by Steve Mancuso

Strong, early returns from Sonny Gray

In January, the Reds acquired Sonny Gray from the New York Yankees for second base prospect Shed Long and the Reds’ 2019 Competitive Balance Round A pick. The Reds also received minor league pitcher Reiver Sanmartin.

During a formal 72-hour window, the Reds and Gray reached agreement on a 3-year, $30.5 million contract extension covering 2020-22. Gray was already due $7.5 million for 2019 under his final season before free agency. The extension covers Gray’s age 30-32 seasons. The Reds also have a $12 million option for 2023.

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The Yankees had acquired Sonny Gray from the Oakland Athletics in a July 2017 trade for three prospects. Oakland had selected Gray in the 1st round (18th overall) of the 2011 MLB draft out of Vanderbilt. Gray debuted for the A’s in 2013, making 10 starts. Gray pitched well for much of his time with the A’s, finishing third in AL Cy Young voting in 2015.

Sonny Gray’s time in pinstripes, however, was controversial. Gray made 34 starts and 7 appearances as a reliever for the Yankees. Fans dwelled on his 15-16 Win-Loss record and 4.51 ERA. Gray had been really bad at Yankee Stadium, with a not-so-crowd-pleasing 6.98 ERA in 15 home games in 2018. The Yankees left Gray off the post-season roster for the AL Wild Card Game and Division Series.

Despite a team-friendly contract for 2019 and uncertainty due to injuries in the starting rotation, the Yankees were eager to move Gray in the offseason. The level of dissatisfaction among Yankee fans was so high the club announced shortly after the 2018 season it would be “open-minded to a relocation” for Gray. The trade with the Reds followed a few months later.

The hope in Cincinnati was that Sonny Gray had been a poor fit for the spotlight of Gotham. Gray seemed like an ideal “change of scenery” candidate, particularly because of the pending reunion with his college pitching coach, Derek Johnson, whom the Reds had just lured away from the Milwaukee Brewers.

But many Reds fans looked at Gray’s ERA with the Yankees and thought the price of that draft pick and Shed Long was too high for a pitcher who would need a “rebound” season to make the trade worthwhile.

Skepticism was commonplace.

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Pitch movement is the amount the ball’s trajectory deviates from a straight line, subtracting the effect of gravity. Movement can be up or down (vertical) or to the side (horizontal).

Why do pitchers try to generate movement?

Because pitch movement disrupts the hitter. It throws off anticipation and timing.

What affects pitch movement? One large factor is the spin of the ball. As a baseball travels toward home plate, its seams push the air around it. That’s called the Magnus force and it causes the ball to change direction. The ball’s rate of spin determines how strong the Magnus effect is for each pitch.

But not all spin is the same. There are two types.

One kind of spin – gyrospin – is what a bullet has when fired from a gun. Gyrospin prevents the object from moving along its trajectory. The second type of spin – transverse – is what makes the ball move.

A good way to understand the difference is to think of a football quarterback and a baseball pitcher. Both of them throw balls and value accuracy. But a quarterback wants to minimize the ball’s movement on its trajectory. So he learns how to throw a spiral, dominated by gyrospin. A baseball pitcher, in contrast, is trying to throw off the hitter. He wants to throw with transverse spin to get movement along trajectory.

Of course we have a way to measure on a given pitch how much is transverse spin and how much is gyrospin.

“Spin efficiency” measures transverse spin in relation to gyrospin. The more “good” spin a pitch has, the higher the efficiency. Spin efficiency is an important way to evaluate pitchers.

The good news for pitchers (and their coaches) is that pitchers control the ball’s spin. That means they influence pitch movement. Pitchers do that by how they grip the ball, the amount of pressure they apply, and their release angle. The tilt (or axis) and release point also affect ball movement.

If all this stuff about spin and spin efficiency sounds fundamental to good pitching, well it is. But until the past few years, it was beyond precise measurement. The advent of pitch-tracking technology has turned mastering movement from art to science.

High-speed cameras and radar give pitchers information on velocity, location and movement. A pitcher can experiment with a new grip and get immediate, precise feedback. Will tucking his thumb a little bit create more sidespin and movement?

Pitchers can give it a try and find out, in real time.

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The Reds had scouted, measured and analyzed Sonny Gray’s spin efficiency before they made the trade.

Dick Williams and the Reds analytics department decided that Gray still had the underlying physical skills to be an effective pitcher. Further, Gray had always exhibited a high ground ball rate, a desirable quality in any ballpark, but particularly valuable at homer-prone Great American.

After the deal was finalized, Gray threw in front of Johnson in Nashville, where they both live in the offseason. Using modern tracking devices to analyze his pitches, Gray found that while he had a high spin rate on his fastball, it was mostly gyrospin. He worked hard in the offseason to get his spin efficiency higher.

