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A Resurgent Zack Greinke Leading Arizona To NL West Title Showdown

Joe Camporeale- USA TODAY Sports

Arizona’s ace has the Diamondbacks locked and loaded for a three-team showdown for the NL West title.

Over the course of the first two months of the season, the Arizona Diamondbacks have been one of the league’s most improved teams. The most surprising aspect to the Diamondbacks’s resurgence has been the improvement of ace Zack Greinke. The Arizona Diamondbacks gave Zack Greinke the highest annual contract for a pitcher in MLB history with the expectation that he would front a starting rotation to propel the Diamondbacks into playoff contention.

In Greinke’s first season with Arizona, he did not meet this expectation. Unfortunately for the Diamondbacks, his struggles in 2016 were well-documented. However, in 2017, the Diamondbacks are finally getting the results they expected after last year’s disappointing results. In 2016, Greinke pitched to a 13-7 record with a 4.37 ERA and a 4.12 FIP. This year, Greinke has returned to form, pitching to a 8-3 record with a 3.20 ERA and a 3.17 FIP. Across the board, Greinke has posted better numbers:

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So what has led Greinke back to ace status? A look into Greinke’s heatmaps in 2016 and 2017 reveal what caused him to struggle in 2016 and surge in 2017. In 2016, a huge problem for Greinke was the location of his fastball:

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As the chart shows, Greinke was hammered by right-handed batters when he tried to attack them up-and-in. When Greinke pitched inside and up in the zone, the value of his fastball decreased dramatically compared to the other parts of the strike zone. This suggests that Greinke had more location troubles with his fastball. However, in 2017, Greinke’s heatmap tells a different story that suggests Greinke made adjustments to his fastball:

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This is a huge difference from his 2016 heatmap. Overall, Greinke’s fastball has been more valuable at almost all parts of the strikezone.  Greinke is no longer getting burned on the up-and-in fastball to right-handed hitters. Instead, his fastball up-and-in has been a successful location for Greinke  and he is doing this despite losing one mile on it

Usually, when a pitcher begins to lose a little velocity on their fastball, they tend to find success attacking the corners of the strike zone and throwing more strikes. However, Greinke’s case is unusual because he is throwing less strikes than he did the previous year. Of the 102 qualified starters, Greinke is only above three other starter pitchers with a 39% zone percentage.  

Greinke has also benefited from his slider. Although he uses it sparingly, his slider is a major reason why Greinke’s K rate has increased and why hitters are getting fooled, resulting in them swinging at pitches out of the strike zone:

Greinke has always been known to have an effective slider, holding opponents to a mere .154 batting average over the course of his career with the pitch. However, the reason his slider has been so valuable this year compared to last year is that hitters are not making contact with the pitch as much in 2017:

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As the chart shows, Greinke’s Z-Contact percent for his slider is significantly lower. In 2016, his slider had a high contact rate at 91%. This year, Greinke has been able to use his slider to get opposing hitters to chase pitches out of the zone. His O-Swing percent has increased from 48% to 55%, which means that hitters are swinging at Greinke’s slider out of the zone more than last year. 

As of June 12th, the Diamondbacks hold a 39-26 record, good for a playoff spot but only for third in a highly competitive NL West, and two games behind the Colorado Rockies for first place. Last year, they were 27-37 at this point. At the pace the Diamondbacks are going, they are on target to win 97 games this year. For a team that has not played postseason baseball since their last division title in 2011, this is a good sign. Thanks to Greinke, the team’s pitching staff is a strength this year: they are second in ERA, fifth in quality starts, and fourth in both BAA and WHIP.  

Due to the strong start to the season, the expectation is that Greinke can finish the season with statistical numbers that rival his 2014 All-Star numbers with the Dodgers. What Greinke needs to count on, however, is that hitters will begin to make adjustments to his slider and lay off the breaking pitch out of the zone more. If this does happen, Greinke would need to counter with his fastball and change the delivery of his slider.  

It is clear that Zack Greinke, after a disappointing 2016, has come back to being the frontline ace that the Diamondbacks were hoping for. Although some may say Greinke’s new personal catcher Jeff Mathis deserves some of the credit, Greinke is fooling hitters better than ever with a rejuvenated fastball and a slider that is better than ever. And that is something Mathis cannot get credit for. 

**(All data has been retrieved from,, and ESPN)

Edited by Joe Sparacio, Emily Greitzer.

When did Zack Greinke win the Cy Young Award?
Created 6/13/17
  1. 2009
  2. 2015
  3. 2012
  4. 2014

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