FanPost

Aaron Altherr is Waiting for His Pitch

For a quarter of a season last year, Aaron Altherr played at an All-Star level. Yet coming into the 2016 season, nobody is confident enough to include him in that group of players we like to call the future "core" of the team. The hesitation is understandable, as we have become accustomed to shrugging off small sample sizes. But there might be more to his debut than a fortunately timed hot streak. A month before his call-up to the Phillies, Altherr had this to say about his most recent success in the minor leagues:

"I’m trying not to swing at pitches that I haven’t been looking for. It’s been [focus] in on one zone and don’t look at anything else. I’m getting better at that and I still have to get better, but I’m making good progress."

We hear statements like this from players all the time, and we usually brush them off because we don't often see follow through in the batter's box. But in Altherr's case, these are more than just empty words, and there are numbers to back up this stated patient approach. These are Altherr’s swing rates versus the league average in 2015.

O-Swing%

Z-Swing%

Swing%

Aaron Altherr

24.4%

63.2%

41.6%

League Average

31.3%

66.9%

47.4%


Swing rate can tell you a lot about a player's approach at the plate. It's also the quickest stat to stabilize, at less than 50 plate appearances, which means we can't dismiss Altherr's low swing rate numbers on account of the sample size. Let's look at these numbers in turn and see what they’re telling us.

Altherr's ability to avoid swinging at pitches outside of the strike zone (O-Swing%) is directly reflected in his walk rate, which was an impressive 9.9% last year. But the benefit of laying off bad pitches doesn't end with just a few extra walks. Across the league, BABIP also runs much higher on contact inside the strike zone versus out. This is an unsurprising outcome, but it's always nice to see how the numbers back up intuition.

Season

Out of Zone BABIP

In Zone BABIP

2008

.264

.307

2009

.270

.306

2010

.263

.301

2011

.268

.300

2012

.267

.301

2013

.271

.299

Total

.267

.302


Altherr's plate discipline goes beyond just discerning balls and strikes, though, as he also runs a low swing rate on pitches inside the strike zone (Z-Swing%). This is a result of pitch selectivity. Altherr is not swinging at just anything inside the strike zone, but instead waiting on HIS pitch to hit. Here are three charts showing this concept in action.

This first chart shows the location of pitches where Altherr has done the most damage, by SLG%. Like a lot of hitters, he is most effective hitting pitches middle-in, but he also handles pitches well in the upper half of the strike zone.

This second chart shows how opposing pitchers have pitched to Altherr, showing the percentage of pitches thrown to each area of the zone. Pitchers are mostly throwing to the outer half of the strike zone against Altherr, especially down and away, where hitters in general are less effective.

Tying it together is this third chart, which is Altherr's swing rate in the different areas of the zone. If you overlap all three charts, you'll notice that his swing percentage is highest on pitches where his SLG% is also highest, despite those pitches being fewer in total number. Altherr is not swinging at strikes on the outer half of the plate, where his contact quality is weakest, instead focusing on the inner half where he can drive pitches with better success. This approach has paid dividends for Altherr in 2015, where he’s run career bests in ISO and BB% across three levels of baseball.

The downside of this patient approach is that it results in Altherr finding himself in more two strike counts. That's why, despite an average contact rate, his strikeout numbers will run slightly higher than a more aggressive hitter with similar contact ability. But if the end result is trading a few extra strikeouts for more quality contact, it's a worthwhile trade off.

Maintaining this approach will be key to Altherr's success going forward, as focusing on those high percentage pitches will let him get to the above average power in his long frame. He’s unlikely to hit for a high batting average, but walks and extra base hits will be a big part of his game. Altherr's speed and exceptional defense already give him a valuable floor as a major league regular. The plate discipline might give him the ceiling of an All-Star.