The horseshoe shape of the seams should be opened upward. [substeps] Experiment with your fingers resting just inside the seams as opposed to directly on top of them.
[header] How to throw a great two seam fastball [title] Place your index finger and middle finger on the seams. [step] Find the part of the seams where the gap between them is narrowest. Lay each finger so it runs parallel with one of the seams.