Nike Baseball Tip: Improving Your Throw
Learning how to throw properly can sometimes be difficult for someone just starting out playing. A great drill is the Black Line Drill.
With a base place a piece of black electrical tape or a black line with a sharpie perpendicular to the seams. This line should wrap around the entire ball. Kneel on one knee of the throwing arm and place the one leg out in front. Put three fingers across the seam of the ball and the thumb below the ball on the black line. Practice throwing using the glove hand to point to the intended target. If throwing properly, the black line should be spinning vertically. If the line is spinning off or wobbles, then the follow through is not over the top, but is coming sideways.
Keep practicing with this drill until the black line spinning vertical becomes consistent.