Cardinals claim playoff baseballs have lost juice

The St. Louis Cardinals’ front office says baseballs have suddenly lost their juice this postseason, supporting a claim from a prominent data scientist that the balls have changed following a historic, homer-friendly regular season.

Cardinals manager Mike Shildt said Saturday that

St. Louis’ analytics department has found the ball is flying 4½ fewer feet on average in the postseason. Players in both leagues have been stunned when hard-hit balls have fallen on the warning track this month, raising more questions about the makeup of the baseballs after hitters clubbed a record 6,776 home runs in the regular season — a rise attributed to unusually far-flying balls.

“I mean there’s probably all kind of different theories behind that that I won’t really get into,” Shildt said. “Just the fact of the matter, it could be any number of things.”

The numbers don’t leave much doubt, says data journalist Rob Arthur. He was among the first to suggest tweaks to the ball may have caused home runs to spike as early as 2015, and he thinks something is off with this year’s October model, too.

Arthur published a story Thursday at Baseball Prospectus showing the postseason balls have more air resistance than the regular season balls, according to data pulled from MLB’s own tracking system. Arthur projected home runs were down 50 percent through Wednesday’s games compared to what would have been expected in the 2019 scoring environment, even though the average temperature for playoff games was higher than the regular season to that point.