WAUPACA, WI-MAY 20, 2018: Ryder Vergauwen, 10, yells in excitement while holding a new USA Baseball approved bat after hitting a home run in home run derby at the end of practice. Players on the 10U Waupaca baseball team practice Sunday, May 20 at Swan Park in Waupaca, Wisc. USA Baseball has created a new standard for baseball bats that requires a specific barrel size, rendering most previously approved bats unacceptable for play. Lauren Justice for The New York Times