Matt Boyd's curveball is both amazing and terrible

First drafted in 2012 in the 13th round by the Cincinnati Reds, Matt Boyd made his major league debut over the weekend. It was not, however,  with the Reds, since Boyd did not sign in 2012. He was taken in the 6th round by the Toronto Blue Jays in 2013. According to Baseball America, Boyd's highest prospect ranking was 29th within the Blue Jays organization after the 2014 season. Kiley McDaniel did not feature him in his top 200 prospects prior to this season. All this to say that Boyd was not a heralded prospect.

Perhaps contrary to his prospect status, Boyd did not stay at any level very long. He was in A ball as recently as 2013, the year he was drafted, he spent time across two levels in both 2013 and 2014, but he started 2015 in AA. He made only two starts in AAA before receiving a callup from the Blue Jays to help their struggling/injurious starting rotation.

Boyd earned the callup, more or less. In his 73.2 AA innings in 2015, he sported a 25.6 percent strikeout rate and 6.6 percent walk rate for a 19 percentage point differential between the two, which ranked among the best in AA. In fact, this is something of a character trait of Boyd's. He's run a high strikeout rate and low walk rate throughout his minor league career. It's the batting average on balls in play, left on base rate, and home runs that have fluctuated wildly. All this to say that not heralding Boyd as a prospect missed the mark perhaps.

However, there is no mention of his actual stuff here. From Baseball Prospectus for a mention of his actual stuff:

A southpaw capable of touching 92, Boyd throws four pitches for strikes. He probably won’t be a big bat-misser at the highest level—only his slider has a fighting chance to grade better than average—but he can work both sides of the plate and has just enough stuff to be tough on righties as well as lefties. The door isn’t closed on a future in the back of a big-league rotation, but if the Jays are looking for left-handed help in the bullpen, he could be ready for the role this summer. Encouragingly, he’s struck out 24 hitters in his first three Double-A starts after struggling to adjust to the level in 2014.

There is no mention of his curveball, and the "rosy projection" was a back-end starter. As you have likely gleaned from the title, Matt Boyd does throw a curveball. In fact, he threw it five times according to both PitchF/X and Brooks Baseball. The best of it and the worst of it showed in his debut. If he can harness the pitch, I'd say the rosy projection is well within reach.

The Amazing

I'll refer you to visual evidence. This bender gem was thrown to Joey Gallo in the top of the 4th inning on a 1-2 count. Boyd basically nailed his target and froze Gallo solid.

Watch Matt Boyd stun Joey Gallo with this big hook for the backwards K (Thanks to @tejasxb for the request!) pic.twitter.com/ZmhYvYCrye

— Pitcher List (@ThePitcherList) June 27, 2015

This pitch had 7.95 inches of horizontal break and 7.43 inches of vertical drop while thrown at 74.8 mph and located in zone 11 (Baseball Savant zone definition). I decided to examine pitches like it in Baseball Savant to see what happens with similar pitches. So I looked up all curveballs thrown in 2015 by lefties between 74 and 76 mph. What I found is that this is a rare pitch, thrown only 51 times in 2015. I expanded the search to include 2014 and got 195 results. In terms of movement, velocity, and location, pitches thrown by Gio Gonzalez, Hyun-Jin Ryu, and Jeremy Affeldt appear to be close matches. That's not really worthwhile analysis other than to say that's a rare place to throw a curveball like that, so I just decided to compare Boyd's curveball against all curveballs in that velocity range in that zone.

Obviously, since the pitch is located outside the zone, most are balls -- 58.5 percent. However, 22.1 percent of the pitches are called strikes. Boyd got the called strike; not only did Boyd throw a rare pitch (by movement) to a rare location, he got the rarer call. Dioner Navarro was the catcher there, but he is not a well-regarded framer (by StatCorner's estimation). It looked like he did a pretty good job of framing that pitch; the in-game zone locator had the pitch outside the zone as well. Perhaps Boyd got away with this pitch, but it looked pretty darn good. I would be eating dirt if I were standing in the box.

The Terrible

The visual evidence follows. In the top of the fifth, the very next inning, Boyd faced Robinson Chirinos. On a 1-2 count, Boyd decided to unleash the curveball again.

That thing just hung. And hung. And then was hung over the fence in left field. Compared to his earlier curveball, with which Joey Gallo could do nothing, this curveball had less horizontal movement, less vertical movement, and caught more of the plate against a hitter of the opposite hand. A recipe for disaster, if you ask me. Then again, comparing to similar pitches to get an idea of what normally happens with this type of pitch would be a good thing.

Using similar parameters as before (velocity between 70 and 72 mph), I gathered curveballs thrown in that location by left-handed pitchers in 2014 and 2015. There weren't that many (only 39), but John Danks had the most (that is not illustrious company), however, 27 of the 39 pitches were called strikes. In fact, looking at the nearest neighbors separately by horizontal movement and vertical movement, most of the "comparable" pitches were called strikes. Restricting the sample to only right-handed hitters, most of the pitches were still called strikes.

You know what? It kind of seems like the curveball I've labeled as "Terrible" was terrible based giving up a home run where a called strike was the most common result. Similarly, the curveball I've labeled as "Amazing" was amazing based on getting a called strike where a ball was the most common result. Results aren't everything, and Boyd will need to take that to heart as he journeys through major league baseball.

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Kevin Ruprecht is the Managing Editor of Beyond the Box Score. He also writes for Royals Review. You can follow him on Twitter at @KevinRuprecht.