About Last Night: finding Marco Gonzales’s cutter

While Daniel Vogelbach earned all the headlines, Marco Gonzales had himself a very nice spring training. He’s a couple years removed from Tommy John surgery now and he came to Arizona completely healthy. Jerry Dipoto has raved about the growth and progress Gonzales showed this spring. Those two factors plus the circumstances of his acquisition last year have pushed the expectations for him through the roof. That’s a lot of weight to carry into your first start of the season.

To his credit, Gonzales met those expectations head on. It may not have been the most dominant start, but it was the longest outing of his career and he managed to hold the Giants in check until the seventh inning. His final line is a little marred by that final third of an inning but it’s encouraging nonetheless: six and third innings pitched, six hits and no walks, and two strikeouts.

Heading into his start, I was looking for two things: the effectiveness of his new cutter and the velocity differential between his fastball and his changeup.

It turned out tracking the first point was much harder than expected. Gonzales threw some cutters during the game but Statcast’s pitch recognition algorithm didn’t recognize them. That’s not too surprising since the algorithm has a really hard time identifying new pitches, especially for a pitcher with such a small dataset. I dug into the raw data to see if I could parse out which pitches were actually cutters. They were lumped in with his four-seam fastballs and you can kind of see them in this velocity chart from Baseball Savant.

The chart starts off with six fastballs around 90-91, matching his sinker. But then it gets all wonky and that’s when he started mixing in his cutter. All those data points around 88 mph are actually cutters and it’s borne out even more in the pitch characteristic data. Here’s a table showing just how different these two pitches actually were.

Now that we have the raw data all sorted out, we can dig a little deeper to see just how effective this new pitch was. He generated two swinging strikes with the cutter against nine swings. Opposing batters put the pitch in play four times, with an average exit velocity of just 82.5 mph. One of those balls in play fell in for a hit—Buster Posey’s bloop single—and two them were ground outs, including Posey’s ground ball double play in the fourth. I’d say that’s a pretty good debut. The cutter gives Gonzales a nice weapon against right-handed batters. As long as he’s able to continue to locate it inside, he’ll continue to generate weak, sawed-off contact and see a few whiffs as well.

Facing a lineup full of right-handed hitters, Gonzales’s changeup was his primary weapon yesterday. Reports out of spring training had his fastball velocity up around 92-94. We didn’t see that kind of velocity from him yesterday so the velocity differential between his changeup and his fastball was right around where it was last year. I think that’s okay because the shape of the pitch was a little different. He’s always been able to get a ton of horizontal run on the pitch. Yesterday, we saw a little less horizontal movement, but the pitch had a ton more drop to it. That helped him generate five ground balls off the pitch. The whiffs were mostly there too. He got five whiffs off 14 swings, pretty much in line with his career rate.

The two home runs he allowed were pretty disappointing, but I think there were more positives to take away from this first start than negatives. Gonzales was efficient, generated a ton of contact on the ground, and showed off the new weapon in his repertoire. The fastball command will need to improve before we can really get excited about his potential upside, but the version we saw yesterday is more than sufficient to hold the fifth spot in the rotation.