Juice Ball

Rob Neyer reacts to a story in the Hardball Times annual about the ball possibly being responsible for the increased offense in the major leagues after the all-star break:

And whaddayaknow, home runs were way, way up in 2015. They were up not because all those big boys were making more contact (again, they weren’t) but rather because when they did make contact, a significantly higher percentage of batted balls were flying over the outfield walls. In the second half of 2015, 4.1 percent of batted balls became home runs. That 4.1 percent is one of the five highest half-season percentages since the 2000 season … and (here’s the kicker!) three of the other four were in 2000 and 2001 (with the fourth in 2004).

Home runs alone, however, do not make enough of a case for a juiced ball. If other hits and walks are tougher to come by, then batters adjusting their swings to hit more home runs might do the trick. We want to see some evidence that all balls are hit harder. It turns out that BABIP (Hits-HR)/(AB-(HR+K)) was also up in the second half of the season. The BABIP was .300 before the all-star break, .304 after. Since harder hit balls tend to go for hits, either batters were making better contact, or the balls were jumping off the bat faster.

The interesting thing is MLB knows the answer. Trackman measures bat speed and the velocity of the ball. Someone needs to compare velocities off the bat at the same bat speed before and after the break to see if it was the ball or the hitters.

Here’s a graph of runs per game per week so you can graphically see the rise in offense.

from baseballmusings.com http://ift.tt/1ODkyVe