August 20th, 1923 - A four-piece bat used by Babe Ruth is banned by American League president Ban Johnson because of the glue used on it. Johnson rules that all bats must be one piece with nothing added except tape extending to 18 inches up the handle.
On August 20th, 1934 Lou Gehrig hits a first-inning grand slam off A’s pitcher Buck Ross in an 11-3 Yankee win. It is the 23rd and last grand slam of his career for a still-standing record.
August 20th, 1960, Ted Williams joins Babe Ruth as the only batters to collect 2,000 walks during the Red Sox's split of a twi-night doubleheader with Baltimore.
August 20th, 1965, Eddie Mathews hits his 28th home run as the Braves win 4-3 at Pittsburgh. The Braves duo of Mathews and Hank Aaron, from ‘54 to ‘65, becomes the top home run duo in major league history, passing the Ruth-Gehrig total of 772 home runs while they were Yankee teammates.
August 20th, 1989, Howard Johnson hits his 30th home run of the season in the Mets' 5 - 4 loss ...