Modern baseball may have found its birth certificate. And with it a new birth date, and new founding father. Coinciding with the start of the major league season, a set of game-changing documents went up for sale this week. Their authenticity and significance are verified by experts including John Thorn, Major League Baseball’s official historian. The 1857 documents titled “Laws of Base Ball” establish the essentials of the modern game: The distance of the base paths is 90 feet, the length of the game is nine innings and nine players are in the field.