A Shift to the Right
Because so many more pitchers throw righthanded than lefthanded, lefthanded hitters have a tremendous advantage at the plate. That's why only once in this century have righthanded batters outhit lefties in either league over a full season. (Actually, it wasn't really a full season: In the strike-shortened 1981 season, American League righthanders outhit lefthanders .256 to .254.) But through last Saturday righthanded batters were dominating the AL.
The American League righties were outhitting lefties by a lusty nine points (.259 to .250). And even though 20 of the last 25 batting titles in the league have been won by lefthanded batters, not a single lefty was among the league's top five hitters. Never in the 91-year history of the American League has a lefty failed to finish among the top five in hitting.
Over in the National League things are more normal. As of Saturday lefthanded batters were averaging 25 points higher than righthanders (.264 to .239), and the leading five hitters in the league included no one who bats exclusively righthanded.
But pitching doesn't account for this disparity. Southpaws have pitched 36% of the innings played in the National League this year, compared with only 27% in the American League.