Why was hitting for average in the American League so hard in 1968, and what is the significance of Carl Yastrzemski being the only one to achieve a .300batting average?

While the Dead Ball Era (1900-1919) was a great time for pitchers, 1968 is generally considered the “Year of the Pitcher.” This title is especially appropriate for the American League, where the league slugging percentage (.340) was the lowest since 1915, and on-base percentage (.300) was the lowest since 1908. Batting averages suffered especially, falling to their lowest point (.231) in history, worse than the deadest of the dead-ball years. The two best teams in baseball, Detroit and St. Louis, were led by the two best pitchers in baseball. Detroit’s Denny McLain cruised to a 31-6 record, the first man to win 30 since Dizzy Dean in 1934. St. Louis’s Bob Gibson won 22 games while posting a miniscule 1.12 ERA, the fourth smallest in history and lowest since Dutch Leonard’s 0.96 in 1914. Both men won the Cy Young Award and the MVP. Other pitchers followed their lead, with both the AL and NL posting ERAs under 3.00, the first time that had happened since 1918.

Just as rule changes had caused an offensive explosion in 1920, the plunging offensive numbers in 1968 were the culmination of rule changes in 1963. Commissioner Ford Frick, troubled by the record number of home runs in the early ‘60s, convinced owners to raise the pitcher’s mound and widen the strike zone from the top of the armpit to the bottom of the knee. This caused many more pitchers’ counts, which in turn caused batting averages to plummet. Indeed, Carl Yastrzemski was the only American Leaguer to hit over .300 that year. In fact, he was the only one to hit over .290. His .301 average was the lowest ever to win a batting title. The powers-that-be quickly realized that they had created a monster, so the next year they again lowered the mound and shrunk the strike zone back to its original size. Batting averages returned to their normal level, and Rod Carew won the AL batting title with a .332 average.