1866 December

12th  The 10th annual convention of the National Association of Base Ball Players is held at Clinton Hall in NYC with a record 202 clubs sending delegates. Rule changes include the introduction of called balls, after a warning of course, with 3 called balls allowing the batter to 1B. This session introduces the pitcher’s box, an area 6 feet wide and 4 feet deep, from which the pitcher must deliver the ball.