what is a sinker press
Sinker (baseball) In baseball, a sinker or sinking fastball is a type of fastball pitch which has significant downward and horizontal movement and is known for inducing ground balls. Pitchers who use the sinker tend to rely on it heavily and do not need to change pitch speeds as much as other pitchers do because the sinking action induces weak bat contact. Other pitchers normally change pitch speeds to achieve this effect. The sinker is much more often used by right-handed than left-handed pitchers.