Does playing fastball with a tennis ball makes you a better hitter in baseball?
Hitting can be broken down into three segments; SEE, REACT,
SWING. You watch the ball in the pitcher's hand during the windup
and you watch the ball leave the pitcher's hand when it is thrown
and you watch the spin of the ball as it comes towards the plate.
That is SEE. You determine what the pitch is (fastball, curveball,
etc.), you determine where the ball is going to go and you
determine whether it is headed towards an area that you think you
can get good wood on it. That is REACT. You swing if you like the
pitch or don't swing if you don't like the pitch. That is SWING. It
doesn't make any difference whether you are playing with a tennis
ball or a golf ball or a baseball. The theory and mechanics are the
same. So, to answer your question I would say the more you practice
the better you will be, regardless of the type of ball you use to
practice with.