Justin Verlander Shares Data Suggesting MLB Ball Has Changed: ‘I Don’t Like Being Lied To’

Justin Verlander has long been in the camp that believes the baseball used in the MLB has changed in recent seasons. During last year's World Series, which his Astros won, Verlander pointedly said, "[MLB commissioner] Mr. Manfred says the balls haven't changed. I think there's enough information out there to say that's not true."
Verlander shared some of that information on Thursday. The six-time All Star and 2011 American League MVP tweeted a graphic that explored the correlation between exit velocity/launch angle and home run percentage for the 2014 and 2017 seasons. While the two graphics might look pretty similar upon first glance, there's a third graphic that shows how balls that were hit at the same speed and launched at the same angle had a slightly better chance of being a home run in 2017 vs. 2014.
Been sitting on this... Exit velo and launch angle and it’s correlation to % chance of becoming a homer. 2014 vs. 2017 pic.twitter.com/UrfVVFVuJB
— Justin Verlander (@JustinVerlander) March 2, 2018
Assuming that this isn't simply by chance, and there's enough data points to assume it's not, there would appear to be a missing explanatory variable here. What explains this change? Perhaps it's a change in the baseball. At leasts, that's what Verlander thinks.
All I’m saying is I don’t care if balls are juiced (seriously). We’re all using the same ball so it’s a fair field. My issue is I don’t like being lied to. I knew something was different. Century old records are being broken and numbers are skewed.
— Justin Verlander (@JustinVerlander) March 2, 2018
It seems Braves pitcher Brandon McCarthy agrees.
I don't know man I got a memo in my locker that said "balls are the same. We said so. Bye.- MLB Science" So, I don't know what to believe.
— Brandon McCarthy (@BMcCarthy32) March 2, 2018
6,107 home runs were hit in 2017, breaking the previous record of 5,693, despite advanced performance-enhancing drug tests and an overall increase in strikeouts.
During the World Series, Sports Illustrated's Tom Verducci reported that the baseballs used in the Fall Classic were slicker than those used in the regular season.
