(NABBP) Rules which governed until 1870, the 9-inning format was adopted, replacing the previous rule that the first team to score 21 runs won. The next year, called strikes were recognized, and a batter was out if a ball, fair or foul, was caught on the fly or after one bounce. Called balls and the walk were introduced in 1863. In 1867, the batter had the right to call for a high or low pitch, to be determined by the umpire.

The National League formed