What Am I?

Clue 1: I am a team sport. You need to join a team if you want to play me.

Clue 2: Two teams play each other to see who can score the most points.

Clue 3: You hit a ball with a bat when you play me but I am not cricket.

Clue 4: The person who throws the ball towards the batter is called the pitcher.

Clue 5: You play me on a field shaped like a diamond.

Clue 6: You must run around all 4 of my bases to score a point called a "run".