Curveball would be a Special Ability that lowers the batter's Bat stat, while Fastball would increase the pitcher's Throw stat (while pitching). If the pitcher wins, the batter is given a strike. If the pitcher rolls all ones, that counts as a ball. A tie is a bunt or foul, and the batter rolling all ones is an infield catch (batter is out).
After the batter hits, roll another die. 1, it goes straddling the left foul line; 2, it goes between 3rd and 2nd base ; 3, it goes to the left of 2nd base over the short stop; 4, it goes to the right of 2nd base over the second baseman; 5, it goes flying between 2nd and 1st base; 6, it straddles the right foul line.