Did they dejuice the baseball? Did they rejuice the baseball? The answer is both, depending on the day. MLB seems to have very little control over the baseball's performance: sometimes it's the rocket ball, sometimes it's lead by comparison. baseballprospectus.com/news/article/5… 
Every day the ball fluctuates over a huge range of drag coefficients, and I found there's a direct connection between that fluctuation and how the ball performs that day (in terms of home run probability and fly ball distance).
When you get down to a single day or even single game, the sample sizes are small, but the fluctuations in drag are so large and the consequences on fly ball distance so visible that there is very little chance these changes are because of inaccurate data.
Now what's surprising is that, despite MLB claiming that Rawlings has improved the quality control of the baseballs, this postseason has had even more variation from ball to ball and game to game than recent previous years.
Some scientists now on MLB's commission studying the ball did an experiment where they opened up different batches of baseballs and tested how far they flew out of a pitching machine. One batch went *11 feet further* than the other. That was in 2014.
So I suspect this has been a problem for a long time--maybe the whole duration of the game. But the recent performance of the baseball has swerved around between extremes that are altering and increasing the home run rate more than ever.
Now that we know it's an issue--and we've known since at least 2017, with the commission validating my findings in 2018--can MLB just sweep it back under the rug?
