Report: Thicker laces in baseballs may be reason behind more home runs, pitcher blisters

We may have a reason for why home run rates have been up across Major League Baseball for over two years now — and an explanation for another recent phenomenon.

Writing for the Athletic, Dr. Meredith Wills dismantled 26 baseballs, 12 of which came from 2014 and the other 14 from 2016 and 2017. While she found that virtually everything about the baseballs was identical, there was one notable difference — the laces in the newer baseballs are nine percent thicker than those in the older ones.

Wills explains that this is a significant issue for two reasons.

While it is unclear how much spherical symmetry would be gained from a 9.0% increase in lace thickness, it is unreasonable to assume that it would not make some contribution to drag reduction, thereby allowing the ball to carry farther.

Another likely consequence of thicker laces is the “epidemic” of pitcher blisters that began in 2016. Increased lace thickness will produce slightly prouder stitches (not to be confused with seam height, which is related to lace tightness and cover fit), creating a “bumpier” seam. Since blisters are often associated with tightly gripping or rubbing the seams, the rougher texture could be a strong factor in higher rates of blistering. In fact, the possibility of thicker stitches was even postulated by pitcher Rich Hill last year, although the follow-up was minimal.

Wills notes that a larger sample size would be needed to make a firmer conclusion, and that there are many possible reasons for a change in the laces. That includes a supplier adjustment that even Rawlings may not have been aware of. That said, it’s clear there’s something in play here.

Some pitchers have long believed that the baseballs are juiced, but it may be simpler than that, based on this evidence.