Premise: How to throw a spitball<br>Put a small amount of saliva or vaseline on the baseball. The object is to create resistance and a change in the uniform weight of the ball to make its motion more unpredictable and difficult to hit. There's no " right place " to put it, since the object is unpredictability, as with a knuckleball.
Hypothesis: a spitball has a different uniform weight than a regular ball