MLB Slightly Deadening Ball Due To HR Surge

The Athletic’s Eno Sarris and Ken Rosenthal broke the news along with the incredible details of Major League Baseball’s plan to tweak the ball. The focus seems to be on not overemphasizing the home run but safety has to be part of the equation. Either way, chicks digging the long ball appears to be taking a back seat to the game getting played at a faster clip with less emphasis on the home run.

Golfers will enjoy hearing about COR…

“In an effort to center the ball with the specification range for COR and CCOR, Rawlings produced a number of baseballs from late 2019 through early 2020 that loosened the tension of the first wool winding,” the memo from the office of the commissioner reads, explaining that this change had two effects — reducing the weight of the ball by less than one-tenth of an ounce, and also a slight decrease in the bounciness of the ball as measured by the COR and CCOR. 

COR is the coefficient of restitution, or the relationship of the incoming speed to the outgoing speed. So, in other words, this new ball will be less bouncy. How much less is a matter of science, but also opinion.

Research conducted by Rawlings says the balls will be centered more in the midpoint of the established COR range, which is from .530 to .570 with a midpoint around .550, as the (now missing) first report on the home run rate surge stated. So the COR likely changed around .01 to .02 at most, and the ball size was likely reduced by less than 2.8 grams.

AP’s Jake Seiner added this:

MLB anticipates the changes will be subtle, and a memo to teams last week cited an independent lab that found the new balls will fly 1 to 2 feet shorter when hit over 375 feet. Five teams also plan to add humidors to their stadiums, raising the total to 10 of 30 MLB stadiums equipped with humidity-controlled storage spaces.