1)18 is the maximum number of players on a teams roster. 15 is the recommended minimum number of players on a teams roster( but not required).
2)Junior and Intermediate Divisions:
Pitching distance=33 feet Baselines=50 feet
Teen Division:
Pitching distances=35 feet Baselines=55
Tyro, Senior Division:
Pitching distances=40 feet Baselines=60 feet
3) There are 10 players on a field at a time (the batter,pitcher,1st baseman, 2nd baseman, shorstop,3rd baseman, right field, left field and center field). In the younger leagues 4 outfielders instead of 3.
4) In younger leagues you cannot leave the base to steal until the ball has passed the plate. In older leagues you can leave the base right after the pitcher releases the ball.
5)3 strikes and you are out.
6)4 balls and you walk.
7)After 4 walks in the younger leaguesthere are no more walks you have to get a hit or get struck out.