Measuring D-backs pitcher Zack Godley’s decline in 2018

The 2017 Arizona Diamondbacks rotation was among the best in Major League Baseball.

Led by all-star seasons from Zack Greinke and Robbie Ray, it was easy to overlook the contributions of Taijuan Walker, Zack Godley and Patrick Corbin, who all posted solid seasons.

After tossing 155 strong innings in 2017 as Shelby Miller’s injury replacement, Godley was someone the D-backs believed could be one of the best back-of-the-rotation starters in the game.

Godley began the 2018 season on the right foot. He had a strong spring training and dominated in his first two starts. His success quickly plummeted.

So far in 2018 Godley is posting a WHIP of 1.52, up from 1.14, and he’s allowed 10 wild pitches, the most in the National League. The constant traffic on the bases has made it difficult for him to get comfortable on the mound and find a good rhythm.

His curveball was his bread-and-butter pitch that he could throw in any count and against any hitter. Godley threw his bender 35.6 percent of the time in 2017 and has increased his usage of that pitch to 40.4 percent in 2018.

Besides his curveball, Godley also features a cutter, slider and a seldomly-used changeup. As not an overwhelmingly hard thrower, Godley has thrown off-speed pitches the vast majority of his career at just under 70 percent.

Perhaps hitters have had more success against Godley this season because they’ve seen the curveball so much that it loses some of its deception.

His velocity on all of his pitches is down from 2017, including on his curveball, which has spiked down from 83.4 mph last season to 82 mph in 2018.

The struggles in 2018 have been related to command. He’s striking out hitters at a similar rate but has issued a career-high of 4.5 walks per nine innings pitched.

The most drastic change from last season has been Godley’s road struggles. In 2017 Godley posted an impressive road ERA of 3.29. This season his ERA away from Chase Field jumps all the way up to 5.37.

The two-run jump in road ERA for Godley is surprising for a pitcher who excelled away from home last season. His command on the road has been especially poor, as he’s issued 35 walks in 57 innings of work.

Godley has maintained last season’s strikeout rate in 2018. He’s averaged 9.2 strikeouts per nine innings in 2018, which is top 10 among National League pitchers.

For those who want to point to Godley’s record, look at how unlucky he was in 2017. Last season Godley put together an 8-9 record with far superior advanced stats.

His 11 wins in 2018 are more a product of run support. Godley went 4-1 in the month of June but posted a 5.06 ERA in 26 2/3 innings pitched, while receiving an average of 4.5 runs of support in 2018.

In May, Godley went 1-3 but his ERA was slightly better at 4.80.

Godley has found success trying to make opponents chase pitches outside of the zone. As hitters are more willing to take his borderline offerings, it will be up to him to work in the strike zone more in order to have success.

As a marginal prospect, Godley contributing at the major league rotation should be viewed as a win. But for a team in a pennant chase and with a bullpen that has been grossly overused it’s hard to see silver linings.

At only 28-years-old, not all is lost on Godley by any means. There is plenty of talent and swing-and-miss stuff to work with.

Perhaps it’s mechanics? Perhaps he’s lost some confidence after prolonged struggles?

Somewhere in between last year’s success and this season’s struggles is a pitcher that can help a team win games. The D-backs hope to rediscover that form in their right-hander.