After a solid debut campaign in 2015, Zack Godley all but fell off the Diamondbacks’ radar in 2016. He didn’t appear until June, and when he did, the results were far from impressive, especially in the rotation. As a starter, Godley had a 7.31 ERA over nine games, and came in only 30th when fans rated the team before the season. But by the end of the year, Godley had posted the biggest improvement in rating of any Arizona player, scoring almost 3.5 points higher and finishing the season in 6th place. That’s especially impressive, given Godley appeared only once before May 10th.
He wasn’t in the rotation mix during spring training, throwing only 7.2 innings as a reliever. Opponents batted .394 against him, so it was no surprise when Zack was optioned to the Reno Aces on March 25. When we needed a replacement for Shelby Miller, Godley was first up on the bus from Reno. That was just a spot-start, but when Braden Shipley walked six in four innings for his 2017 debut, Godley returned - and this time it stuck. Over his first five outings, Zack had a 1.99 ERA and held opposing batters to a line of .204/.277/.296, for a .574 OPS, as it soon became clear that this year’s model was a different one to what we had seen previously from Godley.
In mid-May, Michael took a look at Godley, and concluded, “His ability to attack the bottom of the zone has resulted in weak contact and ground ball outs against opposing lineups. However, the big issue for Godley and the biggest obstacle to sustained excellence on the mound is command and walks.” Interestingly, Zack’s MLB walk-rate didn’t change much from 2016 to 2017. It was his strikeout rate which did, improving by a third from 7.2 per nine innings to 9.6, and the key there was Godley’s amazing curveball.
Only one NL pitcher (min 100 IP) was better than Godley at getting swings and misses on pitches out of the zone. That was team-mate Robbie Ray, and the difference there was more than made up for by Godley being better at inducing those out of zone swings. That’s likely a result of him tightening up his mechanics, so that the curveball and fastball come from the same arm-slot. As Michael noted, “When Godley is going well, batters see a lot of pitches at the very bottom of the strike zone and below.” This was echoed by Ray in August: "His curveball looks like a low fastball, and it just keeps going lower. And they have to honor it because he has such a good fastball now."
This is clearly illustrated in the chart above, which shows where Zack got his K’s. They were almost all below the belt, and in particular, note the extraordinarily high number of strikeouts down and away to right-handers (the chart is shown from a catcher’s perspective). This year, Godley became a rare combination: a swing-and-miss pitcher who also generated groundballs. Sean compared Godley to our god of groundballs, Brandon Webb in June, and with good reason. Below, is a chart of the 15 pitchers in the majors who had more ground-balls than fly-balls across their balls in play. Note how Zack gets swings and misses over 30% of the time - nobody else is even at 25%.
Ground-ball specialists, and their swing/miss %
Godley has been unsung pretty much his entire life, since he didn’t start pitching until he was a junior in high-school. At the time of the trade which brought him to Arizona, Zack was described by Leith Kaw as a “fringe prospect”. John Sickels was not much more optimistic, saying Godley “could wind up being a decent early innings reliever or mop up man in the big leagues,” and Shaun Kernahan of Baseball Essential said he “would be surprised if Godley turns into much more than a periodic big league guy.” Yet, little more than two and a half years later, Jay could legitimately write on this site, “It is Now ‘The Godley Trade’, Not ‘The Montero Trade’.”