What are Seam Stamps?
Seam Stamps is a baseball shaped stencil that gives each athlete immediate feedback on the seam orientation of each throw they make.
How do you use it?
By using Seam Stamps, you can draw markings on your baseballs to track 4-Seam, 2-Seam, and 1-Seam orientations. Simply apply the stencil to the ball, throw it, and watch the markings. If the lines remain stable in flight, you've achieved the desired seam orientation. If the lines wobble or shift, it signals that your seam orientation is off.
With Seam Stamps, you don’t need expensive tracking systems or cameras to monitor your seam orientation. While iPhone slow-motion videos can capture the markings for more detailed analysis, the beauty of Seam Stamps is that it’s just as effective during regular catch play—simply use your eyes to observe how the lines behave as the ball travels. Whether you're practicing on the mound or working with a catcher, the immediate visual feedback from the seam markings allows you to adjust your grip and release without the need for specialized equipment, making it an accessible tool for players at any level.
What is Seam Orientation?
Spin influences pitch movement by creating air pressure differences around the entire baseball. The direction and speed of the spin—such as backspin, topspin, or sidespin—determine whether the ball rises, drops, or moves horizontally.
Seam orientation influences movement by affecting how air interacts with the seams. Different seam orientations alter the airflow around the ball, causing the pitch movement direction to deviate from the spin direction.
Read more below to learn how specific seam orientations can affect pitch movement.