Rockies starting pitcher Jon Gray added a sinker

Jon Gray has added a new trick.

While perusing Gray's Brooks Baseball player page—mostly to feed my daydreams—I stumbled across something funny on his pitch usage chart. During spring training, we learned that Gray was working on a curveball. It was designed to complement his killer slider and work-in-progress changeup. He shelved the curveball during spring training, but it has reappeared over the course of his first few outings (with success).

I don't recall hearing anything about Jon Gray adding a sinker. That's why it was so surprising to see that Gray, according to Brooks Baseball, has been throwing a sinker (or, two-seam fastball; Brooks does not distinguish between a two-seam fastball and a sinker).

It's possible that these pitches are misclassified. For instance, a four-seam fastball with a lot of movement might be mistaken for a sinker. But Brooks Baseball is among the best at rigorously reviewing these classifications. From the site's About page:

The Pitch Classifications used by Brooks Baseball are manually reviewed by Pitch Info using several parameters of each pitch's trajectory and double-checked against several other sources, such as video evidence (e.g., pitcher grip and catcher signs) and direct communication with on-field personnel (e.g., pitching coaches, catchers, and the pitchers themselves).

It's safe to conclude that Gray has been throwing actual sinkers. Gray has not, however, been throwing it for very long. Just like his new curveball, Brooks records no instances of a sinker being thrown in his 2015 innings. And, indeed, it records zero instances of Gray throwing the sinker over his first four starts. He's only been throwing it for the past two games—the first against the Giants at AT&T Park, and the second against the Mets at Coors Field.

Not only has the sinker appeared out of nowhere, but according to Brooks, Gray threw it even more than his four-seam fastball during his last outing. The four-seam fastball has long been Gray's primary pitch.

Gray's best two outings of the season were his last two starts, with sinker in tow. He pitched seven innings in both starts. His total line: 14 innings pitched, six hits, two runs (both earned), three walks, 13 strikeouts, and no home runs given up. Batters have hit .128/.196/.170 in these games. They took place at one of the most pitcher friendly parks in the majors and the most hitter friendly. We can assume that he would have fared well at the parks in between.

In the 14⅔ innings spread across the four starts prior, Gray allowed 20 hits, 13 runs (all earned), walked 4, struck out 23 and gave up two home runs. A lot of this was due to poor luck, and the walks and strikeouts indicate that he was doing just fine below the surface. Still, another variable between these outings is that he threw a sinker in the last two but not the first four.

This could be a blip, but it also might not be. If it's not, then it means that Gray was able to seamlessly integrate a new pitch into his repertoire—apparently overnight. Even if he had been working on it in between starts, the fact that he can use it effectively in game says a lot about Gray's pitching acumen. For now, we have to wait and see what he does with it next. That's the fun part.