The anticipated clampdown already appears to have had an impact.
Fastball spin rates averaged 2,306-2,329 revolutions per minute each week from the start of the season though June 5, according to MLB Statcast data.
Following an owners’ meeting on June 3 when talk of a crackdown emerged, the average declined to 2,282 during the week of June 6 and dropped to 2,226 on Sunday.
The major league batting average was .232 through April, down from .252 two years ago and under the record low of .237 set in 1968, and it was .236 through May, its lowest since 1968.
The average rose to .247 in the week of June 6, lifting the season average to .238.
The strikeout percentage since June 3 is 23.4%, down from 24.2% until then, and the walk percentage is 8.4%, down from 8.9%.
While Bill Miller, president of the Major League Umpires Association, was quoted as being supportive in the announcement.
Players’ association head Tony Clark, a former first baseman, said the union was discussing the matter with players and with MLB.
“The question becomes whether rosin is sufficient or we should consider approved alternatives,” Clark said. “This question has become more important given the changes and lack of consistency in the baseball in recent years.”