2 seam fastball aka sinker

#1

I have been working on my sinker ball…i practice on my own against the wall. At times I notice the ball sinking downward before it hits the wall. Now how would I determine if this is for real nad not just my imagination?

Any tips on the griping or anything else.

Thanks so much

#2

Find someone to throw with or even just stand behind a fence when you throw or set up a camera behind a fence (on a bench or chair) and video tape your pitches and watch it after.