Caleb Cotham, who had pitched for both the Yankees and briefly with the Reds (courtesy of the Aroldis Chapman trade), had been working for a high-tech pitching instruction business. Cotham possesses a unique skill in being able to translate fancy data to players in ways they understand. He also happened to be a long-time friend to Sonny Gray. The Reds hired Cotham to be their assistant pitching coach.

Cotham worked with Gray on his slider and curveball. The Yankees had wanted Gray to throw his slider more often and as a strike. But Gray was more comfortable using it as a swing-and-miss pitch in the dirt. Cotham also encouraged Gray to throw his curveball more. The data showed it was effective.

Sonny Gray had always been known for pitch movement.

“When you talk about Sonny, you talk about movement,” said Stephen Vogt, who caught Gray with the A’s. “His fastball moves both directions, cut and sink. He has the ability to really manipulate the ball, even mid-pitch, to make it move a little bit or less than any other pitch, as well as with the slider.” (Bobby Nightengale)

Imagine that pitcher armed with new detailed data and instruction.

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Gray’s time with the Reds didn’t get off to a great start. He began spring training with elbow discomfort that set back his preparation. But by the time his turn in the starting rotation came in the regular season, Gray was ready. He took the mound at Great American Ball Park on March 31, the Reds second game of the season, and hasn’t missed a start since.

The results of his work with Cotham and Johnson have been dramatic.


Gray slider’s spin rate is up from 2710 rpm to 2759 rpm. He has added several inches to its horizontal movement (7.4 inches to 10.3 inches). Gray’s slider ranks fourth out of 308 pitchers in horizontal break and 16 out of 308 in vertical movement.

The chart plots slider movement for pitchers, with horizontal movement on the x-axis and vertical movement on the y-axis. The red arrow is pointing at the Sonny Gray dot. It’s way out in the quadrant with the most vertical and horizontal break.

Instead of using his slider for strikes to get ahead in the count, Gray has been using his slider primarily in 1-2 and 2-2 counts to finish off hitters.

This chart shows Gray’s pitch usage based on count. Gray relies on his 4-seam fastball (red), his sinker/cutter (orange) and curveball (blue) to throw strikes. He seldom uses his slider (yellow) when he’s even or behind in the count. It becomes a dominant pitch when he’s ahead.

Sonny Gray has thrown 195 sliders this season. He’s generated a ground ball rate of 62.50% on balls put in play. Batting average against his slider is just .100 and isolated power against is .000. On 24 balls put in play, 5 have gone for singles. Gray hasn’t given up an extra-base hit on his slider.


Gray has had similar success with his curveball. It breaks 7.2 inches horizontal and 3 inches vertical. His curveball spin rate of 2910 rpm is in the 96th percentile. Here’s a similar chart to the one above, only for curveballs instead of sliders.

Gray (red arrow) again is an outlier in the best quadrant.

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The narrative that Sonny Gray needed a bounce-back season with the Reds to make the trade worthwhile was never accurate.

Gray’s ERA with the Yankees (4.90) was inflated compared to his career number (3.67). But when you strip out luck and defense, Gray’s numbers looked closer to normal. His FIP (4.17) wasn’t far off his career (3.71) and the same with his xFIP (4.10 vs. 3.69). Both of those numbers from 2018 were better than league average.

Gray’s walk-rate was a bit higher with the Yankees, but his strikeout rate had remained consistent. His fastball velocity had remained steady. ERA is the worst measure of all of those, for a variety of reasons.

So Gray really didn’t need to show huge improvement.

Yet he has.

Sonny Gray’s strikeout rate (26.7%) and ground ball rate (55.9%) are the highest of his career and both well above league average for starting pitchers. Gray’s fastball velocity (93.9 mph) is right at his career level.

Gray’s ERA of 3.77 is 15% below league average ERA of 4.45. Keep in mind that includes two “earned” runs that scored on a misfielded popup that landed in front of first base.

His FIP (3.22) and xFIP (3.46) are 20%+ lower than league average. He leads Reds starting pitchers in those two measures.

In terms of “expected” stats – based on the quality of contact he’s allowed – Gray is in the 78th percentile for Batting Average, 82nd percentile for Slugging, and 80th percentile for Weighted On-Base Average.

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In agreeing to a 3-year extension, the Reds made a medium-to-large sized investment in Sonny Gray.

Early returns are promising.

The turnaround overall in Reds pitching has been remarkable. Just a couple years ago, the Reds staff had been described as one of the worst of all time. Now, it is one of the best in the major leagues. Sonny Gray has been an important part of that.

[Charts and data courtesy of FanGraphs, Baseball Savant and Brooks Baseball]

Steve Mancuso is a lifelong Reds fan who grew up during the Big Red Machine era. He’s been writing about the Reds for more than ten years. Steve’s fondest memories about the Reds include attending a couple 1975 World Series games, being at Homer Bailey’s second no-hitter and going nuts for Jay Bruce at Clinchmas. Steve was also at all three games of the 2012 NLDS, but it’s too soon to talk about that.