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Statcast Week 6: Sonny Days Ahead

Miami Marlins v Oakland Athletics
Sonny’s stuff reemerged in his best start of the season against Miami. Will is stick around?
Photo by Lachlan Cunningham/Getty Images

Oakland A’s ace Sonny Gray is making headlines again! And another one, here. It appears his trade value is returning to normal levels — have his skills returned, too?

Sonny currently sports the lowest walk rate of his career (6.7%) and the second best strikeout rate of his career (23.3%) aided by a career-best 11.2 swinging-strike percentage. It appears his batted ball data is right in line with his career norm. One concern is that his HR/9 is still well above 1, and has increased nearly each season he’s been a major leaguer.

He’s getting plenty of strikeouts and doing a fine job of limiting walks. As long as not too many many men are on base the occasional long ball won’t kill him. Two questions remain: Is what Gray is doing legitimate and is it sustainable? Statcast might have the answer for us.

xStats, provided by Statcast, offer some insight into whether or not Gray’s results thus far have been earned, and what they look like compared to previous seasons.

Sonny Gray’s xStats

Year Pitches BA ISO BABIP SLG wOBA xwOBA xBA Exit Velocity Launch Angle
Year Pitches BA ISO BABIP SLG wOBA xwOBA xBA Exit Velocity Launch Angle
2012-2015 7368 0.223 0.095 0.270 0.319 0.271 0.156 0.099 87.4 8.4
2016 1947 0.286 0.189 0.319 0.475 0.352 0.332 0.266 85.9 9.2
2017 483 0.216 0.144 0.250 0.360 0.275 0.287 0.222 87.1 2.2

It seems like Gray’s 2017 results are similar to his pre-2016 numbers, which is definitely a good thing. Oddly Gray allowed a lower average exit-velocity in 2016 when he was not a good pitcher. So what is making Gray successful? In 2016 Gray got killed when he left pitches around the heart of the plate. This season he’s doing much better in limiting hard contact on pitches in the middle of the zone.


Sonny Gray 2016 Pitch Chart


Sonny Gray 2017 Pitch Chart

Statcast by Pitch

In 2016 Gray’s fastball was simply terrible. This year his fastball has seen far better results.

Sonny Gray’s Fastball

Year BA ISO BABIP SLG wOBA xwOBA xBA Exit Velocity Launch Angle Spin Rate Velocity
Year BA ISO BABIP SLG wOBA xwOBA xBA Exit Velocity Launch Angle Spin Rate Velocity
2016 0.321 0.191 0.329 0.512 0.392 0.373 0.295 90.1 4.1 2397 93.4
2017 0.238 0.111 0.264 0.349 0.289 0.286 0.225 88.4 -2.2 2488 93.7

Gray’s fastball has improved in 2017 across the board including, and especially in spin rate. Spin rate is interesting and a new statistic in the world of baseball. “Why does spin rate matter” and “what does it mean” are two very important questions to consider when using it to justify a player’s breakout or resurgence.

Per Statcast:

The amount of spin on a pitch changes its trajectory. The same pitch thrown at the same Velocity will end up in a different place depending on how much it spins. (For instance, a fastball with a high Spin Rate appears to have a rising effect on the hitter, and it crosses the plate a few inches higher than a fastball of equal Velocity with a lower Spin Rate. Conversely, a lower Spin Rate on a changeup tends to create more movement.)

As more data have become available, most experts have agreed that fastballs and breaking balls are tougher to hit when they possess higher Spin Rates. In fact, some data suggest that Spin Rate correlates more closely than Velocity to swinging-strike percentage.

It might be safe to glean from both the data and description of spin rate that increased spin on Gray’s fastball has helped lead to more strikeouts this season. But what about his bendy stuff? Gray’s fastball has usually been good, but his curveball and slider have been excellent pitches.

Sonny Gray’s Off-speed Pitches

Year BA ISO BABIP SLG wOBA xwOBA xBA Exit Velovity Launch Angle Spin Rate
Year BA ISO BABIP SLG wOBA xwOBA xBA Exit Velovity Launch Angle Spin Rate
2016 0.182 0.212 0.254 0.394 0.249 0.235 0.19 87.2 13.7 2786
2017 0.147 0.088 0.25 0.235 0.165 0.197 0.172 86.6 16.7 2862

Gray’s curveball and slider weren’t as terrible in 2016 as his fastball was, however they’ve still been better than they were last year. Interestingly he’s put more spin on his breaking balls in 2017 than 2016.

I’m sure all of us have enjoyed seeing Sonny Gray pitch like his old self. It’s good for both Gray and the A’s organization. The team hasn’t been winning too many games, however so I expect we’ll see many trade rumors swirl in the coming weeks. If Gray can continue to prove that he’s fully back then the haul the A’s will get might push the organization closer to sustain success.