The use of standard blue screen techniques for doing matte shots of the birds proved to be unacceptable. The rapid movement of the birds, especially their wings, caused excessive blue fringing in the shots. It was determined that the sodium vapor process could be used to do the composites.
As far as MLB goes, each team plays 162 games in a season ... 81 home games and 81 games on the road.
Major league baseball is a league of 30 professional baseball teams in the United States and Canada. The MLB was founded in 1869. Teams compete from April to October, when the World Series is held.