trade?
If so, any trade partners come to mind?

Matt Kremnitzer said...

The Orioles think higher of Dariel Alvarez than anyone else, so he is one possible right-handed outfielder who is an in-house solution. Who knows how that will turn out. The same goes for the low-risk signing of Nolan Reimold, I guess.

Lough could be in trouble. He doesn't have any options left. But De Aza, Pearce, and Young are all free agents after this year. Snider is under team control for another season. De Aza and Lough could be trade options, or any of this group, really, but they likely wouldn't net much of a return.

Tim said...

Re: Alvarez. Orioles were also said to be high on Urrutia until they were not. Beat writers are reporters as opposed to great evaluators who note the silver tongues of front office people and managers.

Matt Kremnitzer said...

Agreed, but I'm not just going off of what beat reporters have said. Prospect writer Kiley McDaniel briefly discussed how highly the Orioles view Alvarez (http://www.fangraphs.com/blogs/evaluating-the-prospects-baltimore-orioles/). The great thing is that no one knows for sure how good he will be. Anyway, I'm done writing off prospects after what Caleb Joseph showed last year. I definitely did not see that coming. It may be unlikely that Alvarez turns into something useful, but it's possible.

Berdj Joseph Rassam said...

I don't know De Aza is an okay player; he'll never be spectacular or below average, just steady mid to hi .200 BA and low to mid .300 OB.