Hitting a curve ball starts with seeing the pitch
Hitting a curveball comes from recognizing the pitch as it’s thrown. While challenging, the goal should be to learn how to pick up the rotation of the ball as soon as the pitcher releases the ball from his hand.
By learning how to recognize each pitch as it’s thrown, the batter will have a much better chance of making contact. There are a few subtleties you can look for:
Release Point: Each pitcher has a release point, depending their type of delivery—overhand, three-quarters, sidearm, the release points for each pitcher can vary.
Watch the pitcher’s throwing hand: If his/her fingers are set up behind the ball at the point of delivery, it’s likely going to be a fastball. If his fingers are set up more to the side of the ball, chances are the batter will see a curveball coming their way.
At a younger age, pitchers haven’t developed the technique of throwing a fastball and curveball with a uniform motion. Kids have a tendency to slow down their pitching motions or you can easily see pitchers change their grip on the ball before they throw a breaking pitch. These are little things you can look for.