What is the difference between the four seam orientation and the two seam one?
When you throw a four-seam fastball your fingers are positioned across the seams while a two-seamer (sometimes called a sinker) is thrown with the index and middle fingers placed along the seams. From a catcher’s perspective that means that you would be able to see, if the ball were not spinning so fast, four seams for every revolution as the ball came toward you. With a two seamer you would only see two seams per revolution (click here for graphic). The four seam orientation is our most popular and versatile model.
