"You have to have a catcher because if you don't you're likely to have a lot of passed balls"

This quote by Casey Stengel is referring to the value of having a catcher in baseball. A catcher is a player who supports the batter and catches the ball when it is tossed by the pitcher. Without a catcher, the ball would be thrown and there would be nobody to catch it, resulting in a lot of passed balls. This would be a big downside for the group, as it would provide the opposing group an advantage. Stengel is emphasizing the value of having a catcher in order to avoid the opposing team from gaining an advantage. He is likewise highlighting the significance of having a catcher in order to prevent the ball from being tossed and not caught, resulting in a great deal of passed balls. By having a catcher, the team can prevent the opposing team from acquiring a benefit and can also prevent a great deal of passed balls.